More predictable Downloader::startDownload()

Before this change `Downloader::startDownload()` might avoid starting a
new download when a download with the specified URI was already present
in its cache. This might be confusing for the following reasons:

1. uri is not the only parameter of `Downloader::startDownload()` - a
   target download directory may also be specified through the second
   `options` parameter. Thus calling `Downloader::startDownload()` twice
   with the same URI but different download directories would not save
   files into the second directory.

2. Files of a completed download may be removed, whereupon downloading the same
   files again won't be a no-op. However in such a situation
   `Downloader` refuses to actually repeat a previous download.

.github/workflows/ci.yml

@@ -8,7 +8,17 @@ on:
 
 jobs:
   macOS:
-    runs-on: macos-13
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-13
+        target:
+          - native_dyn
+          - iOS_arm64
+          - iOS_x86_64
+    runs-on: ${{ matrix.os }}
+
     env:
       HOME: /Users/runner
     steps:
@@ -22,22 +32,31 @@ jobs:
           # upgrade from python@3.11.2_1 to python@3.11.3 fails to overwrite those
           rm -f /usr/local/bin/2to3 /usr/local/bin/2to3-3.11 /usr/local/bin/idle3 /usr/local/bin/idle3.11 /usr/local/bin/pydoc3 /usr/local/bin/pydoc3.11 /usr/local/bin/python3 /usr/local/bin/python3-config /usr/local/bin/python3.11 /usr/local/bin/python3.11-config
           brew install pkg-config ninja meson
+        env:
+          HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
 
       - name: Install dependencies
-        env:
-          ARCHIVE_NAME: deps2_macos_native_dyn_libkiwix.tar.xz
-        run: |
-          wget -O- https://tmp.kiwix.org/ci/${{env.ARCHIVE_NAME}} | tar -xJ -C ${{env.HOME}}
+        uses: kiwix/kiwix-build/actions/dl_deps_archive@main
+        with:
+          os_name: macos
+          target_platform: ${{ matrix.target }}
 
-      - name: Compile source code
+      - name: Compile
         env:
-          PKG_CONFIG_PATH: ${{env.HOME}}/BUILD_native_dyn/INSTALL/lib/pkgconfig
+          PKG_CONFIG_PATH: ${{env.HOME}}/BUILD_${{matrix.target}}/INSTALL/lib/pkgconfig
           CPPFLAGS: -I${{env.HOME}}/BUILD_native_dyn/INSTALL/include
+          MESON_OPTION: --default-library=shared -Db_coverage=true
+          MESON_CROSSFILE: ${{env.HOME}}/BUILD_${{matrix.target}}/meson_cross_file.txt
+        shell: bash
         run: |
-          meson . build --default-library=shared -Db_coverage=true
+          if [[ ! "${{matrix.target}}" =~ native_.* ]]; then
+            MESON_OPTION="$MESON_OPTION --cross-file $MESON_CROSSFILE -Dstatic-linkage=true"
+          fi
+          meson . build ${MESON_OPTION}
           ninja -C build
 
       - name: Test libkiwix
+        if: startsWith(matrix.target, 'native_')
         env:
           SKIP_BIG_MEMORY_TEST: 1
           LD_LIBRARY_PATH: ${{env.HOME}}/BUILD_native_dyn/INSTALL/lib:${{env.HOME}}/BUILD_native_dyn/INSTALL/lib64
@@ -87,11 +106,10 @@ jobs:
     steps:
     - name: Checkout code
       uses: actions/checkout@v3
-    - name: Install deps
-      shell: bash
-      run: |
-        ARCHIVE_NAME=deps2_${OS_NAME}_${{matrix.target}}_libkiwix.tar.xz
-        wget -O- http://tmp.kiwix.org/ci/${ARCHIVE_NAME} | tar -xJ -C /home/runner
+    - name: Install dependencies
+      uses: kiwix/kiwix-build/actions/dl_deps_archive@main
+      with:
+        target_platform: ${{ matrix.target }}
     - name: Compile
       shell: bash
       run: |

include/search_renderer.h

@@ -72,6 +72,13 @@ class SearchRenderer
     this->pageLength  = pageLength;
   }
 
+  /**
+   * set user language
+   */
+  void setUserLang(const std::string& lang){
+    this->userlang  = lang;
+  }
+
   /**
    * Generate the html page with the resutls of the search.
    *
@@ -105,6 +112,7 @@ class SearchRenderer
   unsigned int pageLength;
   unsigned int estimatedResultCount;
   unsigned int resultStart;
+  std::string userlang = "en";
 };
 
 

src/downloader.cpp

@@ -169,12 +169,6 @@ std::vector<std::string> Downloader::getDownloadIds() const {
 std::shared_ptr<Download> Downloader::startDownload(const std::string& uri, const std::vector<std::pair<std::string, std::string>>& options)
 {
   std::unique_lock<std::mutex> lock(m_lock);
-  for (auto& p: m_knownDownloads) {
-    auto& d = p.second;
-    auto& uris = d->getUris();
-    if (std::find(uris.begin(), uris.end(), uri) != uris.end())
-      return d;
-  }
   std::vector<std::string> uris = {uri};
   auto gid = mp_aria->addUri(uris, options);
   m_knownDownloads[gid] = std::make_shared<Download>(mp_aria, gid);

src/search_renderer.cpp

@@ -32,9 +32,42 @@
 #include "libkiwix-resources.h"
 #include "tools/stringTools.h"
 
+#include "server/i18n.h"
+
 namespace kiwix
 {
 
+namespace
+{
+
+ParameterizedMessage searchResultsPageTitleMsg(const std::string& searchPattern)
+{
+  return ParameterizedMessage("search-results-page-title",
+                              {{"SEARCH_PATTERN", searchPattern}}
+  );
+}
+
+ParameterizedMessage searchResultsPageHeaderMsg(const std::string& searchPattern,
+                                                const kainjow::mustache::data& r)
+{
+  if ( r.get("count")->string_value() == "0" ) {
+    return ParameterizedMessage("empty-search-results-page-header",
+                                {{"SEARCH_PATTERN", searchPattern}}
+    );
+  } else {
+    return ParameterizedMessage("search-results-page-header",
+                                {
+                                  {"SEARCH_PATTERN", searchPattern},
+                                  {"START", r.get("start")->string_value()},
+                                  {"END",   r.get("end")  ->string_value()},
+                                  {"COUNT", r.get("count")->string_value()},
+                                }
+    );
+  }
+}
+
+} // unnamed namespace
+
 /* Constructor */
 SearchRenderer::SearchRenderer(zim::SearchResultSet srs,
                       unsigned int start, unsigned int estimatedResultCount)
@@ -170,10 +203,20 @@ std::string SearchRenderer::renderTemplate(const std::string& tmpl_str, const Na
     result.set("absolutePath", absPathPrefix + urlEncode(path));
     result.set("snippet", it.getSnippet());
     if (library) {
-      result.set("bookTitle", library->getBookById(zim_id).getTitle());
+      const std::string bookTitle = library->getBookById(zim_id).getTitle();
+      const ParameterizedMessage bookInfoMsg("search-result-book-info",
+          {{"BOOK_TITLE", bookTitle}}
+      );
+      result.set("bookInfo",  bookInfoMsg.getText(userlang)); // for HTML
+      result.set("bookTitle", bookTitle); // for XML
     }
     if (it.getWordCount() >= 0) {
-      result.set("wordCount", kiwix::beautifyInteger(it.getWordCount()));
+      const auto wordCountStr = kiwix::beautifyInteger(it.getWordCount());
+      const ParameterizedMessage wordCountMsg("word-count",
+          {{"COUNT", wordCountStr}}
+      );
+      result.set("wordCountInfo", wordCountMsg.getText(userlang)); // for HTML
+      result.set("wordCount", wordCountStr); // for XML
     }
 
     items.push_back(result);
@@ -181,7 +224,6 @@ std::string SearchRenderer::renderTemplate(const std::string& tmpl_str, const Na
   kainjow::mustache::data results;
   results.set("items", items);
   results.set("count", kiwix::beautifyInteger(estimatedResultCount));
-  results.set("hasResults", estimatedResultCount != 0);
   results.set("start", kiwix::beautifyInteger(resultStart));
   results.set("end", kiwix::beautifyInteger(std::min(resultStart+pageLength-1, estimatedResultCount)));
 
@@ -198,12 +240,15 @@ std::string SearchRenderer::renderTemplate(const std::string& tmpl_str, const Na
     searchBookQuery
   );
 
-
-  kainjow::mustache::data allData;
-  allData.set("searchProtocolPrefix", searchProtocolPrefix);
-  allData.set("results", results);
-  allData.set("pagination", pagination);
-  allData.set("query", query);
+  const auto pageHeaderMsg = searchResultsPageHeaderMsg(searchPattern, results);
+  const kainjow::mustache::object allData{
+    {"PAGE_TITLE", searchResultsPageTitleMsg(searchPattern).getText(userlang)},
+    {"PAGE_HEADER", pageHeaderMsg.getText(userlang)},
+    {"searchProtocolPrefix", searchProtocolPrefix},
+    {"results", results},
+    {"pagination", pagination},
+    {"query", query},
+  };
 
   kainjow::mustache::mustache tmpl(tmpl_str);
 

src/server/i18n.cpp

@@ -112,8 +112,12 @@ std::string expandParameterizedString(const std::string& lang,
                                       const std::string& key,
                                       const Parameters& params)
 {
+  kainjow::mustache::object mustacheParams;
+  for( const auto& kv : params ) {
+    mustacheParams[kv.first] = kv.second;
+  }
   const std::string tmpl = getTranslatedString(lang, key);
-  return render_template(tmpl, params);
+  return render_template(tmpl, mustacheParams);
 }
 
 } // namespace i18n

src/server/i18n.h

@@ -20,6 +20,7 @@
 #ifndef KIWIX_SERVER_I18N
 #define KIWIX_SERVER_I18N
 
+#include <map>
 #include <string>
 #include <mustache.hpp>
 
@@ -44,7 +45,7 @@ std::string getTranslatedString(const std::string& lang, const std::string& key)
 namespace i18n
 {
 
-typedef kainjow::mustache::object Parameters;
+typedef std::map<std::string, std::string> Parameters;
 
 std::string expandParameterizedString(const std::string& lang,
                                       const std::string& key,
@@ -93,10 +94,10 @@ private:
 
 } // namespace i18n
 
-struct ParameterizedMessage
+class ParameterizedMessage
 {
 public: // types
-  typedef kainjow::mustache::object Parameters;
+  typedef i18n::Parameters Parameters;
 
 public: // functions
   ParameterizedMessage(const std::string& msgId, const Parameters& params)
@@ -106,11 +107,20 @@ public: // functions
 
   std::string getText(const std::string& lang) const;
 
+  const std::string& getMsgId()  const { return msgId; }
+  const Parameters&  getParams() const { return params; }
+
 private: // data
   const std::string msgId;
   const Parameters  params;
 };
 
+inline ParameterizedMessage nonParameterizedMessage(const std::string& msgId)
+{
+  const ParameterizedMessage::Parameters noParams;
+  return ParameterizedMessage(msgId, noParams);
+}
+
 struct LangPreference
 {
   const std::string lang;

src/server/internalServer.cpp

@@ -190,12 +190,6 @@ ParameterizedMessage tooManyBooksMsg(size_t nbBooks, size_t limit)
   );
 }
 
-ParameterizedMessage nonParameterizedMessage(const std::string& msgId)
-{
-  const ParameterizedMessage::Parameters noParams;
-  return ParameterizedMessage(msgId, noParams);
-}
-
 struct Error : public std::runtime_error {
   explicit Error(const ParameterizedMessage& message)
     : std::runtime_error("Error while handling request"),
@@ -519,6 +513,19 @@ static MHD_Result staticHandlerCallback(void* cls,
                                 cont_cls);
 }
 
+namespace
+{
+
+MHD_Result add_name_value_pair(void *nvp, enum MHD_ValueKind kind,
+                               const char *key, const char *value)
+{
+  auto& nameValuePairs = *reinterpret_cast<RequestContext::NameValuePairs*>(nvp);
+  nameValuePairs.push_back({key, value});
+  return MHD_YES;
+}
+
+} // unnamed namespace
+
 MHD_Result InternalServer::handlerCallback(struct MHD_Connection* connection,
                                            const char* fullUrl,
                                            const char* method,
@@ -535,7 +542,10 @@ MHD_Result InternalServer::handlerCallback(struct MHD_Connection* connection,
   }
 
   const auto url = fullURL2LocalURL(fullUrl, m_rootPrefixOfDecodedURL);
-  RequestContext request(connection, m_root, url, method, version);
+  RequestContext::NameValuePairs headers, queryArgs;
+  MHD_get_connection_values(connection, MHD_HEADER_KIND, add_name_value_pair, &headers);
+  MHD_get_connection_values(connection, MHD_GET_ARGUMENT_KIND, add_name_value_pair, &queryArgs);
+  RequestContext request(m_root, url, method, version, headers, queryArgs);
 
   if (m_verbose.load() ) {
     request.print_debug_info();
@@ -564,7 +574,7 @@ MHD_Result InternalServer::handlerCallback(struct MHD_Connection* connection,
     response->set_etag_body(getLibraryId());
   }
 
-  auto ret = response->send(request, connection);
+  auto ret = response->send(request, m_verbose.load(), connection);
   auto end_time = std::chrono::steady_clock::now();
   auto time_span = std::chrono::duration_cast<std::chrono::duration<double>>(end_time - start_time);
   if (m_verbose.load()) {
@@ -593,20 +603,19 @@ std::unique_ptr<Response> InternalServer::handle_request(const RequestContext& r
 {
   try {
     if (! request.is_valid_url()) {
-      return HTTP404Response(*this, request)
-             + urlNotFoundMsg;
+      return UrlNotFoundResponse(request);
     }
 
     if ( request.get_url() == "" ) {
       // Redirect /ROOT_LOCATION to /ROOT_LOCATION/ (note the added slash)
       // so that relative URLs are resolved correctly
       const std::string query = getSearchComponent(request);
-      return Response::build_redirect(*this, m_root + "/" + query);
+      return Response::build_redirect(m_root + "/" + query);
     }
 
     const ETag etag = get_matching_if_none_match_etag(request, getLibraryId());
     if ( etag )
-      return Response::build_304(*this, etag);
+      return Response::build_304(etag);
 
     const auto url = request.get_url();
     if ( isLocallyCustomizedResource(url) )
@@ -647,15 +656,15 @@ std::unique_ptr<Response> InternalServer::handle_request(const RequestContext& r
 
     const std::string contentUrl = m_root + "/content" + urlEncode(url);
     const std::string query = getSearchComponent(request);
-    return Response::build_redirect(*this, contentUrl + query);
+    return Response::build_redirect(contentUrl + query);
   } catch (std::exception& e) {
     fprintf(stderr, "===== Unhandled error : %s\n", e.what());
-    return HTTP500Response(*this, request)
-         + e.what();
+    return HTTP500Response(request)
+         + ParameterizedMessage("non-translated-text", {{"MSG", e.what()}});
   } catch (...) {
     fprintf(stderr, "===== Unhandled unknown error\n");
-    return HTTP500Response(*this, request)
-         + "Unknown error";
+    return HTTP500Response(request)
+         + nonParameterizedMessage("unknown-error");
   }
 }
 
@@ -668,7 +677,7 @@ MustacheData InternalServer::get_default_data() const
 
 std::unique_ptr<Response> InternalServer::build_homepage(const RequestContext& request)
 {
-  return ContentResponse::build(*this, m_indexTemplateString, get_default_data(), "text/html; charset=utf-8");
+  return ContentResponse::build(m_indexTemplateString, get_default_data(), "text/html; charset=utf-8");
 }
 
 /**
@@ -697,8 +706,7 @@ std::unique_ptr<Response> InternalServer::handle_suggest(const RequestContext& r
   }
 
   if ( startsWith(request.get_url(), "/suggest/") ) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   std::string bookName, bookId;
@@ -712,7 +720,7 @@ std::unique_ptr<Response> InternalServer::handle_suggest(const RequestContext& r
   }
 
   if (archive == nullptr) {
-    return HTTP404Response(*this, request)
+    return HTTP404Response(request)
            + noSuchBookErrorMsg(bookName);
   }
 
@@ -747,7 +755,7 @@ std::unique_ptr<Response> InternalServer::handle_suggest(const RequestContext& r
     results.addFTSearchSuggestion(request.get_user_language(), queryString);
   }
 
-  return ContentResponse::build(*this, results.getJSON(), "application/json; charset=utf-8");
+  return ContentResponse::build(results.getJSON(), "application/json; charset=utf-8");
 }
 
 std::unique_ptr<Response> InternalServer::handle_viewer_settings(const RequestContext& request)
@@ -759,10 +767,9 @@ std::unique_ptr<Response> InternalServer::handle_viewer_settings(const RequestCo
   const kainjow::mustache::object data{
     {"enable_toolbar", m_withTaskbar ? "true" : "false" },
     {"enable_link_blocking", m_blockExternalLinks ? "true" : "false" },
-    {"enable_library_button", m_withLibraryButton ? "true" : "false" },
-    {"default_user_language", request.get_user_language() }
+    {"enable_library_button", m_withLibraryButton ? "true" : "false" }
   };
-  return ContentResponse::build(*this, RESOURCE::templates::viewer_settings_js, data, "application/javascript; charset=utf-8");
+  return ContentResponse::build(RESOURCE::templates::viewer_settings_js, data, "application/javascript; charset=utf-8");
 }
 
 std::string InternalServer::getNoJSDownloadPageHTML(const std::string& bookId, const std::string& userLang) const
@@ -817,19 +824,13 @@ std::unique_ptr<Response> InternalServer::handle_no_js(const RequestContext& req
       const auto bookId = mp_nameMapper->getIdForName(urlParts[2]);
       content = getNoJSDownloadPageHTML(bookId, userLang);
     } catch (const std::out_of_range&) {
-      return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+      return UrlNotFoundResponse(request);
     }
   } else {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
-  return ContentResponse::build(
-             *this,
-             content,
-             "text/html; charset=utf-8"
-  );
+  return ContentResponse::build(content, "text/html; charset=utf-8");
 }
 
 namespace
@@ -867,14 +868,12 @@ std::unique_ptr<Response> InternalServer::handle_skin(const RequestContext& requ
   try {
     const auto accessType = staticResourceAccessType(request, resourceCacheId);
     auto response = ContentResponse::build(
-        *this,
         getResource(resourceName),
         getMimeTypeForFile(resourceName));
     response->set_kind(accessType);
     return std::move(response);
   } catch (const ResourceNotFound& e) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 }
 
@@ -887,20 +886,17 @@ std::unique_ptr<Response> InternalServer::handle_search(const RequestContext& re
   if ( startsWith(request.get_url(), "/search/") ) {
     if (request.get_url() == "/search/searchdescription.xml") {
       return ContentResponse::build(
-        *this,
         RESOURCE::ft_opensearchdescription_xml,
         get_default_data(),
         "application/opensearchdescription+xml");
     }
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   try {
     return handle_search_request(request);
   } catch (const Error& e) {
-    return HTTP400Response(*this, request)
-      + invalidUrlMsg
+    return HTTP400Response(request)
       + e.message();
   }
 }
@@ -942,10 +938,11 @@ std::unique_ptr<Response> InternalServer::handle_search_request(const RequestCon
     // Searcher->search will throw a runtime error if there is no valid xapian database to do the search.
     // (in case of zim file not containing a index)
     const auto cssUrl = renderUrl(m_root, RESOURCE::templates::url_of_search_results_css);
-    HTTPErrorResponse response(*this, request, MHD_HTTP_NOT_FOUND,
+    HTTPErrorResponse response(request, MHD_HTTP_NOT_FOUND,
                                "fulltext-search-unavailable",
                                "404-page-heading",
-                               cssUrl);
+                               cssUrl,
+                               /*includeKiwixResponseData=*/true);
     response += nonParameterizedMessage("no-search-results");
     // XXX: Now this has to be handled by the iframe-based viewer which
     // XXX: has to resolve if the book selection resulted in a single book.
@@ -970,15 +967,14 @@ std::unique_ptr<Response> InternalServer::handle_search_request(const RequestCon
   renderer.setProtocolPrefix(m_root + "/content/");
   renderer.setSearchProtocolPrefix(m_root + "/search");
   renderer.setPageLength(pageLength);
+  renderer.setUserLang(request.get_user_language());
   if (request.get_requested_format() == "xml") {
     return ContentResponse::build(
-      *this,
       renderer.getXml(*mp_nameMapper, mp_library.get()),
       "application/rss+xml; charset=utf-8"
     );
   }
   auto response = ContentResponse::build(
-    *this,
     renderer.getHtml(*mp_nameMapper, mp_library.get()),
     "text/html; charset=utf-8"
   );
@@ -1001,8 +997,7 @@ std::unique_ptr<Response> InternalServer::handle_random(const RequestContext& re
   }
 
   if ( startsWith(request.get_url(), "/random/") ) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   std::string bookName;
@@ -1016,7 +1011,7 @@ std::unique_ptr<Response> InternalServer::handle_random(const RequestContext& re
   }
 
   if (archive == nullptr) {
-    return HTTP404Response(*this, request)
+    return HTTP404Response(request)
            + noSuchBookErrorMsg(bookName);
   }
 
@@ -1024,7 +1019,7 @@ std::unique_ptr<Response> InternalServer::handle_random(const RequestContext& re
     auto entry = archive->getRandomEntry();
     return build_redirect(bookName, getFinalItem(*archive, entry));
   } catch(zim::EntryNotFound& e) {
-    return HTTP404Response(*this, request)
+    return HTTP404Response(request)
            + nonParameterizedMessage("random-article-failure");
   }
 }
@@ -1037,13 +1032,12 @@ std::unique_ptr<Response> InternalServer::handle_captured_external(const Request
   } catch (const std::out_of_range& e) {}
 
   if (source.empty()) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   auto data = get_default_data();
   data.set("source", source);
-  return ContentResponse::build(*this, RESOURCE::templates::captured_external_html, data, "text/html; charset=utf-8");
+  return ContentResponse::build(RESOURCE::templates::captured_external_html, data, "text/html; charset=utf-8");
 }
 
 std::unique_ptr<Response> InternalServer::handle_catch(const RequestContext& request)
@@ -1056,8 +1050,7 @@ std::unique_ptr<Response> InternalServer::handle_catch(const RequestContext& req
     return handle_captured_external(request);
   }
 
-  return HTTP404Response(*this, request)
-         + urlNotFoundMsg;
+  return UrlNotFoundResponse(request);
 }
 
 std::vector<std::string>
@@ -1117,7 +1110,7 @@ InternalServer::build_redirect(const std::string& bookName, const zim::Item& ite
 {
   const auto contentPath = "/content/" + bookName + "/" + item.getPath();
   const auto url = m_root + kiwix::urlEncode(contentPath);
-  return Response::build_redirect(*this, url);
+  return Response::build_redirect(url);
 }
 
 std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& request)
@@ -1141,15 +1134,14 @@ std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& r
 
   if (archive == nullptr) {
     const std::string searchURL = m_root + "/search?pattern=" + kiwix::urlEncode(pattern);
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg
+    return UrlNotFoundResponse(request)
            + suggestSearchMsg(searchURL, kiwix::urlDecode(pattern));
   }
 
   const std::string archiveUuid(archive->getUuid());
   const ETag etag = get_matching_if_none_match_etag(request, archiveUuid);
   if ( etag )
-    return Response::build_304(*this, etag);
+    return Response::build_304(etag);
 
   auto urlStr = url.substr(prefixLength + bookName.size());
   if (urlStr[0] == '/') {
@@ -1168,7 +1160,7 @@ std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& r
       //    '-' namespaces, in which case that resource is returned instead.
       return build_redirect(bookName, getFinalItem(*archive, entry));
     }
-    auto response = ItemResponse::build(*this, request, entry.getItem());
+    auto response = ItemResponse::build(request, entry.getItem());
     response->set_etag_body(archiveUuid);
 
     if ( !startsWith(entry.getItem().getMimetype(), "application/pdf") ) {
@@ -1189,8 +1181,7 @@ std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& r
       printf("Failed to find %s\n", urlStr.c_str());
 
     std::string searchURL = m_root + "/search?content=" + bookName + "&pattern=" + kiwix::urlEncode(pattern);
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg
+    return UrlNotFoundResponse(request)
            + suggestSearchMsg(searchURL, kiwix::urlDecode(pattern));
   }
 }
@@ -1208,13 +1199,11 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
      bookName = request.get_url_part(1);
      kind = request.get_url_part(2);
   } catch (const std::out_of_range& e) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   if (kind != "meta" && kind!= "content") {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg
+    return UrlNotFoundResponse(request)
            + invalidRawAccessMsg(kind);
   }
 
@@ -1225,15 +1214,14 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
   } catch (const std::out_of_range& e) {}
 
   if (archive == nullptr) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg
+    return UrlNotFoundResponse(request)
            + noSuchBookErrorMsg(bookName);
   }
 
   const std::string archiveUuid(archive->getUuid());
   const ETag etag = get_matching_if_none_match_etag(request, archiveUuid);
   if ( etag )
-    return Response::build_304(*this, etag);
+    return Response::build_304(etag);
 
   // Remove the beggining of the path:
   // /raw/<bookName>/<kind>/foo
@@ -1244,7 +1232,7 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
   try {
     if (kind == "meta") {
       auto item = archive->getMetadataItem(itemPath);
-      auto response = ItemResponse::build(*this, request, item);
+      auto response = ItemResponse::build(request, item);
       response->set_etag_body(archiveUuid);
       return response;
     } else {
@@ -1252,7 +1240,7 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
       if (entry.isRedirect()) {
         return build_redirect(bookName, entry.getItem(true));
       }
-      auto response = ItemResponse::build(*this, request, entry.getItem());
+      auto response = ItemResponse::build(request, entry.getItem());
       response->set_etag_body(archiveUuid);
       return response;
     }
@@ -1260,8 +1248,7 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
     if (m_verbose.load()) {
       printf("Failed to find %s\n", itemPath.c_str());
     }
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg
+    return UrlNotFoundResponse(request)
            + rawEntryNotFoundMsg(kind, itemPath);
   }
 }
@@ -1286,12 +1273,10 @@ std::unique_ptr<Response> InternalServer::handle_locally_customized_resource(con
 
   auto byteRange = request.get_range().resolve(resourceData.size());
   if (byteRange.kind() != ByteRange::RESOLVED_FULL_CONTENT) {
-    return Response::build_416(*this, resourceData.size());
+    return Response::build_416(resourceData.size());
   }
 
-  return ContentResponse::build(*this,
-                                resourceData,
-                                crd.mimeType);
+  return ContentResponse::build(resourceData, crd.mimeType);
 }
 
 }

src/server/internalServer.h

@@ -188,10 +188,6 @@ class InternalServer {
 
     class CustomizedResources;
     std::unique_ptr<CustomizedResources> m_customizedResources;
-
-    friend std::unique_ptr<Response> Response::build(const InternalServer& server);
-    friend std::unique_ptr<ContentResponse> ContentResponse::build(const InternalServer& server, const std::string& content, const std::string& mimetype);
-    friend std::unique_ptr<Response> ItemResponse::build(const InternalServer& server, const RequestContext& request, const zim::Item& item);
 };
 
 }

src/server/internalServer_catalog.cpp

@@ -63,8 +63,7 @@ std::unique_ptr<Response> InternalServer::handle_catalog(const RequestContext& r
     host = request.get_header("Host");
     url  = request.get_url_part(1);
   } catch (const std::out_of_range&) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   if (url == "v2") {
@@ -72,12 +71,11 @@ std::unique_ptr<Response> InternalServer::handle_catalog(const RequestContext& r
   }
 
   if (url != "searchdescription.xml" && url != "root.xml" && url != "search") {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   if (url == "searchdescription.xml") {
-    auto response = ContentResponse::build(*this, RESOURCE::opensearchdescription_xml, get_default_data(), "application/opensearchdescription+xml");
+    auto response = ContentResponse::build(RESOURCE::opensearchdescription_xml, get_default_data(), "application/opensearchdescription+xml");
     return std::move(response);
   }
 
@@ -95,7 +93,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog(const RequestContext& r
   }
 
   auto response = ContentResponse::build(
-      *this,
       opdsDumper.dumpOPDSFeed(bookIdsToDump, request.get_query()),
       opdsMimeType[OPDS_ACQUISITION_FEED]);
   return std::move(response);
@@ -111,15 +108,14 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2(const RequestContext
   try {
     url  = request.get_url_part(2);
   } catch (const std::out_of_range&) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   if (url == "root.xml") {
     return handle_catalog_v2_root(request);
   } else if (url == "searchdescription.xml") {
     const std::string endpoint_root = m_root + "/catalog/v2";
-    return ContentResponse::build(*this,
+    return ContentResponse::build(
         RESOURCE::catalog_v2_searchdescription_xml,
         kainjow::mustache::object({{"endpoint_root", endpoint_root}}),
         "application/opensearchdescription+xml"
@@ -138,8 +134,7 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2(const RequestContext
   } else if (url == "illustration") {
     return handle_catalog_v2_illustration(request);
   } else {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 }
 
@@ -147,7 +142,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_root(const RequestCo
 {
   const std::string libraryId = getLibraryId();
   return ContentResponse::build(
-             *this,
              RESOURCE::templates::catalog_v2_root_xml,
              kainjow::mustache::object{
                {"date", gen_date_str()},
@@ -170,7 +164,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_entries(const Reques
   const auto bookIds = search_catalog(request, opdsDumper);
   const auto opdsFeed = opdsDumper.dumpOPDSFeedV2(bookIds, request.get_query(), partial);
   return ContentResponse::build(
-             *this,
              opdsFeed,
              opdsMimeType[OPDS_ACQUISITION_FEED]
   );
@@ -181,8 +174,7 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_complete_entry(const
   try {
     mp_library->getBookById(entryId);
   } catch (const std::out_of_range&) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 
   OPDSDumper opdsDumper(mp_library.get(), mp_nameMapper.get());
@@ -190,7 +182,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_complete_entry(const
   opdsDumper.setLibraryId(getLibraryId());
   const auto opdsFeed = opdsDumper.dumpOPDSCompleteEntry(entryId);
   return ContentResponse::build(
-             *this,
              opdsFeed,
              opdsMimeType[OPDS_ENTRY]
   );
@@ -202,7 +193,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_categories(const Req
   opdsDumper.setRootLocation(m_root);
   opdsDumper.setLibraryId(getLibraryId());
   return ContentResponse::build(
-             *this,
              opdsDumper.categoriesOPDSFeed(),
              opdsMimeType[OPDS_NAVIGATION_FEED]
   );
@@ -214,7 +204,6 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_languages(const Requ
   opdsDumper.setRootLocation(m_root);
   opdsDumper.setLibraryId(getLibraryId());
   return ContentResponse::build(
-             *this,
              opdsDumper.languagesOPDSFeed(),
              opdsMimeType[OPDS_NAVIGATION_FEED]
   );
@@ -228,13 +217,11 @@ std::unique_ptr<Response> InternalServer::handle_catalog_v2_illustration(const R
     auto size = request.get_argument<unsigned int>("size");
     auto illustration = book.getIllustration(size);
     return ContentResponse::build(
-               *this,
                illustration->getData(),
                illustration->mimeType
     );
   } catch(...) {
-    return HTTP404Response(*this, request)
-           + urlNotFoundMsg;
+    return UrlNotFoundResponse(request);
   }
 }
 

src/server/request_context.cpp

@@ -51,11 +51,12 @@ RequestMethod str2RequestMethod(const std::string& method) {
 
 } // unnamed namespace
 
-RequestContext::RequestContext(struct MHD_Connection* connection,
-                               const std::string& _rootLocation, // URI-encoded
+RequestContext::RequestContext(const std::string& _rootLocation, // URI-encoded
                                const std::string& unrootedUrl,   // URI-decoded
                                const std::string& _method,
-                               const std::string& version) :
+                               const std::string& version,
+                               const NameValuePairs& headers,
+                               const NameValuePairs& queryArgs) :
   rootLocation(_rootLocation),
   url(unrootedUrl),
   method(str2RequestMethod(_method)),
@@ -64,9 +65,13 @@ RequestContext::RequestContext(struct MHD_Connection* connection,
   acceptEncodingGzip(false),
   byteRange_()
 {
-  MHD_get_connection_values(connection, MHD_HEADER_KIND, &RequestContext::fill_header, this);
-  MHD_get_connection_values(connection, MHD_GET_ARGUMENT_KIND, &RequestContext::fill_argument, this);
-  MHD_get_connection_values(connection, MHD_COOKIE_KIND, &RequestContext::fill_cookie, this);
+  for ( const auto& kv : headers ) {
+    add_header(kv.first, kv.second);
+  }
+
+  for ( const auto& kv : queryArgs ) {
+    add_argument(kv.first, kv.second);
+  }
 
   try {
     acceptEncodingGzip =
@@ -83,18 +88,14 @@ RequestContext::RequestContext(struct MHD_Connection* connection,
 RequestContext::~RequestContext()
 {}
 
-MHD_Result RequestContext::fill_header(void *__this, enum MHD_ValueKind kind,
-                                       const char *key, const char *value)
+void RequestContext::add_header(const char *key, const char *value)
 {
-  RequestContext *_this = static_cast<RequestContext*>(__this);
-  _this->headers[lcAll(key)] = value;
-  return MHD_YES;
+  this->headers[lcAll(key)] = value;
 }
 
-MHD_Result RequestContext::fill_argument(void *__this, enum MHD_ValueKind kind,
-                                         const char *key, const char* value)
+void RequestContext::add_argument(const char *key, const char* value)
 {
-  RequestContext *_this = static_cast<RequestContext*>(__this);
+  RequestContext *_this = this;
   _this->arguments[key].push_back(value == nullptr ? "" : value);
   if ( ! _this->queryString.empty() ) {
     _this->queryString += "&";
@@ -104,15 +105,6 @@ MHD_Result RequestContext::fill_argument(void *__this, enum MHD_ValueKind kind,
     _this->queryString += "=";
     _this->queryString += urlEncode(value);
   }
-  return MHD_YES;
-}
-
-MHD_Result RequestContext::fill_cookie(void *__this, enum MHD_ValueKind kind,
-                                         const char *key, const char* value)
-{
-  RequestContext *_this = static_cast<RequestContext*>(__this);
-  _this->cookies[key] = value == nullptr ? "" : value;
-  return MHD_YES;
 }
 
 void RequestContext::print_debug_info() const {

src/server/request_context.h

@@ -29,7 +29,7 @@
 #include <stdexcept>
 
 #include "byte_range.h"
-#include "tools/stringTools.h"
+#include "../tools/stringTools.h"
 
 extern "C" {
 #include "microhttpd_wrapper.h"
@@ -55,12 +55,17 @@ class IndexError: public std::runtime_error {};
 
 
 class RequestContext {
+  public: // types
+    typedef std::vector<std::pair<const char*, const char*>> NameValuePairs;
+
   public: // functions
-    RequestContext(struct MHD_Connection* connection,
-                   const std::string& rootLocation, // URI-encoded
+    RequestContext(const std::string& rootLocation, // URI-encoded
                    const std::string& unrootedUrl,  // URI-decoded
                    const std::string& method,
-                   const std::string& version);
+                   const std::string& version,
+                   const NameValuePairs& headers,
+                   const NameValuePairs& queryArgs);
+
     ~RequestContext();
 
     void print_debug_info() const;
@@ -145,16 +150,14 @@ class RequestContext {
     ByteRange byteRange_;
     std::map<std::string, std::string> headers;
     std::map<std::string, std::vector<std::string>> arguments;
-    std::map<std::string, std::string> cookies;
     std::string queryString;
     UserLanguage userlang;
 
   private: // functions
     UserLanguage determine_user_language() const;
 
-    static MHD_Result fill_header(void *, enum MHD_ValueKind, const char*, const char*);
-    static MHD_Result fill_cookie(void *, enum MHD_ValueKind, const char*, const char*);
-    static MHD_Result fill_argument(void *, enum MHD_ValueKind, const char*, const char*);
+    void add_header(const char* name, const char* value);
+    void add_argument(const char* name, const char* value);
 };
 
 template<> std::string RequestContext::get_argument(const std::string& name) const;

src/server/response.cpp

@@ -32,6 +32,9 @@
 #include <zlib.h>
 
 #include <array>
+#include <list>
+#include <map>
+#include <regex>
 
 // This is somehow a magic value.
 // If this value is too small, we will compress (and lost cpu time) too much
@@ -47,6 +50,8 @@ namespace kiwix {
 
 namespace
 {
+typedef kainjow::mustache::data MustacheData;
+
 // some utilities
 
 std::string get_mime_type(const zim::Item& item)
@@ -119,9 +124,8 @@ const char* getCacheControlHeader(Response::Kind k)
 
 } // unnamed namespace
 
-Response::Response(bool verbose)
-  : m_verbose(verbose),
-    m_returnCode(MHD_HTTP_OK)
+Response::Response()
+  : m_returnCode(MHD_HTTP_OK)
 {
   add_header(MHD_HTTP_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN, "*");
 }
@@ -133,14 +137,14 @@ void Response::set_kind(Kind k)
     m_etag.set_option(ETag::ZIM_CONTENT);
 }
 
-std::unique_ptr<Response> Response::build(const InternalServer& server)
+std::unique_ptr<Response> Response::build()
 {
-  return std::unique_ptr<Response>(new Response(server.m_verbose.load()));
+  return std::make_unique<Response>();
 }
 
-std::unique_ptr<Response> Response::build_304(const InternalServer& server, const ETag& etag)
+std::unique_ptr<Response> Response::build_304(const ETag& etag)
 {
-  auto response = Response::build(server);
+  auto response = Response::build();
   response->set_code(MHD_HTTP_NOT_MODIFIED);
   response->m_etag = etag;
   if ( etag.get_option(ETag::ZIM_CONTENT) ) {
@@ -152,67 +156,260 @@ std::unique_ptr<Response> Response::build_304(const InternalServer& server, cons
   return response;
 }
 
-const UrlNotFoundMsg urlNotFoundMsg;
-const InvalidUrlMsg invalidUrlMsg;
 
-std::string ContentResponseBlueprint::getMessage(const std::string& msgId) const
+namespace
 {
-  return getTranslatedString(m_request.get_user_language(), msgId);
+
+// This class was introduced in order to work around the missing support
+// for std::variant (and std::optional) under some of the current build
+// platforms.
+template<class T>
+class Optional
+{
+public: // functions
+    Optional() {}
+    Optional(const T& t) : ptr(new T(t)) {}
+    Optional(const Optional& o) : ptr(o.has_value() ? new T(*o) : nullptr) {}
+    Optional(Optional&& o) : ptr(std::move(o.ptr)) {}
+
+    Optional& operator=(const Optional& o)
+    {
+      *this = Optional(o);
+      return *this;
+    }
+
+    Optional& operator=(Optional&& o)
+    {
+      ptr = std::move(o.ptr);
+      return *this;
+    }
+
+    bool has_value() const { return ptr.get() != nullptr; }
+    const T& operator*() const { return *ptr; }
+    T& operator*() { return *ptr; }
+
+private: // data
+    std::unique_ptr<T> ptr;
+};
+
+} // unnamed namespace
+
+class ContentResponseBlueprint::Data
+{
+public:
+  typedef std::list<Data>             List;
+  typedef std::map<std::string, Data> Object;
+
+private:
+  // std::variant<std::string, bool, List, Object> data;
+  // XXX: libkiwix is compiled on platforms where std::variant
+  // XXX: is not yet supported. Hence this hack. Only one
+  // XXX: of the below data members is expected to contain a value.
+  Optional<std::string> m_stringValue;
+  Optional<bool>        m_boolValue;
+  Optional<List>        m_listValue;
+  Optional<Object>      m_objectValue;
+
+public:
+  Data() {}
+  Data(const std::string& s) : m_stringValue(s) {}
+  Data(bool b)               : m_boolValue(b)   {}
+  Data(const List& l)        : m_listValue(l)   {}
+  Data(const Object& o)      : m_objectValue(o) {}
+
+  MustacheData toMustache(const std::string& lang) const;
+
+  Data& operator[](const std::string& key)
+  {
+    return (*m_objectValue)[key];
+  }
+
+  void push_back(const Data& d) { (*m_listValue).push_back(d); }
+
+  static Data onlyAsNonEmptyValue(const std::string& s)
+  {
+    return s.empty() ? Data(false) : Data(s);
+  }
+
+  static Data from(const ParameterizedMessage& pmsg)
+  {
+    Object obj;
+    for(const auto& kv : pmsg.getParams()) {
+      obj[kv.first] = kv.second;
+    }
+    return Object{
+              { "msgid", pmsg.getMsgId() },
+              { "params", Data(obj) }
+    };
+  }
+
+  std::string asJSON() const;
+  void dumpJSON(std::ostream& os) const;
+
+private:
+  bool isString() const { return m_stringValue.has_value(); }
+  bool isList()   const { return m_listValue.has_value();   }
+  bool isObject() const { return m_objectValue.has_value(); }
+
+  const std::string& stringValue() const { return *m_stringValue; }
+  bool               boolValue()   const { return *m_boolValue;   }
+  const List&        listValue()   const { return *m_listValue;   }
+  const Object&      objectValue() const { return *m_objectValue; }
+
+  const Data* get(const std::string& key) const
+  {
+    if ( !isObject() )
+      return nullptr;
+
+    const auto& obj = objectValue();
+    const auto it = obj.find(key);
+    return it != obj.end() ? &it->second : nullptr;
+  }
+};
+
+MustacheData ContentResponseBlueprint::Data::toMustache(const std::string& lang) const
+{
+  if ( this->isList() ) {
+    kainjow::mustache::list l;
+    for ( const auto& x : this->listValue() ) {
+      l.push_back(x.toMustache(lang));
+    }
+    return l;
+  } else if ( this->isObject() ) {
+    const Data* msgId = this->get("msgid");
+    const Data* msgParams = this->get("params");
+    if ( msgId && msgId->isString() && msgParams && msgParams->isObject() ) {
+      std::map<std::string, std::string> params;
+      for(const auto& kv : msgParams->objectValue()) {
+        params[kv.first] = kv.second.stringValue();
+      }
+      const ParameterizedMessage msg(msgId->stringValue(), ParameterizedMessage::Parameters(params));
+      return msg.getText(lang);
+    } else {
+      kainjow::mustache::object o;
+      for ( const auto& kv : this->objectValue() ) {
+        o[kv.first] = kv.second.toMustache(lang);
+      }
+      return o;
+    }
+  } else if ( this->isString() ) {
+    return this->stringValue();
+  } else {
+    return this->boolValue();
+  }
 }
 
+void ContentResponseBlueprint::Data::dumpJSON(std::ostream& os) const
+{
+  if ( this->isString() ) {
+    os << '"' << escapeForJSON(this->stringValue()) << '"';
+  } else if ( this->isList() ) {
+    const char * sep = " ";
+    os << "[";
+
+    for ( const auto& x :  this->listValue() ) {
+      os << sep;
+      x.dumpJSON(os);
+      sep = ", ";
+    }
+    os << " ]";
+  } else if ( this->isObject() ) {
+    const char * sep = " ";
+    os << "{";
+    for ( const auto& kv : this->objectValue() ) {
+      os << sep << '"' << kv.first << "\" : ";
+      kv.second.dumpJSON(os);
+      sep = ", ";
+    }
+    os << " }";
+  } else {
+    os << (this->boolValue() ? "true" : "false");
+  }
+}
+
+std::string ContentResponseBlueprint::Data::asJSON() const
+{
+  std::ostringstream oss;
+  this->dumpJSON(oss);
+
+  // This JSON is going to be used in HTML inside a <script></script> tag.
+  // If it contains "</script>" (or "</script >") as a substring, then the HTML
+  // parser will be confused. Since for a valid JSON that may happen only inside
+  // a JSON string, we can safely take advantage of the answers to
+  // https://stackoverflow.com/questions/28259389/how-to-put-script-in-a-javascript-string
+  // and work around the issue by inserting an otherwise harmless backslash.
+  return std::regex_replace(oss.str(), std::regex("</script"), "</scr\\ipt");
+}
+
+ContentResponseBlueprint::ContentResponseBlueprint(const RequestContext* request,
+                         int httpStatusCode,
+                         const std::string& mimeType,
+                         const std::string& templateStr,
+                         bool includeKiwixResponseData)
+  : m_request(*request)
+  , m_httpStatusCode(httpStatusCode)
+  , m_mimeType(mimeType)
+  , m_template(templateStr)
+  , m_includeKiwixResponseData(includeKiwixResponseData)
+  , m_data(new Data)
+{}
+
+ContentResponseBlueprint::~ContentResponseBlueprint() = default;
+
 std::unique_ptr<ContentResponse> ContentResponseBlueprint::generateResponseObject() const
 {
-  auto r = ContentResponse::build(m_server, m_template, m_data, m_mimeType);
+  kainjow::mustache::data d = m_data->toMustache(m_request.get_user_language());
+  if ( m_includeKiwixResponseData ) {
+    d.set("KIWIX_RESPONSE_TEMPLATE", escapeForJSON(m_template, false));
+    d.set("KIWIX_RESPONSE_DATA", m_data->asJSON());
+  }
+  auto r = ContentResponse::build(m_template, d, m_mimeType);
   r->set_code(m_httpStatusCode);
   return r;
 }
 
-HTTPErrorResponse::HTTPErrorResponse(const InternalServer& server,
-                                     const RequestContext& request,
+HTTPErrorResponse::HTTPErrorResponse(const RequestContext& request,
                                      int httpStatusCode,
                                      const std::string& pageTitleMsgId,
                                      const std::string& headingMsgId,
-                                     const std::string& cssUrl)
-  : ContentResponseBlueprint(&server,
-                             &request,
+                                     const std::string& cssUrl,
+                                     bool includeKiwixResponseData)
+  : ContentResponseBlueprint(&request,
                              httpStatusCode,
                              request.get_requested_format() == "html" ? "text/html; charset=utf-8" : "application/xml; charset=utf-8",
-                             request.get_requested_format() == "html" ? RESOURCE::templates::error_html : RESOURCE::templates::error_xml)
+                             request.get_requested_format() == "html" ? RESOURCE::templates::error_html : RESOURCE::templates::error_xml,
+                             includeKiwixResponseData)
 {
-  kainjow::mustache::list emptyList;
-  this->m_data = kainjow::mustache::object{
-                    {"CSS_URL", onlyAsNonEmptyMustacheValue(cssUrl) },
-                    {"PAGE_TITLE",   getMessage(pageTitleMsgId)},
-                    {"PAGE_HEADING", getMessage(headingMsgId)},
+  Data::List emptyList;
+  *this->m_data = Data(Data::Object{
+                    {"CSS_URL", Data::onlyAsNonEmptyValue(cssUrl) },
+                    {"PAGE_TITLE",   Data::from(nonParameterizedMessage(pageTitleMsgId))},
+                    {"PAGE_HEADING", Data::from(nonParameterizedMessage(headingMsgId))},
                     {"details", emptyList}
-  };
+  });
 }
 
-HTTP404Response::HTTP404Response(const InternalServer& server,
-                                 const RequestContext& request)
-  : HTTPErrorResponse(server,
-                      request,
+HTTP404Response::HTTP404Response(const RequestContext& request)
+  : HTTPErrorResponse(request,
                       MHD_HTTP_NOT_FOUND,
                       "404-page-title",
-                      "404-page-heading")
+                      "404-page-heading",
+                      std::string(),
+                      /*includeKiwixResponseData=*/true)
 {
 }
 
-HTTPErrorResponse& HTTP404Response::operator+(UrlNotFoundMsg /*unused*/)
+UrlNotFoundResponse::UrlNotFoundResponse(const RequestContext& request)
+    : HTTP404Response(request)
 {
   const std::string requestUrl = urlDecode(m_request.get_full_url(), false);
-  return *this + ParameterizedMessage("url-not-found", {{"url", requestUrl}});
-}
-
-HTTPErrorResponse& HTTPErrorResponse::operator+(const std::string& msg)
-{
-  m_data["details"].push_back({"p", msg});
-  return *this;
+  *this += ParameterizedMessage("url-not-found", {{"url", requestUrl}});
 }
 
 HTTPErrorResponse& HTTPErrorResponse::operator+(const ParameterizedMessage& details)
 {
-  return *this + details.getText(m_request.get_user_language());
+  (*m_data)["details"].push_back(Data::Object{{"p", Data::from(details)}});
+  return *this;
 }
 
 HTTPErrorResponse& HTTPErrorResponse::operator+=(const ParameterizedMessage& details)
@@ -222,50 +419,36 @@ HTTPErrorResponse& HTTPErrorResponse::operator+=(const ParameterizedMessage& det
 }
 
 
-HTTP400Response::HTTP400Response(const InternalServer& server,
-                                 const RequestContext& request)
-  : HTTPErrorResponse(server,
-                      request,
+HTTP400Response::HTTP400Response(const RequestContext& request)
+  : HTTPErrorResponse(request,
                       MHD_HTTP_BAD_REQUEST,
                       "400-page-title",
-                      "400-page-heading")
-{
-}
-
-HTTPErrorResponse& HTTP400Response::operator+(InvalidUrlMsg /*unused*/)
+                      "400-page-heading",
+                      std::string(),
+                      /*includeKiwixResponseData=*/true)
 {
   std::string requestUrl = urlDecode(m_request.get_full_url(), false);
   const auto query = m_request.get_query();
   if (!query.empty()) {
     requestUrl += "?" + encodeDiples(query);
   }
-  kainjow::mustache::mustache msgTmpl(R"(The requested URL "{{{url}}}" is not a valid request.)");
-  return *this + msgTmpl.render({"url", requestUrl});
+  *this += ParameterizedMessage("invalid-request", {{"url", requestUrl}});
 }
 
-HTTP500Response::HTTP500Response(const InternalServer& server,
-                                 const RequestContext& request)
-  : HTTPErrorResponse(server,
-                      request,
+HTTP500Response::HTTP500Response(const RequestContext& request)
+  : HTTPErrorResponse(request,
                       MHD_HTTP_INTERNAL_SERVER_ERROR,
                       "500-page-title",
-                      "500-page-heading")
+                      "500-page-heading",
+                      std::string(),
+                      /*includeKiwixResponseData=*/true)
 {
-  // operator+() is a state-modifying operator (akin to operator+=)
-  *this + "An internal server error occured. We are sorry about that :/";
+  *this += nonParameterizedMessage("500-page-text");
 }
 
-std::unique_ptr<ContentResponse> HTTP500Response::generateResponseObject() const
+std::unique_ptr<Response> Response::build_416(size_t resourceLength)
 {
-  const std::string mimeType = "text/html;charset=utf-8";
-  auto r = ContentResponse::build(m_server, m_template, m_data, mimeType);
-  r->set_code(m_httpStatusCode);
-  return r;
-}
-
-std::unique_ptr<Response> Response::build_416(const InternalServer& server, size_t resourceLength)
-{
-  auto response = Response::build(server);
+  auto response = Response::build();
 // [FIXME] (compile with recent enough version of libmicrohttpd)
 //  response->set_code(MHD_HTTP_RANGE_NOT_SATISFIABLE);
   response->set_code(416);
@@ -277,9 +460,9 @@ std::unique_ptr<Response> Response::build_416(const InternalServer& server, size
 }
 
 
-std::unique_ptr<Response> Response::build_redirect(const InternalServer& server, const std::string& redirectUrl)
+std::unique_ptr<Response> Response::build_redirect(const std::string& redirectUrl)
 {
-  auto response = Response::build(server);
+  auto response = Response::build();
   response->m_returnCode = MHD_HTTP_FOUND;
   response->add_header(MHD_HTTP_HEADER_LOCATION, redirectUrl);
   return response;
@@ -374,7 +557,7 @@ ContentResponse::create_mhd_response(const RequestContext& request)
   return response;
 }
 
-MHD_Result Response::send(const RequestContext& request, MHD_Connection* connection)
+MHD_Result Response::send(const RequestContext& request, bool verbose, MHD_Connection* connection)
 {
   MHD_Response* response = create_mhd_response(request);
 
@@ -390,7 +573,7 @@ MHD_Result Response::send(const RequestContext& request, MHD_Connection* connect
   if (m_returnCode == MHD_HTTP_OK && m_byteRange.kind() == ByteRange::RESOLVED_PARTIAL_CONTENT)
     m_returnCode = MHD_HTTP_PARTIAL_CONTENT;
 
-  if (m_verbose)
+  if (verbose)
     print_response_info(m_returnCode, response);
 
   auto ret = MHD_queue_response(connection, m_returnCode, response);
@@ -398,9 +581,8 @@ MHD_Result Response::send(const RequestContext& request, MHD_Connection* connect
   return ret;
 }
 
-ContentResponse::ContentResponse(const std::string& root, bool verbose, const std::string& content, const std::string& mimetype) :
-  Response(verbose),
-  m_root(root),
+ContentResponse::ContentResponse(const std::string& content, const std::string& mimetype) :
+  Response(),
   m_content(content),
   m_mimeType(mimetype)
 {
@@ -408,29 +590,23 @@ ContentResponse::ContentResponse(const std::string& root, bool verbose, const st
 }
 
 std::unique_ptr<ContentResponse> ContentResponse::build(
-  const InternalServer& server,
   const std::string& content,
   const std::string& mimetype)
 {
-   return std::unique_ptr<ContentResponse>(new ContentResponse(
-        server.m_root,
-        server.m_verbose.load(),
-        content,
-        mimetype));
+   return std::make_unique<ContentResponse>(content, mimetype);
 }
 
 std::unique_ptr<ContentResponse> ContentResponse::build(
-  const InternalServer& server,
   const std::string& template_str,
   kainjow::mustache::data data,
   const std::string& mimetype)
 {
   auto content = render_template(template_str, data);
-  return ContentResponse::build(server, content, mimetype);
+  return ContentResponse::build(content, mimetype);
 }
 
-ItemResponse::ItemResponse(bool verbose, const zim::Item& item, const std::string& mimetype, const ByteRange& byterange) :
-  Response(verbose),
+ItemResponse::ItemResponse(const zim::Item& item, const std::string& mimetype, const ByteRange& byterange) :
+  Response(),
   m_item(item),
   m_mimeType(mimetype)
 {
@@ -439,30 +615,26 @@ ItemResponse::ItemResponse(bool verbose, const zim::Item& item, const std::strin
   add_header(MHD_HTTP_HEADER_CONTENT_TYPE, m_mimeType);
 }
 
-std::unique_ptr<Response> ItemResponse::build(const InternalServer& server, const RequestContext& request, const zim::Item& item)
+std::unique_ptr<Response> ItemResponse::build(const RequestContext& request, const zim::Item& item)
 {
   const std::string mimetype = get_mime_type(item);
   auto byteRange = request.get_range().resolve(item.getSize());
   const bool noRange = byteRange.kind() == ByteRange::RESOLVED_FULL_CONTENT;
   if (noRange && is_compressible_mime_type(mimetype)) {
     // Return a contentResponse
-    auto response = ContentResponse::build(server, item.getData(), mimetype);
+    auto response = ContentResponse::build(item.getData(), mimetype);
     response->set_kind(Response::ZIM_CONTENT);
     response->m_byteRange = byteRange;
     return std::move(response);
   }
 
   if (byteRange.kind() == ByteRange::RESOLVED_UNSATISFIABLE) {
-    auto response = Response::build_416(server, item.getSize());
+    auto response = Response::build_416(item.getSize());
     response->set_kind(Response::ZIM_CONTENT);
     return response;
   }
 
-  return std::unique_ptr<Response>(new ItemResponse(
-        server.m_verbose.load(),
-        item,
-        mimetype,
-        byteRange));
+  return std::make_unique<ItemResponse>(item, mimetype, byteRange);
 }
 
 MHD_Response*

src/server/response.h

@@ -41,7 +41,6 @@ class Archive;
 
 namespace kiwix {
 
-class InternalServer;
 class RequestContext;
 
 class Response {
@@ -54,15 +53,15 @@ class Response {
     };
 
   public:
-    Response(bool verbose);
+    Response();
     virtual ~Response() = default;
 
-    static std::unique_ptr<Response> build(const InternalServer& server);
-    static std::unique_ptr<Response> build_304(const InternalServer& server, const ETag& etag);
-    static std::unique_ptr<Response> build_416(const InternalServer& server, size_t resourceLength);
-    static std::unique_ptr<Response> build_redirect(const InternalServer& server, const std::string& redirectUrl);
+    static std::unique_ptr<Response> build();
+    static std::unique_ptr<Response> build_304(const ETag& etag);
+    static std::unique_ptr<Response> build_416(size_t resourceLength);
+    static std::unique_ptr<Response> build_redirect(const std::string& redirectUrl);
 
-    MHD_Result send(const RequestContext& request, MHD_Connection* connection);
+    MHD_Result send(const RequestContext& request, bool verbose, MHD_Connection* connection);
 
     void set_code(int code) { m_returnCode = code; }
     void set_kind(Kind k);
@@ -78,7 +77,6 @@ class Response {
 
   protected: // data
     Kind m_kind = DYNAMIC_CONTENT;
-    bool m_verbose;
     int m_returnCode;
     ByteRange m_byteRange;
     ETag m_etag;
@@ -91,22 +89,21 @@ class Response {
 class ContentResponse : public Response {
   public:
     ContentResponse(
-      const std::string& root,
-      bool verbose,
       const std::string& content,
       const std::string& mimetype);
 
     static std::unique_ptr<ContentResponse> build(
-      const InternalServer& server,
       const std::string& content,
       const std::string& mimetype);
 
     static std::unique_ptr<ContentResponse> build(
-      const InternalServer& server,
       const std::string& template_str,
       kainjow::mustache::data data,
       const std::string& mimetype);
 
+    const std::string& getContent() const { return m_content; }
+    const std::string& getMimeType() const { return m_mimeType; }
+
   private:
     MHD_Response* create_mhd_response(const RequestContext& request);
 
@@ -114,7 +111,6 @@ class ContentResponse : public Response {
 
 
   private:
-    std::string m_root;
     std::string m_content;
     std::string m_mimeType;
  };
@@ -122,99 +118,70 @@ class ContentResponse : public Response {
 class ContentResponseBlueprint
 {
 public: // functions
-  ContentResponseBlueprint(const InternalServer* server,
-                           const RequestContext* request,
+  ContentResponseBlueprint(const RequestContext* request,
                            int httpStatusCode,
                            const std::string& mimeType,
-                           const std::string& templateStr)
-    : m_server(*server)
-    , m_request(*request)
-    , m_httpStatusCode(httpStatusCode)
-    , m_mimeType(mimeType)
-    , m_template(templateStr)
-  {}
+                           const std::string& templateStr,
+                           bool includeKiwixResponseData = false);
 
-  virtual ~ContentResponseBlueprint() = default;
+  ~ContentResponseBlueprint();
 
-  operator std::unique_ptr<ContentResponse>() const
+  operator std::unique_ptr<Response>() const
   {
     return generateResponseObject();
   }
 
-  operator std::unique_ptr<Response>() const
-  {
-    return operator std::unique_ptr<ContentResponse>();
-  }
+  std::unique_ptr<ContentResponse> generateResponseObject() const;
 
+protected: // types
+  class Data;
 
-protected: // functions
-  std::string getMessage(const std::string& msgId) const;
-  virtual std::unique_ptr<ContentResponse> generateResponseObject() const;
-
-public: //data
-  const InternalServer& m_server;
+protected: //data
   const RequestContext& m_request;
   const int m_httpStatusCode;
   const std::string m_mimeType;
   const std::string m_template;
-  kainjow::mustache::data m_data;
+  const bool m_includeKiwixResponseData;
+  std::unique_ptr<Data> m_data;
 };
 
 struct HTTPErrorResponse : ContentResponseBlueprint
 {
-  HTTPErrorResponse(const InternalServer& server,
-                    const RequestContext& request,
+  HTTPErrorResponse(const RequestContext& request,
                     int httpStatusCode,
                     const std::string& pageTitleMsgId,
                     const std::string& headingMsgId,
-                    const std::string& cssUrl = "");
+                    const std::string& cssUrl = "",
+                    bool includeKiwixResponseData = false);
 
-  HTTPErrorResponse& operator+(const std::string& msg);
   HTTPErrorResponse& operator+(const ParameterizedMessage& errorDetails);
   HTTPErrorResponse& operator+=(const ParameterizedMessage& errorDetails);
 };
 
-class UrlNotFoundMsg {};
-
-extern const UrlNotFoundMsg urlNotFoundMsg;
-
 struct HTTP404Response : HTTPErrorResponse
 {
-  HTTP404Response(const InternalServer& server,
-                  const RequestContext& request);
-
-  using HTTPErrorResponse::operator+;
-  HTTPErrorResponse& operator+(UrlNotFoundMsg /*unused*/);
+  explicit HTTP404Response(const RequestContext& request);
 };
 
-class InvalidUrlMsg {};
-
-extern const InvalidUrlMsg invalidUrlMsg;
+struct UrlNotFoundResponse : HTTP404Response
+{
+  explicit UrlNotFoundResponse(const RequestContext& request);
+};
 
 struct HTTP400Response : HTTPErrorResponse
 {
-  HTTP400Response(const InternalServer& server,
-                  const RequestContext& request);
-
-  using HTTPErrorResponse::operator+;
-  HTTPErrorResponse& operator+(InvalidUrlMsg /*unused*/);
+  explicit HTTP400Response(const RequestContext& request);
 };
 
 struct HTTP500Response : HTTPErrorResponse
 {
-  HTTP500Response(const InternalServer& server,
-                  const RequestContext& request);
-
-private: // overrides
-  // generateResponseObject() is overriden in order to produce a minimal
-  // response without any need for additional resources from the server
-  std::unique_ptr<ContentResponse> generateResponseObject() const override;
+  explicit HTTP500Response(const RequestContext& request);
 };
 
 class ItemResponse : public Response {
   public:
-    ItemResponse(bool verbose, const zim::Item& item, const std::string& mimetype, const ByteRange& byterange);
-    static std::unique_ptr<Response> build(const InternalServer& server, const RequestContext& request, const zim::Item& item);
+    ItemResponse(const zim::Item& item, const std::string& mimetype, const ByteRange& byterange);
+    static std::unique_ptr<Response> build(const RequestContext& request, const zim::Item& item);
 
   private:
     MHD_Response* create_mhd_response(const RequestContext& request);

src/tools/networkTools.cpp

@@ -43,6 +43,10 @@
 #include <netdb.h>
 #endif
 
+#ifdef __HAIKU__
+#include <sys/sockio.h>
+#endif
+
 size_t write_callback_to_iss(char* ptr, size_t size, size_t nmemb, void* userdata)
 {
   auto str = static_cast<std::stringstream*>(userdata);

src/tools/otherTools.cpp

@@ -327,17 +327,27 @@ std::string kiwix::render_template(const std::string& template_str, kainjow::mus
   return ss.str();
 }
 
-namespace
-{
+// The escapeQuote parameter of escapeForJSON() defaults to true.
+// This constant makes the calls to escapeForJSON() where the quote symbol
+// should not be escaped (as it is later replaced with the HTML character entity
+// ") more readable.
+static const bool DONT_ESCAPE_QUOTE = false;
 
-std::string escapeForJSON(const std::string& s)
+std::string kiwix::escapeForJSON(const std::string& s, bool escapeQuote)
 {
   std::ostringstream oss;
   for (char c : s) {
     if ( c == '\\' ) {
       oss << "\\\\";
     } else if ( unsigned(c) < 0x20U ) {
-      oss << "\\u" << std::setw(4) << std::setfill('0') << unsigned(c);
+      switch ( c ) {
+      case '\n': oss << "\\n"; break;
+      case '\r': oss << "\\r"; break;
+      case '\t': oss << "\\t"; break;
+      default:   oss << "\\u" << std::setw(4) << std::setfill('0') << unsigned(c);
+      }
+    } else if ( c == '"' && escapeQuote ) {
+      oss << "\\\"";
     } else {
       oss << c;
     }
@@ -345,6 +355,9 @@ std::string escapeForJSON(const std::string& s)
   return oss.str();
 }
 
+namespace
+{
+
 std::string makeFulltextSearchSuggestion(const std::string& lang,
                                          const std::string& queryString)
 {
@@ -370,10 +383,10 @@ void kiwix::Suggestions::add(const zim::SuggestionItem& suggestion)
                           ? suggestion.getSnippet()
                           : suggestion.getTitle();
 
-  result.set("label", escapeForJSON(label));
-  result.set("value", escapeForJSON(suggestion.getTitle()));
+  result.set("label", escapeForJSON(label, DONT_ESCAPE_QUOTE));
+  result.set("value", escapeForJSON(suggestion.getTitle(), DONT_ESCAPE_QUOTE));
   result.set("kind", "path");
-  result.set("path", escapeForJSON(suggestion.getPath()));
+  result.set("path", escapeForJSON(suggestion.getPath(), DONT_ESCAPE_QUOTE));
   result.set("first", m_data.is_empty_list());
   m_data.push_back(result);
 }
@@ -383,8 +396,8 @@ void kiwix::Suggestions::addFTSearchSuggestion(const std::string& uiLang,
 {
   kainjow::mustache::data result;
   const std::string label = makeFulltextSearchSuggestion(uiLang, queryString);
-  result.set("label", escapeForJSON(label));
-  result.set("value", escapeForJSON(queryString + " "));
+  result.set("label", escapeForJSON(label, DONT_ESCAPE_QUOTE));
+  result.set("value", escapeForJSON(queryString + " ", DONT_ESCAPE_QUOTE));
   result.set("kind", "pattern");
   result.set("first", m_data.is_empty_list());
   m_data.push_back(result);

src/tools/stringTools.h

@@ -53,6 +53,7 @@ private:
   const icu::Locale locale;
 };
 
+std::string escapeForJSON(const std::string& s, bool escapeQuote = true);
 
 /* urlEncode() is the equivalent of JS encodeURIComponent(), with the only
  * difference that the slash (/) symbol is NOT encoded. */

static/generate_i18n_resources_list.py

@@ -30,7 +30,10 @@ def get_translation_info(filepath):
     with open(filepath, 'r', encoding="utf-8") as f:
         content = json.load(f)
         lang_name = content.get("name")
-        return lang_code, lang_name
+        translation_count = len(content)
+        return dict(iso_code=lang_code,
+                    self_name=lang_name,
+                    translation_count=translation_count)
 
 language_list = []
 json_files = translation_dir.glob("*.json")
@@ -40,14 +43,14 @@ with open(resource_file, 'w', encoding="utf-8") as f:
             continue
         print("Processing", i18n_file.name)
         if i18n_file.name != "test.json":
-            lang_code, lang_name = get_translation_info(i18n_file)
+            translation_info = get_translation_info(i18n_file)
+            lang_name = translation_info["self_name"]
             if lang_name:
-                language_list.append((lang_code, lang_name))
+                language_list.append(translation_info)
             else:
                 print(f"Warning: missing 'name' in {i18n_file.name}")
         f.write(str(i18n_file.relative_to(script_path.parent)) + '\n')
 
-language_list = [{name: code} for code, name in sorted(language_list)]
 language_list_jsobj_str = json.dumps(language_list,
                                      indent=2,
                                      ensure_ascii=False)

static/skin/i18n.js

@@ -69,15 +69,66 @@ function $t(msgId, params={}) {
   }
 }
 
+const I18n = {
+  instantiateParameterizedMessages: function(data) {
+    if ( data.__proto__ == Array.prototype ) {
+      const result = [];
+      for ( const x of data ) {
+        result.push(this.instantiateParameterizedMessages(x));
+      }
+      return result;
+    } else if ( data.__proto__ == Object.prototype ) {
+      const msgId = data.msgid;
+      const msgParams = data.params;
+      if ( msgId && msgId.__proto__ == String.prototype && msgParams && msgParams.__proto__ == Object.prototype ) {
+        return $t(msgId, msgParams);
+      } else {
+        const result = {};
+        for ( const p in data ) {
+          result[p] = this.instantiateParameterizedMessages(data[p]);
+        }
+        return result;
+      }
+    } else {
+      return data;
+    }
+  },
+
+  render: function (template, params) {
+    params = this.instantiateParameterizedMessages(params);
+    return mustache.render(template, params);
+  }
+}
+
 const DEFAULT_UI_LANGUAGE = 'en';
 
 Translations.load(DEFAULT_UI_LANGUAGE, /*asDefault=*/true);
 
+// Below function selects the most suitable UI language from the list
+// of preferred languages in browser preferences and available translations.
+// Since, unlike Accept-Language header, navigator.languages doesn't contain
+// qvalues, they are computed using the same algorithm as in Firefox 121
+function getDefaultUserLanguage() {
+  const mostSuitableLang = { code: DEFAULT_UI_LANGUAGE, score: 0 }
+  const n = navigator.languages.length;
+  for (const lang of uiLanguages ) {
+    const rank = navigator.languages.indexOf(lang.iso_code);
+    if ( rank >= 0 ) {
+      const qvalue = Math.round(10*(1 - rank/n))/10;
+      const score = qvalue * lang.translation_count;
+      if ( score > mostSuitableLang.score ) {
+        mostSuitableLang.code = lang.iso_code;
+        mostSuitableLang.score = score;
+      }
+    }
+  }
+  return mostSuitableLang.code;
+}
+
 function getUserLanguage() {
   return new URLSearchParams(window.location.search).get('userlang')
       || window.localStorage.getItem('userlang')
-      || viewerSettings.defaultUserLanguage
-      || DEFAULT_UI_LANGUAGE;
+      || getDefaultUserLanguage();
 }
 
 function setUserLanguage(lang, callback) {
@@ -133,10 +184,8 @@ function initUILanguageSelector(activeLanguage, languageChangeCallback) {
   }
   const languageSelector = document.getElementById("ui_language");
   for (const lang of uiLanguages ) {
-    const lang_name = Object.getOwnPropertyNames(lang)[0];
-    const lang_code = lang[lang_name];
-    const is_selected = lang_code == activeLanguage;
-    languageSelector.appendChild(new Option(lang_name, lang_code, is_selected, is_selected));
+    const is_selected = lang.iso_code == activeLanguage;
+    languageSelector.appendChild(new Option(lang.self_name, lang.iso_code, is_selected, is_selected));
   }
   languageSelector.onchange = languageChangeCallback;
 }
@@ -145,3 +194,4 @@ window.$t = $t;
 window.getUserLanguage = getUserLanguage;
 window.setUserLanguage = setUserLanguage;
 window.initUILanguageSelector = initUILanguageSelector;
+window.I18n = I18n;

static/skin/i18n/en.json

@@ -12,6 +12,7 @@
 	, "suggest-search" : "Make a full text search for <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>"
 	, "random-article-failure" :  "Oops! Failed to pick a random article :("
 	, "invalid-raw-data-type" : "{{DATATYPE}} is not a valid request for raw content."
+	, "invalid-request" : "The requested URL \"{{{url}}}\" is not a valid request."
 	, "no-value-for-arg": "No value provided for argument {{ARGUMENT}}"
 	, "no-query" : "No query provided."
 	, "raw-entry-not-found" : "Cannot find {{DATATYPE}} entry {{ENTRY}}"
@@ -21,8 +22,14 @@
 	, "404-page-heading" : "Not Found"
 	, "500-page-title" : "Internal Server Error"
 	, "500-page-heading" : "Internal Server Error"
+	, "500-page-text": "An internal server error occured. We are sorry about that :/"
 	, "fulltext-search-unavailable" : "Fulltext search unavailable"
 	, "no-search-results": "The fulltext search engine is not available for this content."
+	, "search-results-page-title": "Search: {{SEARCH_PATTERN}}"
+	, "search-results-page-header": "Results <b>{{START}}-{{END}}</b> of <b>{{COUNT}}</b> for <b>\"{{{SEARCH_PATTERN}}}\"</b>"
+	, "empty-search-results-page-header": "No results were found for <b>\"{{{SEARCH_PATTERN}}}\"</b>"
+	, "search-result-book-info": "from {{BOOK_TITLE}}"
+	, "word-count": "{{COUNT}} words"
 	, "library-button-text": "Go to welcome page"
 	, "home-button-text": "Go to the main page of '{{BOOK_TITLE}}'"
 	, "random-page-button-text": "Go to a randomly selected page"
@@ -51,4 +58,6 @@
 	, "download-links-heading": "Download links for <b><i>{{BOOK_TITLE}}</i></b>"
 	, "download-links-title": "Download book"
 	, "preview-book": "Preview"
+	, "non-translated-text": "{{MSG}}"
+	, "unknown-error": "Unknown error"
 }

static/skin/i18n/fr.json

@@ -4,7 +4,9 @@
 			"Gomoko",
 			"Stephane",
 			"Thibaut120094",
-			"Verdy p"
+			"Verdy p",
+			"Vikoula5",
+			"Wladek92"
 		]
 	},
 	"name": "Français",
@@ -16,6 +18,7 @@
 	"suggest-search": "Faire une recherche en texte intégral de « <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a> »",
 	"random-article-failure": "Oups ! Échec de sélection d’un article aléatoire :(",
 	"invalid-raw-data-type": "{{DATATYPE}} n’est pas une requête valide pour du contenu brut.",
+	"invalid-request": "L'URL demandée \"{{{url}}}\" n'est pas une requête valide.",
 	"no-value-for-arg": "Aucune valeur fournie pour l’argument {{ARGUMENT}}",
 	"no-query": "Aucune requête fournie.",
 	"raw-entry-not-found": "Impossible de trouver l’entrée « {{ENTRY}} » de type « {{DATATYPE}} »",
@@ -25,6 +28,7 @@
 	"404-page-heading": "Non trouvé",
 	"500-page-title": "Erreur interne du serveur",
 	"500-page-heading": "Erreur interne du serveur",
+	"500-page-text": "Une erreur de serveur interne s'est produite. Nous en sommes désolés :/",
 	"fulltext-search-unavailable": "Recherche en texte intégral non disponible",
 	"no-search-results": "Le moteur de recherche en texte intégral n’est pas disponible pour ce contenu.",
 	"library-button-text": "Aller à la page de bienvenue",
@@ -54,5 +58,6 @@
 	"welcome-to-kiwix-server": "Bienvenue sur le Serveur Kiwix",
 	"download-links-heading": "Liens de téléchargement pour <b><i>{{BOOK_TITLE}}</i></b>",
 	"download-links-title": "Télécharger le livre",
-	"preview-book": "Aperçu"
+	"preview-book": "Aperçu",
+	"unknown-error": "Erreur inconnue"
 }

static/skin/i18n/he.json

@@ -14,6 +14,7 @@
 	"suggest-search": "לעשות חיפוש טקסט מלא עבור <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>",
 	"random-article-failure": "אוי! לא עבדה בחירת ערך אקראי :(",
 	"invalid-raw-data-type": "{{DATATYPE}} הוא לא בקשה תקינה של תוכן גולמי.",
+	"invalid-request": "הכתובת המבוקשת \"{{{url}}}\" אינה בקשה תקינה.",
 	"no-value-for-arg": "לא סופק ערך לארגומנט {{ARGUMENT}}",
 	"no-query": "לא סופקה שאילתה.",
 	"raw-entry-not-found": "לא ניתן למצוא את רשומת ה־{{DATATYPE}} בשם {{ENTRY}}",
@@ -23,6 +24,7 @@
 	"404-page-heading": "לא נמצא",
 	"500-page-title": "שגיאת שרת פנימית",
 	"500-page-heading": "שגיאת שרת פנימית",
+	"500-page-text": "אירעה שגיאת שרת פנימית. אנחנו מצטערים על זה :/",
 	"fulltext-search-unavailable": "חיפוש בטקסט מלא אינו זמין",
 	"no-search-results": "מנוע החיפוש בטקסט מלא אינו זמין עבור התוכן הזה.",
 	"library-button-text": "מעבר לדף הבית \"ברוך בואך\"",
@@ -52,5 +54,6 @@
 	"welcome-to-kiwix-server": "ברוך בואך לשרת קיוויקס",
 	"download-links-heading": "הורדת קישורים עבור <b><i>{{BOOK_TITLE}}</i></b>",
 	"download-links-title": "הורדת ספר",
-	"preview-book": "תצוגה מקדימה"
+	"preview-book": "תצוגה מקדימה",
+	"unknown-error": "שגיאה בלתי־ידועה"
 }

static/skin/i18n/it.json

@@ -3,6 +3,7 @@
 		"authors": [
 			"Albano",
 			"Beta16",
+			"Luca.favorido",
 			"McDutchie"
 		]
 	},
@@ -14,6 +15,7 @@
 	"url-not-found": "L'URL richiesto \"{{url}}\" non è stato trovato in questo server.",
 	"suggest-search": "Effettua una ricerca di testo completo per <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>",
 	"random-article-failure": "Ops! Impossibile selezionare un articolo casuale :(",
+	"invalid-request": "L'URL richiesto \"{{{url}}}\" non è una richiesta valida.",
 	"no-value-for-arg": "Nessun valore fornito per l'argomento {{ARGUMENT}}",
 	"400-page-title": "Richiesta non valida",
 	"400-page-heading": "Richiesta non valida",
@@ -21,6 +23,7 @@
 	"404-page-heading": "Non trovato",
 	"500-page-title": "Errore interno del server",
 	"500-page-heading": "Errore interno del server",
+	"500-page-text": "Si è verificato un errore interno del server. Ci dispiace :/",
 	"library-button-text": "Vai alla pagina di benvenuto",
 	"home-button-text": "Vai alla pagina principale di '{{BOOK_TITLE}}'",
 	"random-page-button-text": "Vai a una pagina selezionata casualmente",
@@ -30,5 +33,6 @@
 	"count-of-matching-books": "{{COUNT}} libro/i",
 	"download": "Scarica",
 	"download-links-title": "Scarica libro",
-	"preview-book": "Anteprima"
+	"preview-book": "Anteprima",
+	"unknown-error": "Errore sconosciuto"
 }

static/skin/i18n/lb.json

@@ -13,6 +13,7 @@
 	"404-page-heading": "Net fonnt",
 	"500-page-title": "Interne Feeler um Server",
 	"500-page-heading": "Interne Feeler um Server",
+	"500-page-text": "Et ass en interne Serverfeeler opgetrueden. Mir entschëllegen eis dofir :/",
 	"fulltext-search-unavailable": "Volltext-Sich net verfügbar",
 	"home-button-text": "Gitt op d'Haaptsäit vun '{{BOOK_TITLE}}'",
 	"random-page-button-text": "Gitt op eng zoufälleg gewielte Säit",
@@ -24,5 +25,6 @@
 	"count-of-matching-books": "{{COUNT}} Buch/Bicher",
 	"download": "Eroflueden",
 	"direct-download-link-text": "Direkt",
-	"download-links-title": "Buch eroflueden"
+	"download-links-title": "Buch eroflueden",
+	"unknown-error": "Onbekannte Feeler"
 }

static/skin/i18n/mk.json

@@ -14,6 +14,7 @@
 	"suggest-search": "Побарајте го <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a> по целиот текст",
 	"random-article-failure": "Упс! Не успеав да изберам случајна статија :(",
 	"invalid-raw-data-type": "{{DATATYPE}} не претставува важечко барање за сирова содржина.",
+	"invalid-request": "Побараната URL „{{{url}}}“ не претставува важечко барање.",
 	"no-value-for-arg": "Нема укажано вредност за аргументот {{ARGUMENT}}",
 	"no-query": "Не е укажано барање.",
 	"raw-entry-not-found": "Не можам да ја најдам {{DATATYPE}}-ставката {{ENTRY}}",
@@ -23,6 +24,7 @@
 	"404-page-heading": "Не е најдено",
 	"500-page-title": "Внатрешна грешка во опслужувачот",
 	"500-page-heading": "Внатрешна грешка во опслужувачот",
+	"500-page-text": "Настана внатрешна грешка во опслужувачот. Жал ни е :/",
 	"fulltext-search-unavailable": "Целотекстното пребарување е недостапно",
 	"no-search-results": "Погонот за целотекстно пребарување не е достапен за оваа содржина.",
 	"library-button-text": "Оди на воведната страница",
@@ -52,5 +54,6 @@
 	"welcome-to-kiwix-server": "Добре дојдовте на Опслужувачот на Кивикс",
 	"download-links-heading": "Врски за преземање на <b><i>{{BOOK_TITLE}}</i></b>",
 	"download-links-title": "Преземи книга",
-	"preview-book": "Преглед"
+	"preview-book": "Преглед",
+	"unknown-error": "Непозната грешка"
 }

static/skin/i18n/qqq.json

@@ -1,6 +1,7 @@
 {
 	"@metadata": {
 		"authors": [
+			"Amire80",
 			"Matthieu Gautier",
 			"Veloman Yunkan",
 			"Verdy p"
@@ -15,6 +16,7 @@
 	"suggest-search": "Suggest a search when the URL points to a non existing article",
 	"random-article-failure": "Failure of the random article selection procedure",
 	"invalid-raw-data-type": "Invalid DATATYPE was used with the /raw endpoint (/raw/<book>/DATATYPE/...); allowed values are 'meta' and 'content'",
+	"invalid-request": "Error text for malformed URLs.",
 	"no-value-for-arg": "Error text when no value has been provided for ARGUMENT in the request's query string",
 	"no-query": "Error text when no query has been provided for fulltext search",
 	"raw-entry-not-found": "Entry requested via the /raw endpoint was not found",
@@ -24,8 +26,14 @@
 	"404-page-heading": "Heading of the 404 error page",
 	"500-page-title": "Title of the 500 error page",
 	"500-page-heading": "Heading of the 500 error page",
+	"500-page-text": "Text of the 500 error page",
 	"fulltext-search-unavailable": "Title of the error page returned when search is attempted in a book without fulltext search database",
 	"no-search-results": "Text of the error page returned when search is attempted in a book without fulltext search database",
+	"search-results-page-title": "Title of the search results page",
+	"search-results-page-header": "Header of the search results page",
+	"empty-search-results-page-header": "Header of the empty search results page",
+	"search-result-book-info": "Reference to the book where the search result belongs (this is displayed AFTER the search result)",
+	"word-count": "Word count information",
 	"library-button-text": "Tooltip of the button leading to the welcome page",
 	"home-button-text": "Tooltip of the button leading to the main page of a book",
 	"random-page-button-text": "Tooltip of the button opening a randomly selected page",
@@ -52,5 +60,7 @@
 	"welcome-to-kiwix-server": "Title shown in browser's title bar/page tab",
 	"download-links-heading": "Heading for no-js download page",
 	"download-links-title": "Title for no-js download page",
-	"preview-book": "Tooltip of book-tile leading to the book"
+	"preview-book": "Tooltip of book-tile leading to the book",
+	"non-translated-text": "{{ignored}}\nUsed to display text that is generated at runtime and cannot be translated. Nothing to translate about this one.",
+	"unknown-error": "Unknown error"
 }

static/skin/i18n/sl.json

@@ -14,6 +14,7 @@
 	"suggest-search": "Preiščite celotno besedilo za <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>",
 	"random-article-failure": "Ups! Ni bilo mogoče izbrati naključnega članka :(",
 	"invalid-raw-data-type": "{{DATATYPE}} ni veljaven zahtevek za neobdelano vsebino.",
+	"invalid-request": "Zahtevani URL »{{{url}}}« ni veljaven zahtevek.",
 	"no-value-for-arg": "Argument {{ARGUMENT}} nima določene nobene vrednosti",
 	"no-query": "Poizvedba ni podana.",
 	"raw-entry-not-found": "Ni mogoče najti vnosa {{ENTRY}} tipa {{DATATYPE}}",
@@ -23,6 +24,7 @@
 	"404-page-heading": "Ni najdeno",
 	"500-page-title": "Notranja napaka strežnika",
 	"500-page-heading": "Notranja napaka strežnika",
+	"500-page-text": "Prišlo je do notranje napake strežnika. Žal nam je za to. :/",
 	"fulltext-search-unavailable": "Iskanje po celotnem besedilu ni na voljo",
 	"no-search-results": "Iskalnik po celotnem besedilu za to vsebino ni na voljo.",
 	"library-button-text": "Pojdite na pozdravno stran",
@@ -52,5 +54,6 @@
 	"welcome-to-kiwix-server": "Pozdravljeni na strežniku Kiwix",
 	"download-links-heading": "Povezave za prenos za <b><i>{{BOOK_TITLE}}</i></b>",
 	"download-links-title": "Prenesi knjigo",
-	"preview-book": "Predogled"
+	"preview-book": "Predogled",
+	"unknown-error": "Neznana napaka"
 }

static/skin/i18n/sv.json

@@ -15,6 +15,7 @@
 	"suggest-search": "Utför en fulltextsökning för <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>",
 	"random-article-failure": "Hoppsan! Kunde inte välja en slumpartikel :(",
 	"invalid-raw-data-type": "{{DATATYPE}} är ingen giltig begäran för oformaterat innehåll.",
+	"invalid-request": "Den begärda webbadressen \"{{{url}}}\" är inte en giltig begäran.",
 	"no-value-for-arg": "Inget värde angett för argumentet {{ARGUMENT}}",
 	"no-query": "Ingen fråga tillhandahålls.",
 	"raw-entry-not-found": "Kunde inte hitta {{DATATYPE}}-inlägget {{ENTRY}}",
@@ -24,6 +25,7 @@
 	"404-page-heading": "Hittades inte",
 	"500-page-title": "Internt serverfel",
 	"500-page-heading": "Internt serverfel",
+	"500-page-text": "Ett internt serverfel uppstod. Vi ber om ursäkt för det :/",
 	"fulltext-search-unavailable": "Fulltextsökning är inte tillgänglig",
 	"no-search-results": "Sökmaskinen för fulltext är inte tillgänglig för detta innehåll.",
 	"library-button-text": "Gå till hemsidan",
@@ -53,5 +55,6 @@
 	"welcome-to-kiwix-server": "Välkommen till Kiwix Server",
 	"download-links-heading": "Nedladdningslänkar för <b><i>{{BOOK_TITLE}}</i></b>",
 	"download-links-title": "Ladda ned bok",
-	"preview-book": "Förhandsgranska"
+	"preview-book": "Förhandsgranska",
+	"unknown-error": "Okänt fel"
 }

static/skin/i18n/test.json

@@ -40,4 +40,11 @@
 	, "download-links-heading": "[I18N] Download links for <b><i>{{BOOK_TITLE}}</i></b> [TESTING]"
 	, "download-links-title": "[I18N TESTING]Download book"
 	, "preview-book": "[I18N] Preview [TESTING]"
+	, "no-query" : "[I18N TESTING] Kiwix can read your thoughts but it is against GDPR. Please provide your query explicitly."
+	, "invalid-request" : "[I18N TESTING] Invalid URL: \"{{{url}}}\""
+	, "search-results-page-title": "[I18N TESTING] Search: {{SEARCH_PATTERN}}"
+	, "search-results-page-header": "[I18N TESTING] Results <b>{{START}}-{{END}}</b> of <b>{{COUNT}}</b> for <b>\"{{{SEARCH_PATTERN}}}\"</b>"
+	, "empty-search-results-page-header": "[I18N TESTING] No results were found for <b>\"{{{SEARCH_PATTERN}}}\"</b>"
+	, "search-result-book-info": "from [I18N TESTING] {{BOOK_TITLE}}"
+	, "word-count": "{{COUNT}} [I18N TESTING] words"
 }

static/skin/i18n/zh-hant.json

@@ -15,6 +15,7 @@
 	"suggest-search": "建立 <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a> 使用的全文搜尋",
 	"random-article-failure": "哎呀！隨機挑選條目失敗 :(",
 	"invalid-raw-data-type": "{{DATATYPE}}不是原始內容的有效請求。",
+	"invalid-request": "請求的 URL「{{{url}}}」不是有效的請求。",
 	"no-value-for-arg": "沒有為引數 {{ARGUMENT}} 提供內容",
 	"no-query": "未提供查詢。",
 	"raw-entry-not-found": "找不到{{DATATYPE}}項目{{ENTRY}}",
@@ -24,6 +25,7 @@
 	"404-page-heading": "查無頁面",
 	"500-page-title": "內部伺服器錯誤",
 	"500-page-heading": "內部伺服器錯誤",
+	"500-page-text": "內部伺服器發生錯誤。對此我們深感抱歉:/",
 	"fulltext-search-unavailable": "全文搜尋無效",
 	"no-search-results": "全文搜尋引擎不適用此內容。",
 	"library-button-text": "前往歡迎首頁",
@@ -53,5 +55,6 @@
 	"welcome-to-kiwix-server": "歡迎來到 Kiwix 伺服器",
 	"download-links-heading": "下載<b><i>{{BOOK_TITLE}}</i></b>的連結",
 	"download-links-title": "下載書籍",
-	"preview-book": "預覽"
+	"preview-book": "預覽",
+	"unknown-error": "不明錯誤"
 }

static/skin/languages.js

@@ -1,104 +1,172 @@
 const uiLanguages = [
   {
-    "الإنجليزية": "ar"
+    "iso_code": "ar",
+    "self_name": "الإنجليزية",
+    "translation_count": 25
   },
   {
-    "বাংলা": "bn"
+    "iso_code": "bn",
+    "self_name": "বাংলা",
+    "translation_count": 12
   },
   {
-    "Čeština": "cs"
+    "iso_code": "cs",
+    "self_name": "Čeština",
+    "translation_count": 25
   },
   {
-    "Deutsch": "de"
+    "iso_code": "de",
+    "self_name": "Deutsch",
+    "translation_count": 49
   },
   {
-    "English": "en"
+    "iso_code": "en",
+    "self_name": "English",
+    "translation_count": 58
   },
   {
-    "español": "es"
+    "iso_code": "es",
+    "self_name": "español",
+    "translation_count": 48
   },
   {
-    "suomi": "fi"
+    "iso_code": "fi",
+    "self_name": "suomi",
+    "translation_count": 22
   },
   {
-    "Français": "fr"
+    "iso_code": "fr",
+    "self_name": "Français",
+    "translation_count": 52
   },
   {
-    "עברית": "he"
+    "iso_code": "he",
+    "self_name": "עברית",
+    "translation_count": 52
   },
   {
-    "हिन्दी": "hi"
+    "iso_code": "hi",
+    "self_name": "हिन्दी",
+    "translation_count": 49
   },
   {
-    "Հայերեն": "hy"
+    "iso_code": "hy",
+    "self_name": "Հայերեն",
+    "translation_count": 15
   },
   {
-    "interlingua": "ia"
+    "iso_code": "ia",
+    "self_name": "interlingua",
+    "translation_count": 49
   },
   {
-    "italiano": "it"
+    "iso_code": "it",
+    "self_name": "italiano",
+    "translation_count": 29
   },
   {
-    "日本語": "ja"
+    "iso_code": "ja",
+    "self_name": "日本語",
+    "translation_count": 26
   },
   {
-    "한국어": "ko"
+    "iso_code": "ko",
+    "self_name": "한국어",
+    "translation_count": 13
   },
   {
-    "kurdî": "ku-latn"
+    "iso_code": "ku-latn",
+    "self_name": "kurdî",
+    "translation_count": 26
   },
   {
-    "Lëtzebuergesch": "lb"
+    "iso_code": "lb",
+    "self_name": "Lëtzebuergesch",
+    "translation_count": 22
   },
   {
-    "македонски": "mk"
+    "iso_code": "mk",
+    "self_name": "македонски",
+    "translation_count": 52
   },
   {
-    "Bahasa Melayu": "ms"
+    "iso_code": "ms",
+    "self_name": "Bahasa Melayu",
+    "translation_count": 14
   },
   {
-    "Nederlands": "nl"
+    "iso_code": "nl",
+    "self_name": "Nederlands",
+    "translation_count": 49
   },
   {
-    "ߒߞߏ": "nqo"
+    "iso_code": "nqo",
+    "self_name": "ߒߞߏ",
+    "translation_count": 43
   },
   {
-    "ଓଡ଼ିଆ": "or"
+    "iso_code": "or",
+    "self_name": "ଓଡ଼ିଆ",
+    "translation_count": 49
   },
   {
-    "Polski": "pl"
+    "iso_code": "pl",
+    "self_name": "Polski",
+    "translation_count": 24
   },
   {
-    "русский": "ru"
+    "iso_code": "ru",
+    "self_name": "русский",
+    "translation_count": 45
   },
   {
-    "Sardu": "sc"
+    "iso_code": "sc",
+    "self_name": "Sardu",
+    "translation_count": 49
   },
   {
-    "slovenčina": "sk"
+    "iso_code": "sk",
+    "self_name": "slovenčina",
+    "translation_count": 25
   },
   {
-    "سرائیکی": "skr-arab"
+    "iso_code": "skr-arab",
+    "self_name": "سرائیکی",
+    "translation_count": 20
   },
   {
-    "slovenščina": "sl"
+    "iso_code": "sl",
+    "self_name": "slovenščina",
+    "translation_count": 52
   },
   {
-    "Shqip": "sq"
+    "iso_code": "sq",
+    "self_name": "Shqip",
+    "translation_count": 49
   },
   {
-    "Svenska": "sv"
+    "iso_code": "sv",
+    "self_name": "Svenska",
+    "translation_count": 52
   },
   {
-    "ఇంగ్లీషు": "te"
+    "iso_code": "te",
+    "self_name": "ఇంగ్లీషు",
+    "translation_count": 49
   },
   {
-    "Türkçe": "tr"
+    "iso_code": "tr",
+    "self_name": "Türkçe",
+    "translation_count": 25
   },
   {
-    "英语": "zh-hans"
+    "iso_code": "zh-hans",
+    "self_name": "英语",
+    "translation_count": 16
   },
   {
-    "繁體中文": "zh-hant"
+    "iso_code": "zh-hant",
+    "self_name": "繁體中文",
+    "translation_count": 52
   }
 ]

static/skin/viewer.js

@@ -10,13 +10,22 @@ let viewerState = {
   uiLanguage: 'en',
 };
 
+function dropUserLang(query) {
+  const q = new URLSearchParams(query);
+  q.delete('userlang');
+  const pre = (query.startsWith('?') && q.size != 0 ? '?' : '');
+  return pre + q.toString();
+}
+
 function userUrl2IframeUrl(url) {
   if ( url == '' ) {
     return blankPageUrl;
   }
 
   if ( url.startsWith('search?') ) {
-    return `${root}/${url}`;
+    const q = new URLSearchParams(url.slice("search?".length));
+    q.set('userlang', viewerState.uiLanguage);
+    return `${root}/search?${q.toString()}`;
   }
 
   return `${root}/content/${url}`;
@@ -73,7 +82,7 @@ function quasiUriEncode(s, specialSymbols) {
 function performSearch() {
   const searchbox = document.getElementById('kiwixsearchbox');
   const q = encodeURIComponent(searchbox.value);
-  gotoUrl(`/search?books.name=${currentBook}&pattern=${q}`);
+  gotoUrl(`/search?books.name=${currentBook}&pattern=${q}&userlang=${viewerState.uiLanguage}`);
 }
 
 function makeJSLink(jsCodeString, linkText, linkAttr="") {
@@ -148,7 +157,7 @@ function iframeUrl2UserUrl(url, query) {
   }
 
   if ( url == `${root}/search` ) {
-    return `search${query}`;
+    return `search${dropUserLang(query)}`;
   }
 
   url = url.slice(root.length);
@@ -249,6 +258,25 @@ function handle_location_hash_change() {
   history.replaceState(viewerState, null);
 }
 
+function translateErrorPageIfNeeded() {
+  const cw = contentIframe.contentWindow;
+  if ( cw.KIWIX_RESPONSE_TEMPLATE && cw.KIWIX_RESPONSE_DATA ) {
+    const template = htmlDecode(cw.KIWIX_RESPONSE_TEMPLATE);
+
+    // cw.KIWIX_RESPONSE_DATA belongs to the iframe context and running
+    // I18n.render() on it directly in the top context doesn't work correctly
+    // because the type checks (obj.__proto__ == ???.prototype) in
+    // I18n.instantiateParameterizedMessages() always fail (String.prototype
+    // refers to different objects in different contexts).
+    // Work arround that issue by copying the object into our context.
+    const params = JSON.parse(JSON.stringify(cw.KIWIX_RESPONSE_DATA));
+
+    const html = I18n.render(template, params);
+    const htmlDoc = new DOMParser().parseFromString(html, "text/html");
+    cw.document.documentElement.innerHTML = htmlDoc.documentElement.innerHTML;
+  }
+}
+
 function handle_content_url_change() {
   const iframeLocation = contentIframe.contentWindow.location;
   console.log('handle_content_url_change: ' + iframeLocation.href);
@@ -258,6 +286,7 @@ function handle_content_url_change() {
   const newHash = iframeUrl2UserUrl(iframeContentUrl, iframeContentQuery);
   history.replaceState(viewerState, null, makeURL(location.search, newHash));
   updateCurrentBookIfNeeded(newHash);
+  translateErrorPageIfNeeded();
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -290,12 +319,23 @@ function isExternalUrl(url) {
       || url.startsWith("https:");
 }
 
+function getRealHref(target) {
+  // In case of wombat in the middle, wombat will rewrite the href value to the original url (external link)
+  // This is not what we want. Let's ask wombat to not rewrite href
+  const old_no_rewrite = target._no_rewrite;
+  target._no_rewrite = true;
+  const target_href = target.href;
+  target._no_rewrite = old_no_rewrite;
+  return target_href;
+}
+
 function onClickEvent(e) {
   const iframeDocument = contentIframe.contentDocument;
   const target = matchingAncestorElement(e.target, iframeDocument, "a");
   if (target !== null && "href" in target) {
-    if ( isExternalUrl(target.href) ) {
-      const possiblyBlockedLink = blockLink(target.href);
+    const target_href = getRealHref(target);
+    if (isExternalUrl(target_href)) {
+      const possiblyBlockedLink = blockLink(target_href);
       if ( e.ctrlKey || e.shiftKey ) {
         // The link will be loaded in a new tab/window - update the link
         // and let the browser handle the rest.
@@ -485,6 +525,7 @@ function changeUILanguage() {
   viewerState.uiLanguage = lang;
   setUserLanguage(lang, () => {
     updateUIText();
+    translateErrorPageIfNeeded();
     history.pushState(viewerState, null);
   });
 }
@@ -505,9 +546,8 @@ function setupViewer() {
   const lang = getUserLanguage();
   setUserLanguage(lang, finishViewerSetupOnceTranslationsAreLoaded);
   viewerState.uiLanguage = lang;
-  const q = new URLSearchParams(window.location.search);
-  q.delete('userlang');
-  const rewrittenURL = makeURL(q.toString(), location.hash);
+  const cleanedUpQuery = dropUserLang(window.location.search);
+  const rewrittenURL = makeURL(cleanedUpQuery, location.hash);
   history.replaceState(viewerState, null, rewrittenURL);
 
   kiwixToolBarWrapper.style.display = 'block';

static/templates/error.html

@@ -5,7 +5,10 @@
     <title>{{PAGE_TITLE}}</title>
 {{#CSS_URL}}
     <link type="text/css" href="{{{CSS_URL}}}" rel="Stylesheet" />
-{{/CSS_URL}}
+{{/CSS_URL}}{{#KIWIX_RESPONSE_DATA}}    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = "{{KIWIX_RESPONSE_TEMPLATE}}";
+      window.KIWIX_RESPONSE_DATA = {{{KIWIX_RESPONSE_DATA}}};
+    </script>{{/KIWIX_RESPONSE_DATA}}
   </head>
   <body>
     <h1>{{PAGE_HEADING}}</h1>

static/templates/search_result.html

@@ -102,23 +102,11 @@
       }
 
     </style>
-    <title>Search: {{query.pattern}}</title>
+    <title>{{PAGE_TITLE}}</title>
   </head>
   <body bgcolor="white">
     <div class="header">
-      {{#results.hasResults}}
-        Results
-        <b>
-          {{results.start}}-{{results.end}}
-        </b> of <b>
-          {{results.count}}
-        </b> for <b>
-          "{{{query.pattern}}}"
-        </b>
-      {{/results.hasResults}}
-      {{^results.hasResults}}
-        No results were found for <b>"{{{query.pattern}}}"</b>
-      {{/results.hasResults}}
+      {{{PAGE_HEADER}}}
     </div>
 
     <div class="results">
@@ -131,12 +119,12 @@
             {{#snippet}}
               <cite>{{>snippet}}...</cite>
             {{/snippet}}
-            {{#bookTitle}}
-              <div class="book-title">from {{bookTitle}}</div>
-            {{/bookTitle}}
-            {{#wordCount}}
-              <div class="informations">{{wordCount}} words</div>
-            {{/wordCount}}
+            {{#bookInfo}}
+              <div class="book-title">{{bookInfo}}</div>
+            {{/bookInfo}}
+            {{#wordCountInfo}}
+              <div class="informations">{{wordCountInfo}}</div>
+            {{/wordCountInfo}}
           </li>
         {{/results.items}}
       </ul>

static/templates/viewer_settings.js

@@ -1,6 +1,5 @@
 const viewerSettings = {
   toolbarEnabled:       {{enable_toolbar}},
   linkBlockingEnabled:  {{enable_link_blocking}},
-  libraryButtonEnabled: {{enable_library_button}},
-  defaultUserLanguage:  "{{default_user_language}}"
+  libraryButtonEnabled: {{enable_library_button}}
 }

test/httplib.h

@@ -1516,7 +1516,7 @@ inline bool bind_ip_address(socket_t sock, const char *host) {
 }
 
 inline std::string if2ip(const std::string &ifn) {
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__HAIKU__)
   struct ifaddrs *ifap;
   getifaddrs(&ifap);
   for (auto ifa = ifap; ifa; ifa = ifa->ifa_next) {

test/i18n.cpp

@@ -0,0 +1,50 @@
+#include "../src/server/i18n.h"
+#include "gtest/gtest.h"
+
+using namespace kiwix;
+
+TEST(ParameterizedMessage, parameterlessMessages)
+{
+  {
+    const ParameterizedMessage msg("404-page-title", {});
+
+    EXPECT_EQ(msg.getText("en"),   "Content not found");
+    EXPECT_EQ(msg.getText("test"), "[I18N TESTING] Not Found - Try Again");
+  }
+
+  {
+    // Make sure that msgId influences the result of getText()
+    const ParameterizedMessage msg("random-page-button-text", {});
+
+    EXPECT_EQ(msg.getText("en"),   "Go to a randomly selected page");
+    EXPECT_EQ(msg.getText("test"), "[I18N TESTING] I am tired of determinism");
+  }
+
+  {
+    // Demonstrate that unwanted parameters are silently ignored
+    const ParameterizedMessage msg("404-page-title", {{"abc", "xyz"}});
+
+    EXPECT_EQ(msg.getText("en"),   "Content not found");
+    EXPECT_EQ(msg.getText("test"), "[I18N TESTING] Not Found - Try Again");
+  }
+}
+
+TEST(ParameterizedMessage, messagesWithParameters)
+{
+  {
+    const ParameterizedMessage msg("filter-by-tag",
+                                   {{"TAG", "scifi"}}
+    );
+
+    EXPECT_EQ(msg.getText("en"),   "Filter by tag \"scifi\"");
+    EXPECT_EQ(msg.getText("test"), "Filter [I18N] by [TESTING] tag \"scifi\"");
+  }
+
+  {
+    // Omitting expected parameters amounts to using empty values for them
+    const ParameterizedMessage msg("filter-by-tag", {});
+
+    EXPECT_EQ(msg.getText("en"),   "Filter by tag \"\"");
+    EXPECT_EQ(msg.getText("test"), "Filter [I18N] by [TESTING] tag \"\"");
+  }
+}

test/meson.build

@@ -13,7 +13,9 @@ tests = [
     'name_mapper',
     'opds_catalog',
     'server_helper',
-    'lrucache'
+    'lrucache',
+    'i18n',
+    'response'
 ]
 
 if build_machine.system() != 'windows'

test/otherTools.cpp

@@ -110,10 +110,10 @@ TEST(Suggestions, specialCharHandling)
     CHECK_SUGGESTIONS(s.getJSON(),
 R"EXPECTEDJSON([
   {
-    "value" : "Title with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
-    "label" : "Snippet with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
+    "value" : "Title with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
+    "label" : "Snippet with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
     "kind" : "path"
-      , "path" : "Path with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?"
+      , "path" : "Path with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?"
   }
 ]
 )EXPECTEDJSON"
@@ -128,10 +128,10 @@ R"EXPECTEDJSON([
     CHECK_SUGGESTIONS(s.getJSON(),
 R"EXPECTEDJSON([
   {
-    "value" : "Snippetless title with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
-    "label" : "Snippetless title with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
+    "value" : "Snippetless title with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
+    "label" : "Snippetless title with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?",
     "kind" : "path"
-      , "path" : "Path with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?"
+      , "path" : "Path with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?"
   }
 ]
 )EXPECTEDJSON"
@@ -145,8 +145,8 @@ R"EXPECTEDJSON([
     CHECK_SUGGESTIONS(s.getJSON(),
 R"EXPECTEDJSON([
   {
-    "value" : "text with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.? ",
-    "label" : "containing 'text with \u0009\u0010\u0013\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?'...",
+    "value" : "text with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.? ",
+    "label" : "containing 'text with \t\n\r\\<>&'"~!@#$%^*()_+`-=[]{}|:;,.?'...",
     "kind" : "pattern"
     //EOLWHITESPACEMARKER
   }

test/response.cpp

@@ -0,0 +1,101 @@
+#include "../src/server/response.h"
+#include "gtest/gtest.h"
+
+#include "../src/server/request_context.h"
+
+namespace
+{
+
+using namespace kiwix;
+
+RequestContext makeHttpGetRequest(const std::string& url,
+                                  const RequestContext::NameValuePairs& headers,
+                                  const RequestContext::NameValuePairs& queryArgs)
+{
+  return RequestContext("", url, "GET", "1.1", headers, queryArgs);
+}
+
+std::string getResponseContent(const ContentResponseBlueprint& crb)
+{
+  return crb.generateResponseObject()->getContent();
+}
+
+} // unnamed namespace
+
+
+
+TEST(HTTPErrorResponse, shouldBeInEnglishByDefault) {
+  const RequestContext req = makeHttpGetRequest("/asdf", {}, {});
+  HTTPErrorResponse errResp(req, MHD_HTTP_NOT_FOUND,
+                            "404-page-title",
+                            "404-page-heading",
+                            "/css/error.css",
+                            /*includeKiwixResponseData=*/true);
+
+  errResp += ParameterizedMessage("suggest-search",
+                              {
+                                { "PATTERN",    "asdf"   },
+                                { "SEARCH_URL", "/search?q=asdf" }
+             });
+
+  EXPECT_EQ(getResponseContent(errResp),
+R"(<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <meta content="text/html;charset=UTF-8" http-equiv="content-type" />
+    <title>Content not found</title>
+    <link type="text/css" href="/css/error.css" rel="Stylesheet" />
+    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = "&lt;!DOCTYPE html&gt;\n&lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;&gt;\n  &lt;head&gt;\n    &lt;meta content=&quot;text/html;charset=UTF-8&quot; http-equiv=&quot;content-type&quot; /&gt;\n    &lt;title&gt;{{PAGE_TITLE}}&lt;/title&gt;\n{{#CSS_URL}}\n    &lt;link type=&quot;text/css&quot; href=&quot;{{{CSS_URL}}}&quot; rel=&quot;Stylesheet&quot; /&gt;\n{{/CSS_URL}}{{#KIWIX_RESPONSE_DATA}}    &lt;script&gt;\n      window.KIWIX_RESPONSE_TEMPLATE = &quot;{{KIWIX_RESPONSE_TEMPLATE}}&quot;;\n      window.KIWIX_RESPONSE_DATA = {{{KIWIX_RESPONSE_DATA}}};\n    &lt;/script&gt;{{/KIWIX_RESPONSE_DATA}}\n  &lt;/head&gt;\n  &lt;body&gt;\n    &lt;h1&gt;{{PAGE_HEADING}}&lt;/h1&gt;\n{{#details}}\n    &lt;p&gt;\n      {{{p}}}\n    &lt;/p&gt;\n{{/details}}\n  &lt;/body&gt;\n&lt;/html&gt;\n";
+      window.KIWIX_RESPONSE_DATA = { "CSS_URL" : "/css/error.css", "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "asdf", "SEARCH_URL" : "/search?q=asdf" } } } ] };
+    </script>
+  </head>
+  <body>
+    <h1>Not Found</h1>
+    <p>
+      Make a full text search for <a href="/search?q=asdf">asdf</a>
+    </p>
+  </body>
+</html>
+)");
+}
+
+TEST(HTTPErrorResponse, shouldBeTranslatable) {
+  const RequestContext req = makeHttpGetRequest("/asdf",
+                              /* headers */     {},
+                              /* query args */  {{"userlang", "test"}}
+  );
+
+  HTTPErrorResponse errResp(req, MHD_HTTP_NOT_FOUND,
+                            "404-page-title",
+                            "404-page-heading",
+                            "/css/error.css",
+                            /*includeKiwixResponseData=*/true);
+
+  errResp += ParameterizedMessage("suggest-search",
+                              {
+                                { "PATTERN",    "asdf"   },
+                                { "SEARCH_URL", "/search?q=asdf" }
+             });
+
+  EXPECT_EQ(getResponseContent(errResp),
+R"(<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <meta content="text/html;charset=UTF-8" http-equiv="content-type" />
+    <title>[I18N TESTING] Not Found - Try Again</title>
+    <link type="text/css" href="/css/error.css" rel="Stylesheet" />
+    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = "&lt;!DOCTYPE html&gt;\n&lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;&gt;\n  &lt;head&gt;\n    &lt;meta content=&quot;text/html;charset=UTF-8&quot; http-equiv=&quot;content-type&quot; /&gt;\n    &lt;title&gt;{{PAGE_TITLE}}&lt;/title&gt;\n{{#CSS_URL}}\n    &lt;link type=&quot;text/css&quot; href=&quot;{{{CSS_URL}}}&quot; rel=&quot;Stylesheet&quot; /&gt;\n{{/CSS_URL}}{{#KIWIX_RESPONSE_DATA}}    &lt;script&gt;\n      window.KIWIX_RESPONSE_TEMPLATE = &quot;{{KIWIX_RESPONSE_TEMPLATE}}&quot;;\n      window.KIWIX_RESPONSE_DATA = {{{KIWIX_RESPONSE_DATA}}};\n    &lt;/script&gt;{{/KIWIX_RESPONSE_DATA}}\n  &lt;/head&gt;\n  &lt;body&gt;\n    &lt;h1&gt;{{PAGE_HEADING}}&lt;/h1&gt;\n{{#details}}\n    &lt;p&gt;\n      {{{p}}}\n    &lt;/p&gt;\n{{/details}}\n  &lt;/body&gt;\n&lt;/html&gt;\n";
+      window.KIWIX_RESPONSE_DATA = { "CSS_URL" : "/css/error.css", "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "asdf", "SEARCH_URL" : "/search?q=asdf" } } } ] };
+    </script>
+  </head>
+  <body>
+    <h1>[I18N TESTING] Content not found, but at least the server is alive</h1>
+    <p>
+      [I18N TESTING] Make a full text search for <a href="/search?q=asdf">asdf</a>
+    </p>
+  </body>
+</html>
+)");
+}

test/server.cpp

@@ -59,7 +59,7 @@ const ResourceCollection resources200Compressible{
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/autoComplete/css/autoComplete.css" },
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/autoComplete/css/autoComplete.css?cacheid=ef30cd42" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/i18n.js" },
-  { STATIC_CONTENT,  "/ROOT%23%3F/skin/i18n.js?cacheid=6a8c6fb2" },
+  { STATIC_CONTENT,  "/ROOT%23%3F/skin/i18n.js?cacheid=071abc9a" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/index.css" },
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/index.css?cacheid=1e78e7cf" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/index.js" },
@@ -75,7 +75,7 @@ const ResourceCollection resources200Compressible{
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/taskbar.css" },
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/taskbar.css?cacheid=e014a885" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/viewer.js" },
-  { STATIC_CONTENT,  "/ROOT%23%3F/skin/viewer.js?cacheid=201653b8" },
+  { STATIC_CONTENT,  "/ROOT%23%3F/skin/viewer.js?cacheid=5fc4badf" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/fonts/Poppins.ttf" },
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/fonts/Poppins.ttf?cacheid=af705837" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/fonts/Roboto.ttf" },
@@ -83,6 +83,8 @@ const ResourceCollection resources200Compressible{
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/i18n/test.json" },
   // TODO: implement cache management of i18n resources
   //{ STATIC_CONTENT, "/ROOT%23%3F/skin/i18n/test.json?cacheid=unknown" },
+  { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/languages.js" },
+  { STATIC_CONTENT, "/ROOT%23%3F/skin/languages.js?cacheid=9ccd43fd" },
 
   { DYNAMIC_CONTENT, "/ROOT%23%3F/catalog/search" },
 
@@ -148,8 +150,6 @@ const ResourceCollection resources200Uncompressible{
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/search-icon.svg?cacheid=b10ae7ed" },
   { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/search_results.css" },
   { STATIC_CONTENT,  "/ROOT%23%3F/skin/search_results.css?cacheid=76d39c84" },
-  { DYNAMIC_CONTENT, "/ROOT%23%3F/skin/languages.js" },
-  { STATIC_CONTENT, "/ROOT%23%3F/skin/languages.js?cacheid=96f2cf73" },
 
   { ZIM_CONTENT,     "/ROOT%23%3F/raw/zimfile/meta/Title" },
   { ZIM_CONTENT,     "/ROOT%23%3F/raw/zimfile/meta/Description" },
@@ -285,8 +285,8 @@ R"EXPECTEDRESULT(      href="/ROOT%23%3F/skin/kiwix.css?cacheid=2158fad9"
     <link rel="mask-icon" href="/ROOT%23%3F/skin/favicon/safari-pinned-tab.svg?cacheid=8d487e95" color="#5bbad5">
     <link rel="shortcut icon" href="/ROOT%23%3F/skin/favicon/favicon.ico?cacheid=92663314">
     <meta name="msapplication-config" content="/ROOT%23%3F/skin/favicon/browserconfig.xml?cacheid=f29a7c4a">
-    <script type="module" src="/ROOT%23%3F/skin/i18n.js?cacheid=6a8c6fb2" defer></script>
-    <script type="text/javascript" src="/ROOT%23%3F/skin/languages.js?cacheid=96f2cf73" defer></script>
+    <script type="module" src="/ROOT%23%3F/skin/i18n.js?cacheid=071abc9a" defer></script>
+    <script type="text/javascript" src="/ROOT%23%3F/skin/languages.js?cacheid=9ccd43fd" defer></script>
     <script src="/ROOT%23%3F/skin/isotope.pkgd.min.js?cacheid=2e48d392" defer></script>
     <script src="/ROOT%23%3F/skin/iso6391To3.js?cacheid=ecde2bb3"></script>
     <script type="text/javascript" src="/ROOT%23%3F/skin/index.js?cacheid=ce19da2a" defer></script>
@@ -318,9 +318,9 @@ R"EXPECTEDRESULT(                                <img src="${root}/skin/download
 R"EXPECTEDRESULT(    <link type="text/css" href="./skin/kiwix.css?cacheid=2158fad9" rel="Stylesheet" />
     <link type="text/css" href="./skin/taskbar.css?cacheid=e014a885" rel="Stylesheet" />
     <link type="text/css" href="./skin/autoComplete/css/autoComplete.css?cacheid=ef30cd42" rel="Stylesheet" />
-    <script type="module" src="./skin/i18n.js?cacheid=6a8c6fb2" defer></script>
-    <script type="text/javascript" src="./skin/languages.js?cacheid=96f2cf73" defer></script>
-    <script type="text/javascript" src="./skin/viewer.js?cacheid=201653b8" defer></script>
+    <script type="module" src="./skin/i18n.js?cacheid=071abc9a" defer></script>
+    <script type="text/javascript" src="./skin/languages.js?cacheid=9ccd43fd" defer></script>
+    <script type="text/javascript" src="./skin/viewer.js?cacheid=5fc4badf" defer></script>
     <script type="text/javascript" src="./skin/autoComplete/autoComplete.min.js?cacheid=1191aaaf"></script>
       const blankPageUrl = root + "/skin/blank.html?cacheid=6b1fa032";
           <label for="kiwix_button_show_toggle"><img src="./skin/caret.png?cacheid=22b942b4" alt=""></label>
@@ -337,6 +337,7 @@ R"EXPECTEDRESULT(    <link type="text/css" href="./skin/kiwix.css?cacheid=2158fa
       // a page rendered from static/templates/no_search_result_html
       /* url */ "/ROOT%23%3F/search?content=poor&pattern=whatever",
 R"EXPECTEDRESULT(    <link type="text/css" href="/ROOT%23%3F/skin/search_results.css?cacheid=76d39c84" rel="Stylesheet" />
+      window.KIWIX_RESPONSE_DATA = { "CSS_URL" : "/ROOT%23%3F/skin/search_results.css?cacheid=76d39c84", "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "fulltext-search-unavailable", "params" : { } }, "details" : [ { "p" : { "msgid" : "no-search-results", "params" : { } } } ] };
 )EXPECTEDRESULT"
     },
   };
@@ -535,6 +536,7 @@ struct ExpectedResponseData
 {
   const std::string expectedPageTitle;
   const std::string expectedCssUrl;
+  const std::string expectedKiwixResponseData;
   const std::string bookName;
   const std::string bookTitle;
   const std::string expectedBody;
@@ -544,6 +546,7 @@ enum ExpectedResponseDataType
 {
   expected_page_title,
   expected_css_url,
+  expected_kiwix_response_data,
   book_name,
   book_title,
   expected_body
@@ -556,11 +559,13 @@ ExpectedResponseData operator==(ExpectedResponseDataType t, std::string s)
 {
   switch (t)
   {
-    case expected_page_title: return ExpectedResponseData{s, "", "", "", ""};
-    case expected_css_url:    return ExpectedResponseData{"", s, "", "", ""};
-    case book_name:           return ExpectedResponseData{"", "", s, "", ""};
-    case book_title:          return ExpectedResponseData{"", "", "", s, ""};
-    case expected_body:       return ExpectedResponseData{"", "", "", "", s};
+    case expected_page_title: return ExpectedResponseData{s, "", "", "", "", ""};
+    case expected_css_url:    return ExpectedResponseData{"", s, "", "", "", ""};
+    case expected_kiwix_response_data:
+                              return ExpectedResponseData{"", "", s, "", "", ""};
+    case book_name:           return ExpectedResponseData{"", "", "", s, "", ""};
+    case book_title:          return ExpectedResponseData{"", "", "", "", s, ""};
+    case expected_body:       return ExpectedResponseData{"", "", "", "", "", s};
     default: assert(false); return ExpectedResponseData{};
   }
 }
@@ -579,6 +584,7 @@ ExpectedResponseData operator&&(const ExpectedResponseData& a,
   return ExpectedResponseData{
     selectNonEmpty(a.expectedPageTitle, b.expectedPageTitle),
     selectNonEmpty(a.expectedCssUrl, b.expectedCssUrl),
+    selectNonEmpty(a.expectedKiwixResponseData, b.expectedKiwixResponseData),
     selectNonEmpty(a.bookName, b.bookName),
     selectNonEmpty(a.bookTitle, b.bookTitle),
     selectNonEmpty(a.expectedBody, b.expectedBody)
@@ -607,19 +613,29 @@ private:
 std::string TestContentIn404HtmlResponse::expectedResponse() const
 {
   const std::string frag[] =  {
+    // frag[0]
     R"FRAG(<!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
     <meta content="text/html;charset=UTF-8" http-equiv="content-type" />
     <title>)FRAG",
 
+    // frag[1]
     R"FRAG(</title>
 )FRAG",
 
-    R"FRAG(
+    // frag[2]
+    R"(    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = )" + ERROR_HTML_TEMPLATE_JS_STRING + R"(;
+      window.KIWIX_RESPONSE_DATA = )",
+
+    // frag[3]
+    R"FRAG(;
+    </script>
   </head>
   <body>)FRAG",
 
+  // frag[4]
   R"FRAG(  </body>
 </html>
 )FRAG"
@@ -630,8 +646,10 @@ std::string TestContentIn404HtmlResponse::expectedResponse() const
        + frag[1]
        + pageCssLink()
        + frag[2]
+       + expectedKiwixResponseData
+       + frag[3]
        + expectedBody
-       + frag[3];
+       + frag[4];
 }
 
 std::string TestContentIn404HtmlResponse::pageTitle() const
@@ -648,7 +666,8 @@ std::string TestContentIn404HtmlResponse::pageCssLink() const
 
   return R"(    <link type="text/css" href=")"
        + expectedCssUrl
-       + R"(" rel="Stylesheet" />)";
+       + R"(" rel="Stylesheet" />)"
+       + "\n";
 }
 
 class TestContentIn400HtmlResponse : public TestContentIn404HtmlResponse
@@ -676,6 +695,7 @@ TEST_F(ServerTest, Http404HtmlError)
   using namespace TestingOfHtmlResponses;
   const std::vector<TestContentIn404HtmlResponse> testData{
     { /* url */ "/ROOT%23%3F/random?content=non-existent-book",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "non-existent-book" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -685,6 +705,7 @@ TEST_F(ServerTest, Http404HtmlError)
 
     { /* url */ "/ROOT%23%3F/random?content=non-existent-book&userlang=test",
       expected_page_title=="[I18N TESTING] Not Found - Try Again" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "non-existent-book" } } } ] })" &&
       expected_body==R"(
     <h1>[I18N TESTING] Content not found, but at least the server is alive</h1>
     <p>
@@ -693,6 +714,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/suggest?content=no-such-book&term=whatever",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "no-such-book" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -701,6 +723,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/catalog/",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/catalog/" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -710,6 +733,7 @@ TEST_F(ServerTest, Http404HtmlError)
 
     { /* url */ "/ROOT%23%3F/catalog/?userlang=test",
       expected_page_title=="[I18N TESTING] Not Found - Try Again" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/catalog/" } } } ] })" &&
       expected_body==R"(
     <h1>[I18N TESTING] Content not found, but at least the server is alive</h1>
     <p>
@@ -718,6 +742,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/catalog/invalid_endpoint",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/catalog/invalid_endpoint" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -727,6 +752,7 @@ TEST_F(ServerTest, Http404HtmlError)
 
     { /* url */ "/ROOT%23%3F/catalog/invalid_endpoint?userlang=test",
       expected_page_title=="[I18N TESTING] Not Found - Try Again" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/catalog/invalid_endpoint" } } } ] })" &&
       expected_body==R"(
     <h1>[I18N TESTING] Content not found, but at least the server is alive</h1>
     <p>
@@ -735,6 +761,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/content/invalid-book/whatever",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/invalid-book/whatever" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "whatever", "SEARCH_URL" : "/ROOT%23%3F/search?pattern=whatever" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -748,6 +775,7 @@ TEST_F(ServerTest, Http404HtmlError)
     { /* url */ "/ROOT%23%3F/content/zimfile/invalid-article",
       book_name=="zimfile" &&
       book_title=="Ray Charles" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/zimfile/invalid-article" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "invalid-article", "SEARCH_URL" : "/ROOT%23%3F/search?content=zimfile&pattern=invalid-article" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -759,6 +787,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ R"(/ROOT%23%3F/content/"><svg onload=alert(1)>)",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/\"><svg onload%3Dalert(1)>" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "\"><svg onload=alert(1)>", "SEARCH_URL" : "/ROOT%23%3F/search?pattern=%22%3E%3Csvg%20onload%3Dalert(1)%3E" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -772,6 +801,7 @@ TEST_F(ServerTest, Http404HtmlError)
     { /* url */ R"(/ROOT%23%3F/content/zimfile/"><svg onload=alert(1)>)",
       book_name=="zimfile" &&
       book_title=="Ray Charles" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/zimfile/\"><svg onload%3Dalert(1)>" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "\"><svg onload=alert(1)>", "SEARCH_URL" : "/ROOT%23%3F/search?content=zimfile&pattern=%22%3E%3Csvg%20onload%3Dalert(1)%3E" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -782,10 +812,27 @@ TEST_F(ServerTest, Http404HtmlError)
     </p>
 )"  },
 
+    // XXX: This test case is against a "</script>" string appearing inside
+    // XXX: javascript code that will confuse the HTML parser
+    { /* url */ R"(/ROOT%23%3F/content/zimfile/</script>)",
+      book_name=="zimfile" &&
+      book_title=="Ray Charles" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/zimfile/</scr\ipt>" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "script>", "SEARCH_URL" : "/ROOT%23%3F/search?content=zimfile&pattern=script%3E" } } } ] })" &&
+      expected_body==R"(
+    <h1>Not Found</h1>
+    <p>
+      The requested URL "/ROOT%23%3F/content/zimfile/&lt;/script&gt;" was not found on this server.
+    </p>
+    <p>
+      Make a full text search for <a href="/ROOT%23%3F/search?content=zimfile&pattern=script%3E">script&gt;</a>
+    </p>
+)"  },
+
     { /* url */ "/ROOT%23%3F/content/zimfile/invalid-article?userlang=test",
       expected_page_title=="[I18N TESTING] Not Found - Try Again" &&
       book_name=="zimfile" &&
       book_title=="Ray Charles" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/content/zimfile/invalid-article" } } }, { "p" : { "msgid" : "suggest-search", "params" : { "PATTERN" : "invalid-article", "SEARCH_URL" : "/ROOT%23%3F/search?content=zimfile&pattern=invalid-article" } } } ] })" &&
       expected_body==R"(
     <h1>[I18N TESTING] Content not found, but at least the server is alive</h1>
     <p>
@@ -797,6 +844,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/raw/no-such-book/meta/Title",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/raw/no-such-book/meta/Title" } } }, { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "no-such-book" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -808,6 +856,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/raw/zimfile/XYZ",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/raw/zimfile/XYZ" } } }, { "p" : { "msgid" : "invalid-raw-data-type", "params" : { "DATATYPE" : "XYZ" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -819,6 +868,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/raw/zimfile/meta/invalid-metadata",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/raw/zimfile/meta/invalid-metadata" } } }, { "p" : { "msgid" : "raw-entry-not-found", "params" : { "DATATYPE" : "meta", "ENTRY" : "invalid-metadata" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -830,6 +880,7 @@ TEST_F(ServerTest, Http404HtmlError)
 )"  },
 
     { /* url */ "/ROOT%23%3F/raw/zimfile/content/invalid-article",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "404-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "url-not-found", "params" : { "url" : "/ROOT%23%3F/raw/zimfile/content/invalid-article" } } }, { "p" : { "msgid" : "raw-entry-not-found", "params" : { "DATATYPE" : "content", "ENTRY" : "invalid-article" } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -845,6 +896,7 @@ TEST_F(ServerTest, Http404HtmlError)
       expected_css_url=="/ROOT%23%3F/skin/search_results.css?cacheid=76d39c84" &&
       book_name=="poor" &&
       book_title=="poor" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : "/ROOT%23%3F/skin/search_results.css?cacheid=76d39c84", "PAGE_HEADING" : { "msgid" : "404-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "fulltext-search-unavailable", "params" : { } }, "details" : [ { "p" : { "msgid" : "no-search-results", "params" : { } } } ] })" &&
       expected_body==R"(
     <h1>Not Found</h1>
     <p>
@@ -866,6 +918,7 @@ TEST_F(ServerTest, Http400HtmlError)
   using namespace TestingOfHtmlResponses;
   const std::vector<TestContentIn400HtmlResponse> testData{
     { /* url */ "/ROOT%23%3F/search",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search" } } }, { "p" : { "msgid" : "too-many-books", "params" : { "LIMIT" : "3", "NB_BOOKS" : "4" } } } ] })" &&
       expected_body== R"(
     <h1>Invalid request</h1>
     <p>
@@ -876,6 +929,7 @@ TEST_F(ServerTest, Http400HtmlError)
     </p>
 )"  },
     { /* url */ "/ROOT%23%3F/search?content=zimfile",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?content=zimfile" } } }, { "p" : { "msgid" : "no-query", "params" : { } } } ] })" &&
       expected_body==R"(
     <h1>Invalid request</h1>
     <p>
@@ -886,6 +940,7 @@ TEST_F(ServerTest, Http400HtmlError)
     </p>
 )"  },
     { /* url */ "/ROOT%23%3F/search?content=non-existing-book&pattern=asdfqwerty",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?content=non-existing-book&pattern=asdfqwerty" } } }, { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "non-existing-book" } } } ] })" &&
       expected_body==R"(
     <h1>Invalid request</h1>
     <p>
@@ -896,6 +951,7 @@ TEST_F(ServerTest, Http400HtmlError)
     </p>
 )"  },
     { /* url */ "/ROOT%23%3F/search?content=non-existing-book&pattern=a\"<script foo>",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?content=non-existing-book&pattern=a%22%3Cscript%20foo%3E" } } }, { "p" : { "msgid" : "no-such-book", "params" : { "BOOK_NAME" : "non-existing-book" } } } ] })" &&
       expected_body==R"(
     <h1>Invalid request</h1>
     <p>
@@ -908,6 +964,7 @@ TEST_F(ServerTest, Http400HtmlError)
     // There is a flaw in our way to handle query string, we cannot differenciate
     // between `pattern` and `pattern=`
     { /* url */ "/ROOT%23%3F/search?books.filter.lang=eng&pattern",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?books.filter.lang=eng&pattern" } } }, { "p" : { "msgid" : "no-query", "params" : { } } } ] })" &&
       expected_body==R"(
     <h1>Invalid request</h1>
     <p>
@@ -918,6 +975,7 @@ TEST_F(ServerTest, Http400HtmlError)
     </p>
 )"  },
     { /* url */ "/ROOT%23%3F/search?pattern=foo",
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?pattern=foo" } } }, { "p" : { "msgid" : "too-many-books", "params" : { "LIMIT" : "3", "NB_BOOKS" : "4" } } } ] })" &&
       expected_body==R"(
     <h1>Invalid request</h1>
     <p>
@@ -927,6 +985,20 @@ TEST_F(ServerTest, Http400HtmlError)
       Too many books requested (4) where limit is 3
     </p>
 )"  },
+
+    // Testing of translation
+    { /* url */ "/ROOT%23%3F/search?content=zimfile&userlang=test",
+      expected_page_title=="[I18N TESTING] Invalid request ($400 fine must be paid)" &&
+      expected_kiwix_response_data==R"({ "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : "/ROOT%23%3F/search?content=zimfile&userlang=test" } } }, { "p" : { "msgid" : "no-query", "params" : { } } } ] })" &&
+      expected_body==R"(
+    <h1>[I18N TESTING] -400 karma for an invalid request</h1>
+    <p>
+      [I18N TESTING] Invalid URL: "/ROOT%23%3F/search?content=zimfile&userlang=test"
+    </p>
+    <p>
+      [I18N TESTING] Kiwix can read your thoughts but it is against GDPR. Please provide your query explicitly.
+    </p>
+)"  },
   };
 
   for ( const auto& t : testData ) {
@@ -1023,7 +1095,10 @@ TEST_F(ServerTest, 500)
   <head>
     <meta content="text/html;charset=UTF-8" http-equiv="content-type" />
     <title>Internal Server Error</title>
-
+    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = )" + ERROR_HTML_TEMPLATE_JS_STRING + R"(;
+      window.KIWIX_RESPONSE_DATA = { "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "500-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "500-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "500-page-text", "params" : { } } }, { "p" : { "msgid" : "non-translated-text", "params" : { "MSG" : "Entry redirect_loop.html is a redirect entry." } } } ] };
+    </script>
   </head>
   <body>
     <h1>Internal Server Error</h1>
@@ -1041,6 +1116,7 @@ TEST_F(ServerTest, 500)
   const auto r = zfs1_->GET("/ROOT%23%3F/content/poor/A/redirect_loop.html");
   EXPECT_EQ(r->status, 500);
   EXPECT_EQ(r->body, expectedBody);
+  EXPECT_EQ(r->get_header_value("Content-Type"), "text/html; charset=utf-8");
   }
 }
 
@@ -1050,106 +1126,174 @@ TEST_F(ServerTest, UserLanguageList)
   EXPECT_EQ(r->body,
 R"EXPECTEDRESPONSE(const uiLanguages = [
   {
-    "الإنجليزية": "ar"
+    "iso_code": "ar",
+    "self_name": "الإنجليزية",
+    "translation_count": 25
   },
   {
-    "বাংলা": "bn"
+    "iso_code": "bn",
+    "self_name": "বাংলা",
+    "translation_count": 12
   },
   {
-    "Čeština": "cs"
+    "iso_code": "cs",
+    "self_name": "Čeština",
+    "translation_count": 25
   },
   {
-    "Deutsch": "de"
+    "iso_code": "de",
+    "self_name": "Deutsch",
+    "translation_count": 49
   },
   {
-    "English": "en"
+    "iso_code": "en",
+    "self_name": "English",
+    "translation_count": 58
   },
   {
-    "español": "es"
+    "iso_code": "es",
+    "self_name": "español",
+    "translation_count": 48
   },
   {
-    "suomi": "fi"
+    "iso_code": "fi",
+    "self_name": "suomi",
+    "translation_count": 22
   },
   {
-    "Français": "fr"
+    "iso_code": "fr",
+    "self_name": "Français",
+    "translation_count": 52
   },
   {
-    "עברית": "he"
+    "iso_code": "he",
+    "self_name": "עברית",
+    "translation_count": 52
   },
   {
-    "हिन्दी": "hi"
+    "iso_code": "hi",
+    "self_name": "हिन्दी",
+    "translation_count": 49
   },
   {
-    "Հայերեն": "hy"
+    "iso_code": "hy",
+    "self_name": "Հայերեն",
+    "translation_count": 15
   },
   {
-    "interlingua": "ia"
+    "iso_code": "ia",
+    "self_name": "interlingua",
+    "translation_count": 49
   },
   {
-    "italiano": "it"
+    "iso_code": "it",
+    "self_name": "italiano",
+    "translation_count": 29
   },
   {
-    "日本語": "ja"
+    "iso_code": "ja",
+    "self_name": "日本語",
+    "translation_count": 26
   },
   {
-    "한국어": "ko"
+    "iso_code": "ko",
+    "self_name": "한국어",
+    "translation_count": 13
   },
   {
-    "kurdî": "ku-latn"
+    "iso_code": "ku-latn",
+    "self_name": "kurdî",
+    "translation_count": 26
   },
   {
-    "Lëtzebuergesch": "lb"
+    "iso_code": "lb",
+    "self_name": "Lëtzebuergesch",
+    "translation_count": 22
   },
   {
-    "македонски": "mk"
+    "iso_code": "mk",
+    "self_name": "македонски",
+    "translation_count": 52
   },
   {
-    "Bahasa Melayu": "ms"
+    "iso_code": "ms",
+    "self_name": "Bahasa Melayu",
+    "translation_count": 14
   },
   {
-    "Nederlands": "nl"
+    "iso_code": "nl",
+    "self_name": "Nederlands",
+    "translation_count": 49
   },
   {
-    "ߒߞߏ": "nqo"
+    "iso_code": "nqo",
+    "self_name": "ߒߞߏ",
+    "translation_count": 43
   },
   {
-    "ଓଡ଼ିଆ": "or"
+    "iso_code": "or",
+    "self_name": "ଓଡ଼ିଆ",
+    "translation_count": 49
   },
   {
-    "Polski": "pl"
+    "iso_code": "pl",
+    "self_name": "Polski",
+    "translation_count": 24
   },
   {
-    "русский": "ru"
+    "iso_code": "ru",
+    "self_name": "русский",
+    "translation_count": 45
   },
   {
-    "Sardu": "sc"
+    "iso_code": "sc",
+    "self_name": "Sardu",
+    "translation_count": 49
   },
   {
-    "slovenčina": "sk"
+    "iso_code": "sk",
+    "self_name": "slovenčina",
+    "translation_count": 25
   },
   {
-    "سرائیکی": "skr-arab"
+    "iso_code": "skr-arab",
+    "self_name": "سرائیکی",
+    "translation_count": 20
   },
   {
-    "slovenščina": "sl"
+    "iso_code": "sl",
+    "self_name": "slovenščina",
+    "translation_count": 52
   },
   {
-    "Shqip": "sq"
+    "iso_code": "sq",
+    "self_name": "Shqip",
+    "translation_count": 49
   },
   {
-    "Svenska": "sv"
+    "iso_code": "sv",
+    "self_name": "Svenska",
+    "translation_count": 52
   },
   {
-    "ఇంగ్లీషు": "te"
+    "iso_code": "te",
+    "self_name": "ఇంగ్లీషు",
+    "translation_count": 49
   },
   {
-    "Türkçe": "tr"
+    "iso_code": "tr",
+    "self_name": "Türkçe",
+    "translation_count": 25
   },
   {
-    "英语": "zh-hans"
+    "iso_code": "zh-hans",
+    "self_name": "英语",
+    "translation_count": 16
   },
   {
-    "繁體中文": "zh-hant"
+    "iso_code": "zh-hant",
+    "self_name": "繁體中文",
+    "translation_count": 52
   }
 ])EXPECTEDRESPONSE");
 }
@@ -1161,7 +1305,6 @@ TEST_F(ServerTest, UserLanguageControl)
     const std::string description;
     const std::string url;
     const std::string acceptLanguageHeader;
-    const char* const requestCookie; // Cookie: header of the request
     const std::string expectedH1;
 
     operator TestContext() const
@@ -1172,64 +1315,45 @@ TEST_F(ServerTest, UserLanguageControl)
           {"acceptLanguageHeader", acceptLanguageHeader},
       };
 
-      if ( requestCookie ) {
-        ctx.push_back({"requestCookie", requestCookie});
-      }
-
       return ctx;
     }
   };
 
-  const char* const NO_COOKIE = nullptr;
-
   const TestData testData[] = {
     {
       "Default user language is English",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
       /*Accept-Language:*/ "",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "Not Found"
     },
     {
       "userlang URL query parameter is respected",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article?userlang=en",
       /*Accept-Language:*/ "",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "Not Found"
     },
     {
       "userlang URL query parameter is respected",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article?userlang=test",
       /*Accept-Language:*/ "",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
     },
     {
       "'Accept-Language: *' is handled",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
       /*Accept-Language:*/ "*",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "Not Found"
     },
     {
       "Accept-Language: header is respected",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
       /*Accept-Language:*/ "test",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
     },
-    {
-      "userlang cookie is ignored",
-      /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
-      /*Accept-Language:*/ "",
-      /*Request Cookie:*/       "userlang=test",
-      /* expected <h1> */ "Not Found"
-    },
     {
       "userlang query parameter takes precedence over Accept-Language",
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article?userlang=en",
       /*Accept-Language:*/ "test",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "Not Found"
     },
     {
@@ -1238,7 +1362,6 @@ TEST_F(ServerTest, UserLanguageControl)
       // with quality values) the most suitable language is selected.
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
       /*Accept-Language:*/ "test;q=0.9, en;q=0.2",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
     },
     {
@@ -1247,7 +1370,6 @@ TEST_F(ServerTest, UserLanguageControl)
       // with quality values) the most suitable language is selected.
       /*url*/ "/ROOT%23%3F/content/zimfile/invalid-article",
       /*Accept-Language:*/ "test;q=0.2, en;q=0.9",
-      /*Request Cookie:*/       NO_COOKIE,
       /* expected <h1> */ "Not Found"
     },
   };
@@ -1259,9 +1381,6 @@ TEST_F(ServerTest, UserLanguageControl)
     if ( !t.acceptLanguageHeader.empty() ) {
       headers.insert({"Accept-Language", t.acceptLanguageHeader});
     }
-    if ( t.requestCookie ) {
-      headers.insert({"Cookie", t.requestCookie});
-    }
     const auto r = zfs1_->GET(t.url.c_str(), headers);
     EXPECT_FALSE(r->has_header("Set-Cookie"));
     std::regex_search(r->body, h1Match, h1Regex);
@@ -1958,8 +2077,7 @@ TEST_F(ServerTest, viewerSettings)
 R"(const viewerSettings = {
   toolbarEnabled:       false,
   linkBlockingEnabled:  false,
-  libraryButtonEnabled: false,
-  defaultUserLanguage:  "en"
+  libraryButtonEnabled: false
 }
 )");
   }
@@ -1970,8 +2088,7 @@ R"(const viewerSettings = {
 R"(const viewerSettings = {
   toolbarEnabled:       false,
   linkBlockingEnabled:  true,
-  libraryButtonEnabled: false,
-  defaultUserLanguage:  "en"
+  libraryButtonEnabled: false
 }
 )");
   }
@@ -1982,8 +2099,7 @@ R"(const viewerSettings = {
 R"(const viewerSettings = {
   toolbarEnabled:       true,
   linkBlockingEnabled:  false,
-  libraryButtonEnabled: false,
-  defaultUserLanguage:  "en"
+  libraryButtonEnabled: false
 }
 )");
   }
@@ -1994,47 +2110,7 @@ R"(const viewerSettings = {
 R"(const viewerSettings = {
   toolbarEnabled:       true,
   linkBlockingEnabled:  false,
-  libraryButtonEnabled: true,
-  defaultUserLanguage:  "en"
-}
-)");
-  }
-
-  {
-    resetServer(ZimFileServer::WITH_TASKBAR_AND_LIBRARY_BUTTON);
-    const Headers headers{ {"Accept-Language", "fr"} };
-    ASSERT_EQ(zfs1_->GET("/ROOT%23%3F/viewer_settings.js", headers)->body,
-R"(const viewerSettings = {
-  toolbarEnabled:       true,
-  linkBlockingEnabled:  false,
-  libraryButtonEnabled: true,
-  defaultUserLanguage:  "fr"
-}
-)");
-  }
-
-  {
-    resetServer(ZimFileServer::WITH_TASKBAR_AND_LIBRARY_BUTTON);
-    const Headers headers{ {"Accept-Language", "test;q=0.2, en;q=0.9"} };
-    ASSERT_EQ(zfs1_->GET("/ROOT%23%3F/viewer_settings.js", headers)->body,
-R"(const viewerSettings = {
-  toolbarEnabled:       true,
-  linkBlockingEnabled:  false,
-  libraryButtonEnabled: true,
-  defaultUserLanguage:  "en"
-}
-)");
-  }
-
-  {
-    resetServer(ZimFileServer::WITH_TASKBAR_AND_LIBRARY_BUTTON);
-    const Headers headers{ {"Accept-Language", "test;q=0.9, en;q=0.2"} };
-    ASSERT_EQ(zfs1_->GET("/ROOT%23%3F/viewer_settings.js", headers)->body,
-R"(const viewerSettings = {
-  toolbarEnabled:       true,
-  linkBlockingEnabled:  false,
-  libraryButtonEnabled: true,
-  defaultUserLanguage:  "test"
+  libraryButtonEnabled: true
 }
 )");
   }

test/server_search.cpp

@@ -113,7 +113,7 @@ std::string makeSearchResultsHtml(const std::string& pattern,
       }
 
     </style>
-    <title>Search: %PATTERN%</title>
+    <title>%USERLANGMARKER%Search: %PATTERN%</title>
   </head>
   <body bgcolor="white">
     <div class="header">
@@ -173,8 +173,8 @@ struct SearchResult
       + "              " + title + "\n"
       + "            </a>\n"
       + "              <cite>" + snippet + "</cite>\n"
-      + "              <div class=\"book-title\">from " + bookTitle + "</div>\n"
-      + "              <div class=\"informations\">" + wordCount + " words</div>\n";
+      + "              <div class=\"book-title\">from %USERLANGMARKER%" + bookTitle + "</div>\n"
+      + "              <div class=\"informations\">" + wordCount + " %USERLANGMARKER%words</div>\n";
   }
 
   std::string getXml() const
@@ -737,26 +737,16 @@ struct TestData
 
   std::string expectedHtmlHeader() const
   {
-    if ( totalResultCount == 0 ) {
-      return "\n        No results were found for <b>\"" + getPattern() + "\"</b>";
-    }
-
-    std::string header = R"(  Results
-        <b>
-          FIRSTRESULT-LASTRESULT
-        </b> of <b>
-          RESULTCOUNT
-        </b> for <b>
-          "PATTERN"
-        </b>
-      )";
+    std::string header = totalResultCount == 0
+                       ? R"(No results were found for <b>"PATTERN"</b>)"
+                       : R"(Results <b>FIRSTRESULT-LASTRESULT</b> of <b>RESULTCOUNT</b> for <b>"PATTERN"</b>)";
 
     const size_t lastResultIndex = std::min(totalResultCount, firstResultIndex + results.size() - 1);
     header = replace(header, "FIRSTRESULT", std::to_string(firstResultIndex));
     header = replace(header, "LASTRESULT",  std::to_string(lastResultIndex));
     header = replace(header, "RESULTCOUNT", std::to_string(totalResultCount));
     header = replace(header, "PATTERN",     getPattern());
-    return header;
+    return "%USERLANGMARKER%" + header;
   }
 
   std::string expectedHtmlResultsString() const
@@ -800,12 +790,18 @@ struct TestData
 
   std::string expectedHtml() const
   {
-    return makeSearchResultsHtml(
-             getPattern(),
-             expectedHtmlHeader(),
-             expectedHtmlResultsString(),
-             expectedHtmlFooter()
+    const std::string html = makeSearchResultsHtml(
+                                 getPattern(),
+                                 expectedHtmlHeader(),
+                                 expectedHtmlResultsString(),
+                                 expectedHtmlFooter()
     );
+
+    const std::string userlangMarker = extractQueryValue("userlang") == "test"
+                                     ? "[I18N TESTING] "
+                                     : "";
+
+    return replace(html, "%USERLANGMARKER%", userlangMarker);
   }
 
     std::string expectedXmlHeader() const
@@ -824,7 +820,8 @@ struct TestData
     />)";
 
       const auto realResultsPerPage = resultsPerPage?resultsPerPage:25;
-      const auto url = makeUrl(query + "&format=xml", firstResultIndex, realResultsPerPage);
+      const auto cleanedUpQuery = replace(query, "&userlang=test", "");
+      const auto url = makeUrl(cleanedUpQuery + "&format=xml", firstResultIndex, realResultsPerPage);
       header = replace(header, "URL", replace(url, "&", "&amp;"));
       header = replace(header, "FIRSTRESULT", std::to_string(firstResultIndex));
       header = replace(header, "ITEMCOUNT",  std::to_string(realResultsPerPage));
@@ -931,6 +928,17 @@ TEST(ServerSearchTest, searchResults)
       /* pagination */       {}
     },
 
+    {
+      /* query */          "pattern=velomanyunkan&books.id=" RAYCHARLESZIMID
+                           "&userlang=test",
+      /* start */            -1,
+      /* resultsPerPage */   0,
+      /* totalResultCount */ 0,
+      /* firstResultIndex */ 1,
+      /* results */          {},
+      /* pagination */       {}
+    },
+
     {
       /* query */          "pattern=razaf&books.id=" RAYCHARLESZIMID,
       /* start */            -1,
@@ -1037,6 +1045,17 @@ TEST(ServerSearchTest, searchResults)
       /* pagination */ {}
     },
 
+    {
+      /* query */          "pattern=jazz&books.id=" RAYCHARLESZIMID
+                           "&userlang=test",
+      /* start */            -1,
+      /* resultsPerPage */   100,
+      /* totalResultCount */ 44,
+      /* firstResultIndex */ 1,
+      /* results */ LARGE_SEARCH_RESULTS,
+      /* pagination */ {}
+    },
+
     {
       /* query */          "pattern=jazz&books.id=" RAYCHARLESZIMID,
       /* start */            -1,
@@ -1509,7 +1528,10 @@ std::string expectedConfusionOfTonguesErrorHtml(std::string url)
   <head>
     <meta content="text/html;charset=UTF-8" http-equiv="content-type" />
     <title>Invalid request</title>
-
+    <script>
+      window.KIWIX_RESPONSE_TEMPLATE = )" + ERROR_HTML_TEMPLATE_JS_STRING + R"(;
+      window.KIWIX_RESPONSE_DATA = { "CSS_URL" : false, "PAGE_HEADING" : { "msgid" : "400-page-heading", "params" : { } }, "PAGE_TITLE" : { "msgid" : "400-page-title", "params" : { } }, "details" : [ { "p" : { "msgid" : "invalid-request", "params" : { "url" : ")" + url + R"(" } } }, { "p" : { "msgid" : "confusion-of-tongues", "params" : { } } } ] };
+    </script>
   </head>
   <body>
     <h1>Invalid request</h1>

test/server_testing_tools.h

@@ -190,3 +190,5 @@ protected:
     zfs1_.reset();
   }
 };
+
+static const std::string ERROR_HTML_TEMPLATE_JS_STRING = R"("<!DOCTYPE html>\n<html xmlns="http://www.w3.org/1999/xhtml">\n  <head>\n    <meta content="text/html;charset=UTF-8" http-equiv="content-type" />\n    <title>{{PAGE_TITLE}}</title>\n{{#CSS_URL}}\n    <link type="text/css" href="{{{CSS_URL}}}" rel="Stylesheet" />\n{{/CSS_URL}}{{#KIWIX_RESPONSE_DATA}}    <script>\n      window.KIWIX_RESPONSE_TEMPLATE = "{{KIWIX_RESPONSE_TEMPLATE}}";\n      window.KIWIX_RESPONSE_DATA = {{{KIWIX_RESPONSE_DATA}}};\n    </script>{{/KIWIX_RESPONSE_DATA}}\n  </head>\n  <body>\n    <h1>{{PAGE_HEADING}}</h1>\n{{#details}}\n    <p>\n      {{{p}}}\n    </p>\n{{/details}}\n  </body>\n</html>\n")";