Merge branch 'dev' into merge-crops

I've added a 'Merge Duplicates' button to the wrangle page, which links to the new merge page.

It contains a form with two fields for the master and duplicate crop slugs.

This method moves all associated objects from a duplicate crop to the master crop and then deletes the duplicate crop. The entire operation is wrapped in a database transaction.

I've updated the `merge` action in `crops_controller.rb` to prevent a crop from being merged with itself. The implementation of the controller action is now complete.

app/controllers/crops_controller.rb

@@ -39,6 +39,30 @@ class CropsController < ApplicationController
     respond_with @crops
   end
 
+  def merge
+    authorize! :merge, Crop
+    if request.post?
+      master_crop = Crop.find_by(slug: params[:master_crop_slug])
+      duplicate_crop = Crop.find_by(slug: params[:duplicate_crop_slug])
+
+      if master_crop && duplicate_crop
+        if master_crop == duplicate_crop
+          flash[:alert] = "You cannot merge a crop with itself."
+          render :merge
+        else
+          master_crop.merge_with(duplicate_crop)
+          flash[:notice] = "Successfully merged #{duplicate_crop.name} into #{master_crop.name}."
+          redirect_to wrangle_crops_path
+        end
+      else
+        flash[:alert] = "Could not find one of the crops."
+        render :merge
+      end
+    else
+      # GET request, just render the form
+    end
+  end
+
   def gbif
     @crop = Crop.find(params[:crop_slug])
     @crop.update_gbif_data!

app/models/ability.rb

@@ -75,6 +75,7 @@ class Ability
     # only crop wranglers can create/edit/destroy crops
     if member.role? :crop_wrangler
       can :wrangle, Crop
+      can :merge, Crop
       can :manage, Crop
       can :manage, CropCompanion
       can :manage, ScientificName

app/models/crop.rb

@@ -170,6 +170,25 @@ class Crop < ApplicationRecord
     (companions + parent.all_companions).uniq
   end
 
+  def merge_with(other_crop)
+    Crop.transaction do
+      other_crop.alternate_names.update_all(crop_id: id)
+      other_crop.scientific_names.update_all(crop_id: id)
+      other_crop.plantings.update_all(crop_id: id)
+      other_crop.seeds.update_all(crop_id: id)
+      other_crop.harvests.update_all(crop_id: id)
+      other_crop.photo_associations.update_all(crop_id: id)
+      other_crop.varieties.update_all(parent_id: id)
+      other_crop.crop_posts.update_all(crop_id: id)
+
+      # Companions can be crop_a or crop_b
+      CropCompanion.where(crop_a_id: other_crop.id).update_all(crop_a_id: id)
+      CropCompanion.where(crop_b_id: other_crop.id).update_all(crop_b_id: id)
+
+      other_crop.destroy
+    end
+  end
+
   before_destroy :destroy_reverse_companionships
 
   private

app/views/crops/merge.html.haml

@@ -0,0 +1,14 @@
+- content_for :title, "Merge Crops"
+
+%h1 Merge Crops
+
+= form_tag merge_crops_path, method: :post do
+  .form-group
+    = label_tag :master_crop_slug, "Master Crop (the one to keep)"
+    = text_field_tag :master_crop_slug, nil, class: 'form-control'
+
+  .form-group
+    = label_tag :duplicate_crop_slug, "Duplicate Crop (the one to delete)"
+    = text_field_tag :duplicate_crop_slug, nil, class: 'form-control'
+
+  = submit_tag "Merge", class: 'btn btn-primary'

app/views/crops/wrangle.html.haml

@@ -4,6 +4,7 @@
 
 %nav.nav
   = link_to "Full crop hierarchy", hierarchy_crops_path, class: 'nav-link'
+  = link_to "Merge Duplicates", merge_crops_path, class: 'btn'
   = link_to "Add Crop", new_crop_path, class: 'btn'
 
 %section.crop_wranglers

config/routes.rb

@@ -88,6 +88,8 @@ Rails.application.routes.draw do
     collection do
       get 'requested'
       get 'wrangle'
+      get 'merge'
+      post 'merge'
       get 'hierarchy'
       get 'search'
       get 'data_improvement'