Display crop hierarchy (recursively!)

app/controllers/crops_controller.rb

@@ -27,6 +27,7 @@ class CropsController < ApplicationController
 
   # GET /crops/hierarchy
   def hierarchy
+    @crops = Crop.toplevel
     respond_to do |format|
       format.html
     end

app/views/crops/_hierarchy.html.haml

@@ -0,0 +1,7 @@
+%ul
+  - display_crops.each do |c|
+    %li
+      = link_to c, c
+      - if c.varieties.present?
+        - c.varieties.each do |v|
+          = render :partial => 'hierarchy', :locals => { :display_crops => [ v ] }

app/views/crops/hierarchy.html.haml

@@ -4,3 +4,5 @@
   This page shows the hierarchical tree of all crops in our
   = succeed "." do
     = link_to "crops database", crops_path
+
+= render :partial => "hierarchy", :locals => { :display_crops => @crops }

spec/views/crops/hierarchy.html.haml_spec.rb

@@ -0,0 +1,15 @@
+require 'spec_helper'
+
+describe "crops/hierarchy" do
+  before(:each) do
+    controller.stub(:current_user) { nil }
+    @tomato = FactoryGirl.create(:tomato)
+    @roma = FactoryGirl.create(:crop, :system_name => 'Roma tomato', :parent => @tomato)
+    assign(:crops, [@tomato, @roma])
+    render
+  end
+
+  it "shows crop hierarchy" do
+    assert_select "ul>li>ul>li", :text => @roma.system_name
+  end
+end