[#808] Add JournalsController#diff to diff a single field

app/controllers/journals_controller.rb

@@ -12,6 +12,8 @@
 # See doc/COPYRIGHT.rdoc for more details.
 #++
 
+require 'diff'
+
 class JournalsController < ApplicationController
   before_filter :find_journal, :only => [:edit, :diff]
   before_filter :find_issue, :only => [:new]
@@ -84,6 +86,21 @@ class JournalsController < ApplicationController
     end
   end
 
+  def diff
+    if valid_field?(params[:field])
+      from = @journal.changes[params[:field]][0]
+      to = @journal.changes[params[:field]][1]
+
+      @diff = Redmine::Helpers::Diff.new(to, from)
+      @issue = @journal.journaled
+      respond_to do |format|
+        format.html { }
+      end
+    else
+      render_404
+    end
+  end
+  
   private
 
   def find_journal
@@ -100,4 +117,9 @@ class JournalsController < ApplicationController
   rescue ActiveRecord::RecordNotFound
     render_404
   end
+
+  # Is this a valid field for diff'ing?
+  def valid_field?(field)
+    field.to_s.strip == "description"
+  end
 end

app/views/journals/diff.html.erb

@@ -0,0 +1,9 @@
+<p><%= authoring @journal.created_at, @journal.user, :label => :label_updated_time_by %></p>
+
+<div class="text-diff">
+<%= simple_format_without_paragraph @diff.to_html %>
+</div>
+
+<p><%= link_to(l(:button_back), issue_path(@issue)) %></p>
+
+<% html_title "#{@issue.tracker.name} ##{@issue.id}: #{@issue.subject}" %>

test/functional/journals_controller_test.rb

@@ -81,4 +81,68 @@ class JournalsControllerTest < ActionController::TestCase
     assert_select_rjs :show, "update"
   end
 
+  context "#diff" do
+    setup do
+      @request.session[:user_id] = 1
+      @issue = Issue.find(6)
+      @previous_description = @issue.description
+      @new_description = "New description"
+      
+      assert_difference("Journal.count") do
+        @issue.description = @new_description
+        assert @issue.save
+      end
+      @last_journal = @issue.last_journal
+    end
+    
+    context "without a valid journal" do
+      should "return a 404" do
+        get :diff, :id => '0'
+        assert_response :not_found
+      end
+    end
+
+
+    context "with no field parameter" do
+      should "return a 404" do
+        get :diff, :id => @last_journal.id
+        assert_response :not_found
+      end
+    end
+
+    context "for an invalid field" do
+      should "return a 404" do
+        get :diff, :id => @last_journal.id, :field => 'id'
+        assert_response :not_found
+      end
+    end
+
+    context "without permission to view_issues" do
+      should "return a 403" do
+        @request.session[:user_id] = 7
+        get :diff, :id => @last_journal.id, :field => 'description'
+
+        assert_response :forbidden
+      end
+      
+    end
+
+    context "with permission to view_issues" do
+      setup do
+        get :diff, :id => @last_journal.id, :field => 'description'
+      end
+      
+      should "create a diff" do
+        assert_not_nil assigns(:diff)
+        assert assigns(:diff).is_a?(Redmine::Helpers::Diff)
+      end
+
+      should "render an inline diff" do
+        assert_select "#content .text-diff"
+      end
+      
+    end
+      
+  end
+  
 end