render notes preview on server-side

app/assets/javascripts/application.js

@@ -18,7 +18,6 @@
 //= require chosen-jquery
 //= require raphael
 //= require branch-graph
-//= require Markdown.Converter
 //= require_tree .
 
 $(document).ready(function(){
@@ -76,15 +75,17 @@ $(document).ready(function(){
    *
    */
   $('#preview-link').on('click', function(e) {
-    var note = $('#note_note').val();
-    if (note.trim().length === 0) { note = 'Nothing to preview'; }
-    var converter = new Markdown.Converter();
-    var md_preview = converter.makeHtml(note);
-    $('#preview-note').html(md_preview);
+    $('#preview-note').text('Loading...');
 
     var previewLinkText = ($(this).text() == 'Preview' ? 'Edit' : 'Preview');
     $(this).text(previewLinkText);
 
+    var note = $('#note_note').val();
+    if (note.trim().length === 0) { note = 'Nothing to preview'; }
+    $.post($(this).attr('href'), {note: note}, function(data) {
+      $('#preview-note').html(data);
+    });
+
     $('#preview-note, #note_note').toggle();
     e.preventDefault();
   });

app/controllers/notes_controller.rb

@@ -33,6 +33,10 @@ class NotesController < ApplicationController
     end
   end
 
+  def preview
+    render :text => view_context.markdown(params[:note])
+  end
+
   protected
 
   def notes

app/views/notes/_form.html.haml

@@ -12,7 +12,7 @@
   %p.hint
     = link_to "Gitlab Markdown", help_markdown_path, :target => '_blank'
     is enabled.
-    = link_to 'Preview', '#', :id => 'preview-link'
+    = link_to 'Preview', preview_project_notes_path(@project), :id => 'preview-link'
 
   .row.note_advanced_opts.hide
     .span4

config/routes.rb

@@ -199,7 +199,11 @@ Gitlab::Application.routes.draw do
         get   :search
       end
     end
-    resources :notes, :only => [:index, :create, :destroy]
+    resources :notes, :only => [:index, :create, :destroy] do
+      collection do
+        post :preview
+      end
+    end
   end
   root :to => "dashboard#index"
 end