Ember support for parent categories

app/assets/javascripts/discourse/models/site.js

@@ -48,9 +48,18 @@ Discourse.Site.reopenClass(Discourse.Singleton, {
     var result = this._super(obj);
 
     if (result.categories) {
+      var byId = {}
       result.categories = _.map(result.categories, function(c) {
-        return Discourse.Category.create(c);
+        byId[c.id] = Discourse.Category.create(c);
+        return byId[c.id];
       });
+
+      // Associate the categories with their parents
+      result.categories.forEach(function (c) {
+        if (c.get('parent_category_id')) {
+          c.set('parentCategory', byId[c.get('parent_category_id')]);
+        }
+      })
     }
 
     if (result.trust_levels) {

app/serializers/basic_category_serializer.rb

@@ -10,6 +10,7 @@ class BasicCategorySerializer < ApplicationSerializer
              :topic_url,
              :hotness,
              :read_restricted,
-             :permission
+             :permission,
+             :parent_category_id
 
 end

test/javascripts/models/category_test.js

@@ -11,3 +11,4 @@ test('slugFor', function(){
   slugFor({id: 456}, "456-category", "It returns id-category for undefined slugs");
 
 });
+

test/javascripts/models/site_test.js

@@ -10,3 +10,27 @@ test('instance', function(){
   present(site.get('trustLevels'), "The instance has a list of trust levels");
 
 });
+
+test('create categories', function() {
+
+  var site = Discourse.Site.create({
+    categories: [{ id: 1234, name: 'Test'},
+                 { id: 3456, name: 'Test Subcategory', parent_category_id: 1234},
+                 { id: 3456, name: 'Invalid Subcategory', parent_category_id: 6666}]
+  });
+
+  var categories = site.get('categories');
+
+  present(categories, "The categories are present");
+  equal(categories.length, 3, "it loaded all three categories");
+
+  var parent = categories.findBy('id', 1234);
+  present(parent, "it loaded the parent category");
+  blank(parent.get('parentCategory'), 'it has no parent category');
+
+  var subcategory = categories.findBy('id', 3456);
+  present(subcategory, "it loaded the subcategory");
+  equal(subcategory.get('parentCategory'), parent, "it has associated the child with the parent");
+
+
+});