category getter, will need caching

apps/addons/models.py

@@ -373,6 +373,9 @@ class Addon(amo.models.OnChangeMixin, amo.models.ModelBase):
     def reviews(self):
         return Review.objects.filter(addon=self, reply_to=None)
 
+    def get_category(self, app):
+        return self.categories.filter(application=app)[0]
+
     def language_ascii(self):
         return settings.LANGUAGES[translation.to_language(self.default_locale)]
 

apps/addons/templates/addons/impala/addon_grid.html

@@ -9,13 +9,7 @@
         </div>
         <div class="summary">
           <h3>{{ addon.name }}</h3>
-          {% with categories = addon.categories.filter(application=APP.id) %}
-            {% if categories %}
-              <div class="category" class="more-info">
-                {{ categories[0] }}
-              </div>
-            {% endif %}
-          {% endwith %}
+          <div class="category" class="more-info">{{ addon.get_category(APP.id) }}</div>
           <div class="rating">&#x2605;&#x2605;&#x2605;&#x2605;&#x2605;</div>
         </div>
       </a>