just get the size of the query for profile page (bug 860407)

Author: cvan

apps/users/models.py

@@ -174,6 +174,12 @@ def addons_listed(self):
         return self.addons.reviewed().exclude(type=amo.ADDON_WEBAPP).filter(
             addonuser__user=self, addonuser__listed=True)
 
+    @amo.cached_property
+    def num_addons_listed(self):
+        """Number of public add-ons this user is listed as author of."""
+        return self.addons.reviewed().exclude(type=amo.ADDON_WEBAPP).filter(
+            addonuser__user=self, addonuser__listed=True).count()
+
     @amo.cached_property
     def apps_listed(self):
         """Public apps this user is listed as author of."""

apps/users/templates/users/vcard.html

@@ -39,7 +39,7 @@
         {{ _('Number of add-ons developed') }}
       </th>
       <td class="num-addons">
-        {% with num=profile.addons_listed|length %}
+        {% with num=profile.num_addons_listed %}
           {% if num == 0 %}
              {{ _('{0} add-ons')|f(num) }}
           {% else %}