# HG changeset patch
# User Brian Neal <bgneal@gmail.com>
# Date 1298340686 0
# Node ID a1bf6cf4972002c526597c2fef7cd9eb2e4fa4a3
# Parent  5453aedf95fda8787f0e6af1f6ba7e4a8b2e092c
Modified the implementation of the avatar tag to look for an attribute 'user_profile' on the user object. If present, this is assumed to be the profile. This improves the performance of the member list and some forum views.

diff -r 5453aedf95fd -r a1bf6cf49720 gpp/bio/templatetags/avatar_tags.py
--- a/gpp/bio/templatetags/avatar_tags.py	Sun Feb 20 22:12:06 2011 +0000
+++ b/gpp/bio/templatetags/avatar_tags.py	Tue Feb 22 02:11:26 2011 +0000
@@ -1,34 +1,60 @@
 """
-Template tags for the bio application. 
+Template tags for the bio application.
 """
 from django import template
 from django.conf import settings
 from django.core.cache import cache
 
+from bio.models import UserProfile
+
+
 register = template.Library()
 
 
+def get_img_info(profile=None):
+    """
+    This function returns a 3-tuple: (url, width, height) for a user profile
+    avatar. If the profile is None or the profile doesn't contain a valid
+    avatar, info for the default avatar is returned.
+
+    """
+    if profile is None or profile.avatar.name == '':
+        return (settings.AVATAR_DEFAULT_URL,
+                settings.MAX_AVATAR_SIZE_PIXELS,
+                settings.MAX_AVATAR_SIZE_PIXELS)
+    else:
+        return (profile.avatar.url,
+                profile.avatar.width,
+                profile.avatar.height)
+
+
 @register.simple_tag
 def avatar(user, align='bottom'):
-    """Returns the HTML for a user's avatar image."""
+    """
+    Returns the HTML for a user's avatar image.
 
-    # In the cache is stored a tuple containing info about the 
-    # avatar: (url, width, height)
-    cache_key = 'avatar_' + user.username
-    img_info = cache.get(cache_key)
-    if img_info is None:
-        try:
-            profile = user.get_profile()
-        except:
-            profile = None
-        if profile is None or profile.avatar.name == '':
-            img_info = (settings.AVATAR_DEFAULT_URL, 
-                settings.MAX_AVATAR_SIZE_PIXELS, 
-                settings.MAX_AVATAR_SIZE_PIXELS)
-        else:
-            img_info = (profile.avatar.url, profile.avatar.width,
-                profile.avatar.height)
-        cache.set(cache_key, img_info)
+    If the user object has an attribute 'user_profile', this is assumed to be
+    the user's profile that has been pre-fetched. Otherwise, the cache is
+    consulted to retrieve the avatar info for the user. If there is a cache
+    miss, only then will a get_profile() call be made.
+    """
+    # img_info is a tuple that contains info about the avatar:
+    # (url, width, height)
+
+    if hasattr(user, 'user_profile'):
+        img_info = get_img_info(user.user_profile)
+    else:
+        # try the cache
+        cache_key = 'avatar_' + user.username
+        img_info = cache.get(cache_key)
+        if img_info is None:
+            try:
+                profile = user.get_profile()
+            except UserProfile.DoesNotExist:
+                profile = None
+
+            img_info = get_img_info(profile)
+            cache.set(cache_key, img_info)
 
     alt = user.username
     title = alt