Save images to disk for thumbnailing

.hgignore

@@ -8,3 +8,4 @@ syntax: glob
 local_settings.py
 static/cache/*
 static/photos/*
+static/drawings/*

core/templatetags/core_tags.py

@@ -16,6 +16,14 @@ def photo_for_user(user):
     """
     return "photos/%s" % user.id
 
+@register.filter
+def image_for_drawing(drawing):
+    """
+    Just returns the path to the drawing's image since we can't
+    combined values in a template to pass to the thumbnail tag.
+    """
+    return "drawings/%s" % drawing.id
+
 @register.simple_tag(takes_context=True)
 def load_in_progress(context):
     """

core/utils.py

@@ -1,4 +1,8 @@
 
+from os import mkdir
+from os.path import join, exists
+
+from django.conf import settings
 from django.contrib.auth.models import User
 from redis import Redis, ConnectionPool
 
@@ -69,6 +73,12 @@ def save(self, message):
                                          data=message[3].replace(" ", "+"))
         for user_id in redis.smembers(self.drawers_data_key):
             drawing.users.add(User.objects.get(id=user_id))
+        # Save image file for thumbnailing.
+        path = join(settings.MEDIA_ROOT, "drawings")
+        if not exists(path):
+            mkdir(path)
+        with open(join(path, str(drawing.id)), "wb") as f:
+            f.write(drawing.data.split(",", 1)[1].decode("base64"))
         return False
 
     def mousedown(self, message):

templates/list.html

@@ -1,5 +1,5 @@
 {% extends "base.html" %}
-{% load pagination_tags %}
+{% load thumbnail core_tags pagination_tags %}
 
 {% block body_class %}gallery{% endblock %}
 
@@ -8,7 +8,9 @@
 <div class="clearfix gallery-items">
     {% for drawing in drawings %}
     <div>
-        <a href="{% url view drawing.slug %}"><img src="{{ drawing.data }}">{{ drawing }}</a><br>
+        {% with drawing|image_for_drawing as drawing_image %}
+        <a href="{% url view drawing.slug %}"><img src="{% thumbnail drawing_image 152x71 %}">{{ drawing }}</a><br>
+        {% endwith %}
         {% include "rating.html" %}
     </div>
     {% endfor %}