Use fragment caching for thumbnails

app/models/asciicast.rb

@@ -23,6 +23,10 @@ class Asciicast < ActiveRecord::Base
     update_all(:user_id => user.id, :user_token => nil)
   end
 
+  def self.cache_key
+    Digest::MD5.hexdigest "#{scoped.maximum(:updated_at).try(:to_i)}-#{scoped.count}"
+  end
+
   def meta=(file)
     data = JSON.parse(file.tempfile.read)
 

app/views/asciicasts/_preview.html.erb

@@ -1,16 +1,18 @@
-<div class="presentation">
-  <%= link_to preview, :class => 'preview-link' do %>
-    <div class="play-button"><div class="arrow">►</div></div>
-    <pre class="preview"><%= preview.thumbnail(28, 9) %></pre>
-  <% end -%>
+<% cache ['thumbnail', preview] do %>
+  <div class="presentation">
+    <%= link_to preview, :class => 'preview-link' do %>
+      <div class="play-button"><div class="arrow">►</div></div>
+      <pre class="preview"><%= preview.thumbnail(28, 9) %></pre>
+    <% end -%>
 
-  <div class="info">
-    <h3>
-      <%= link_to preview.smart_title, preview %>
-    </h3>
+    <div class="info">
+      <h3>
+        <%= link_to preview.smart_title, preview %>
+      </h3>
 
-    <p class="date">
-      <%= preview.created_at %> ago by <%= preview.author_profile_link %>
-    </p>
+      <p class="date">
+        <%= preview.created_at %> ago by <%= preview.author_profile_link %>
+      </p>
+    </div>
   </div>
-</div>
+<% end -%>

app/views/asciicasts/_previews.html.erb

@@ -1,3 +1,5 @@
 <div class="presentations">
-  <%= render :partial => 'asciicasts/preview', :collection => @asciicasts %>
+  <% cache @asciicasts do -%>
+    <%= render :partial => 'asciicasts/preview', :collection => @asciicasts %>
+  <% end -%>
 </div>