Adds first 150 chars of content as meta description, if no page.description specified. Fixes #162

.themes/classic/source/_includes/head.html

@@ -6,18 +6,16 @@
   <meta charset="utf-8">
   <title>{% if page.title %}{{page.title}} - {% endif %}{{site.title}}</title>
   <meta name="author" content="{{site.author}}">
-  {% if page.description %}
-    <meta name="description" content="{{page.description}}"/>
-  {% endif %}
+
+  {% capture description %}{% if page.description %}{{ page.description }}{% else %}{{ content | raw_content }}{% endif %}{% endcapture %}
+  <meta name="description" content="{{ description | strip_newlines | strip_html | truncate:150 }}">
+  {% if page.keywords %}<meta name="keywords" content="{{ page.keywords }}">{% endif %}
 
   <!-- http://t.co/dKP3o1e -->
   <meta name="HandheldFriendly" content="True">
   <meta name="MobileOptimized" content="320">
   <meta name="viewport" content="width=device-width, initial-scale=1">
 
-  {% if page.keywords %}
-    <meta name="keywords" content="{{page.keywords}}"/>
-  {% endif %}
   {% capture canonical %}{{ site.url }}{% if site.permalink contains '.html' %}{{ page.url }}{% else %}{{ page.url | remove:'index.html' }}{% endif %}{% endcapture %}
   <link rel="canonical" href="{{ canonical }}">
   <link href="{{ root_url }}/favicon.png" rel="shortcut icon" />

plugins/octopress_filters.rb

@@ -56,6 +56,13 @@ module OctopressLiquidFilters
     end
   end
 
+  # Extracts raw content DIV from template, used for page description as {{ content }}
+  # contains complete sub-template code on main page level
+  def raw_content(input)
+    /.<div class="entry-content">(?<content>[\s\S]*?)<\/div>\s*<\/article>/ =~ input
+    return (content.nil?) ? input : content
+  end
+
   # Replaces relative urls with full urls
   def expand_urls(input, url='')
     url ||= '/'