Use image if it exists

blog.rb

@@ -60,6 +60,7 @@ def url_base
       @date = source.date
       @formatted_date = source.formatted_date
       @blurb = source.blurb(200)
+      @image = source.image
 
       haml :post
     else

post.rb

@@ -71,4 +71,12 @@ def blurb(length=20)
       blurb = Sanitize.fragment(self.content)[0...(length-3)] + "..."
     end
   end
+
+  def image
+    doc = Nokogiri::HTML(self.content)
+    if img = doc.xpath('//img').first
+      src = img.attr('src')
+      URI(src).host ? src : "http://rarlindseysmash.com#{src}"
+    end
+  end
 end

views/layout.haml

@@ -8,10 +8,12 @@
   %head
     %meta{:charset=>"utf8"}
     %meta{:content=>"width=device-width, initial-scale=1, maximum-scale=1", :name=>"viewport"}
-    %meta{:name=>"twitter:card", :content=>"summary"}
+    %meta{:name=>"twitter:card", :content=> @image ? "summary_large_image" : "summary"}
     %meta{:name=>"twitter:site", :content=>"@lindeseybieda"}
     %meta{:name=>"twitter:title", :content=>title.sub("»", "»")}
     %meta{:name=>"twitter:description", :content=>description.strip}
+    - if @image
+      %meta{:name=>"twitter:image", :content=>@image}
 
     /[if lt IE 9]
       <script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>