=== Open Graph ===
Contributors: willnorris
Tags: social, opengraph, facebook
Tested up to: 3.3.1
Stable tag: 1.2

Add Open Graph metadata to your pages.

== Description ==

The [Open Graph Protocol][] defines a mechanism for adding additional metadata
to webpages to identify them as "social objects".  Most notably, this allows
for these pages to be used with the [Facebook Like Button][].  This plugin
inserts the Open Graph metadata into WordPress posts and pages, and provides a
simple extension mechansim for other plugins to override this data, or to
provide additional Open Graph data.

Note that this plugin does not actually add the Facebook Like Button to your
pages, or do anything directly with the Open Graph data.  It makes the data
available so that other services can do interesting things with it.

[Open Graph Protocol]: http://opengraphprotocol.org/
[Facebook Like Button]: http://developers.facebook.com/docs/reference/plugins/like


== Frequently Asked Questions ==

= How do I extend the Open Graph plugin? =

There are two main ways to provide Open Graph metadata from your plugin or
theme.  First, you can implement the filter for a specific property.  These
filters are of the form `opengraph_{name}` where {name} is the unqualified Open
Graph property name.  For example, if you have a plugin that defines a custom
post type named "movie", you could override the Open Graph 'type' property for
those posts using a function like:

  function my_og_type( $type ) {
      if ( get_post_type() == "movie" ) {
          $type = "movie";
      }
      return $type;
  }
  add_filter( 'opengraph_type', 'my_og_type' );

This will work for all of the core Open Graph properties.  However, if you want
to add a custom property, such as 'fb:admin', then you would need to hook into
the `opengraph_metadata` filter.  This filter is passed an associative array,
whose keys are the qualified Open Graph property names.  For example:

  function my_og_metadata( $metadata ) {
      $metadata['fb:admin'] = '12345,67890';
      return $metadata;
  }
  add_filter( 'opengraph_metadata', 'my_og_metadata' );

Note that it is your responsibility to make sure that the XML namespace is
registered for the prefix that you use.  To see one method for doing this, see
the `opengraph_add_namespace` function in the Open Graph plugin.


== Changelog ==

= version 1.2 (Feb 21, 2012) =
 - switch to newer RDFa prefix syntax rather than XML namespaces (props
   pfefferle) 

= version 1.1 (Nov 7, 2011) =
 - fix function undefined error when theme doesn't support post thumbnails

= version 1.0 (Apr 24, 2010) =
 - initial public release