The Open Graph protocol enables any web page to become a rich object in a social graph. For instance, this is used on Facebook to allow any web page to have the same functionality as any other object on Facebook.
Moreover, they use specal facebook widgets like: ‘Like’, ‘Share’, ‘Comments’ and ‘Recommend’ on their websites. The Open Graph Meta tags (or Facebook Open Graph API) that I am going to describe today will help you control over information to be shared on facebook (like url, title, image and description).
To turn your web pages into graph objects, you need to add basic metadata to your page. We've based the initial version of the protocol on RDFa which means that you'll place additional tags in the of your web page. The four required properties for every page are:
og:title - The title of your object as it should appear within the graph, e.g., "The Rock".
og:type - The type of your object, e.g., "video.movie". Depending on the type you specify, other properties may also be required.
og:image - An image URL which should represent your object within the graph.
og:url - The canonical URL of your object that will be used as its permanent ID in the graph, e.g., "http://www.imdb.com/title/tt0117500/".
As an example, the following is the Open Graph protocol markup for The Rock on IMDB:
<html prefix="og: http://ogp.me/ns#">
<head>
<title>The Rock (1996)</title>
<meta property="og:title" content="The Rock" />
<meta property="og:type" content="video.movie" />
<meta property="og:url" content="http://www.imdb.com/title/tt0117500/" />
<meta property="og:image" content="http://ia.media-imdb.com/images/rock.jpg" />
...
</head>
...
</html>The following properties are optional for any object and are generally recommended:
og:audio - A URL to an audio file to accompany this object.
og:description - A one to two sentence description of your object.
og:determiner - The word that appears before this object's title in a sentence. An enum of (a, an, the, "", auto). If auto is chosen, the consumer of your data should chose between "a" or "an". Default is "" (blank).
og:locale - The locale these tags are marked up in. Of the format language_TERRITORY. Default is en_US.
og:locale:alternate - An array of other locales this page is available in.
og:site_name - If your object is part of a larger web site, the name which should be displayed for the overall site. e.g., "IMDb".
og:video - A URL to a video file that complements this object.
For example (line-break solely for display purposes):
<meta property="og:audio" content="http://example.com/bond/theme.mp3" />
<meta property="og:description"
content="Sean Connery found fame and fortune as the
suave, sophisticated British agent, James Bond." />
<meta property="og:determiner" content="the" />
<meta property="og:locale" content="en_GB" />
<meta property="og:locale:alternate" content="fr_FR" />
<meta property="og:locale:alternate" content="es_ES" />
<meta property="og:site_name" content="IMDb" />
<meta property="og:video" content="http://example.com/bond/trailer.swf" />Some properties can have extra metadata attached to them. These are specified in the same way as other metadata with property and content, but the property will have extra :.
The og:image property has some optional structured properties:
> og:image:url - Identical to og:image.
> og:image:secure_url - An alternate url to use if the webpage requires HTTPS.
> og:image:type - A MIME type for this image.
> og:image:width - The number of pixels wide.
> og:image:height - The number of pixels high.
A full image example:
<meta property="og:image" content="http://example.com/ogp.jpg" />
<meta property="og:image:secure_url" content="https://secure.example.com/ogp.jpg" />
<meta property="og:image:type" content="image/jpeg" />
<meta property="og:image:width" content="400" />
<meta property="og:image:height" content="300" />The og:video tag has the identical tags as og:image. Here is an example:
<meta property="og:video" content="http://example.com/movie.swf" />
<meta property="og:video:secure_url" content="https://secure.example.com/movie.swf" />
<meta property="og:video:type" content="application/x-shockwave-flash" />
<meta property="og:video:width" content="400" />
<meta property="og:video:height" content="300" />The og:audio tag only has the first 3 properties available (since size doesn't make sense for sound):
<meta property="og:audio" content="http://example.com/sound.mp3" />
<meta property="og:audio:secure_url" content="https://secure.example.com/sound.mp3" />
<meta property="og:audio:type" content="audio/mpeg" />Arrays If a tag can have multiple values, just put multiple versions of the same tag on your page. The first tag (from top to bottom) is given preference during conflicts.
<meta property="og:image" content="http://example.com/rock.jpg" />
<meta property="og:image" content="http://example.com/rock2.jpg" />Put structured properties after you declare their root tag. Whenever another root element is parsed, that structured property is considered to be done and another one is started.
For example:
<meta property="og:image" content="http://example.com/rock.jpg" />
<meta property="og:image:width" content="300" />
<meta property="og:image:height" content="300" />
<meta property="og:image" content="http://example.com/rock2.jpg" />
<meta property="og:image" content="http://example.com/rock3.jpg" />
<meta property="og:image:height" content="1000" />means there are 3 images on this page, the first image is 300x300, the middle one has unspecified dimensions, and the last one is 1000px tall.
Object Types In order for your object to be represented within the graph, you need to specify its type. This is done using the og:type property:
<meta property="og:type" content="website" />When the community agrees on the schema for a type, it is added to the list of global types. All other objects in the type system are CURIEs of the form
<head prefix="my_namespace: http://example.com/ns#">
<meta property="og:type" content="my_namespace:my_type" />The global types are grouped into verticals. Each vertical has its own namespace. The og:type values for a namespace are always prefixed with the namespace and then a period. This is to reduce confusion with user-defined namespaced types which always have colons in them.
Music Namespace URI: http://ogp.me/ns/music# og:type values: