Opengraph support

[johanjanssens]

Opengraph support

This PR implements automatic support for opengraph and additionally twitter cards. For an overview of both standards please see:

• http://ogp.me/#metadata
• https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/markup

1. Default properties

• og:type; defaults to website
• og:image; defaults to page image
• og:title; defaults to page title
• og:description; defaults to page description
• og:url, defaults to the page url

For opengraph metadata to be added to the page both the og:type and og:image properties need to be defined.

2. Custom properties

Properties can be added or custom values for defaults defined by specifying them in the page frontmatter. Example:

metadata:
   'og:type': article  
   'og:author': john doe

3. Global properties

Default properties can be configured, or additional properties can be added using a new 'metadata' config option. Example:

return array(
   'metadata' => [
        'og:site_name' => 'Joomlatools',
        'og:image'     => '/images/default_card.jpg',
        'twitter:site' => '@joomlatools',
        'twitter:card' => 'summary_large_image',
     ]
);

4. Disabling opengraph

Opengraph support can be disabled by setting the 'og:type' metadata property to false.

return array(
   'metadata' => [
        'og:type'  => false
     ]
);

Notes

• The image should be a site absolute image path, or a url. If it's a path it's transformed into a url when the metadata is being rendered.

• For twitter we making use of the opengraph properties supported by twitter. For info see: https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/markup Specific twitter properties need to be defined either in the page frontmatter of in the global configuration.

Additional improvements

This PR also adds a page ìmage`property.

[ercanozkaya]

@johanjanssens left an inline comment