WordPress.com and Jetpack are built on top of the open-source WordPress.org publishing platform. Third-party embed providers must have significant market interest before being considered for inclusion on WordPress.com. We also highly encourage having a fully functional WordPress.org plugin.
Our preferred method for supporting third-party embeds is the oEmbed standard. Supporting oEmbed increases the likelihood of an easy integration with WordPress.com and Jetpack.
WordPress Shortcode API
WordPress Shortcodes translate complex embed codes into simple macros. The WordPress publishing system, with the help of your custom plugin, converts shortcodes into the best possible markup for the requesting agent. Shortcodes help embedded content expand to the full content width of a blog theme, display different content to mobile and desktop browsers, or add specific content to web feeds. Shortcodes are the preferred embed method for WordPress sites including WordPress.com.
[mysite id="abc123" fmt=22]
WordPress passes key-value attribute pairs to a shortcode plugin registered for a given shortcode name. In the example above the shortcode “mysite” receives an
array with an unique identifier and format code specific to a fictional “mysite” service. The shortcode handler should recognize and verify embed customizations unique to your service. Take a look at your existing generic embed markup and define all customizations you would like a post author to configure on his or her WordPress blog.
Many WordPress themes store the width of the theme’s main content column in the
content_width global variable. Shortcode handlers should be aware of the blog’s current theme and the full width available to embedded content. Post authors may want to override this default handling inside the shortcode or define the desired width of your embedded content by defining a width or height attribute (commonly abbreviated “w” and “h” in shortcode markup).
Filtering post embed content
Embed markup copy and pasted from other websites passes through WordPress HTML filters before being saved into the WordPress database. Plugins connected to the
pre_kses filter can scan post content for markup better served by a WordPress Shortcode and replace the appropriate text with equivalent shortcode attributes.
Plugins should recognize customization parameters present in embed markup before converting to a shortcode. If a publisher customized an embed on your website before inserting into his or her post you should preserve such preferences inside a shortcode where supported.
Additional development notes
Plugins requesting remote resources over HTTP should use the WordPress HTTP API for maximum compatibility across WordPress installations and related plugins.
Self-hosted WordPress requires PHP 5.2.4 or greater. WordPress.com runs the latest version of PHP (last update: PHP 5.5 February 2014).
WordPress.org hosts and distributes plugins licensed under a GPLv2-compatible license. Plugins approved for distribution through WordPress.org receive access to a subversion repository, distribution through the WordPress.org website, installation and upgrade support through the WordPress administrative interface and plugin usage statistics.
Automattic evaluates the popularity and reported issues with existing embed plugins before considering such plugins for inclusion in WordPress.com and Jetpack.