oembed-in-comments.php

<?php

/**
 * Plugin Name: oEmbed in Comments
 * Description: Allow oEmbeds in comment text. A fork of http://wordpress.org/plugins/oembed-in-comments/
 * Version: 1.2
 * Author: Evan Solomon, modified by Shea Bunge
 */

class oEmbed_Comments {

  static function init() {
		if ( is_admin() )
			return;

		$this->add_filter();
	}

	/**
	 * Setup filter with correct priority to do oEmbed in comments
   * 
   * @since 1.0
   * @uses add_filter To register a filter hook
   * @uses has_filter() To check if a filter is registered
	 */
	function add_filter() {
    
		/* make_clickable breaks oEmbed regex, make sure we go earlier */
		$clickable = has_filter( 'comment_text', 'make_clickable' );
		$priority = ( $clickable ) ? $clickable - 1 : 10;

		add_filter( 'comment_text', array( $this, 'oembed_filter' ), $priority );
	}

	/**
	 * Safely add oEmbed media to a comment
	 */
	function oembed_filter( $comment_text ) {
		global $wp_embed;

		// Automatic discovery would be a security risk, safety first
		add_filter( 'embed_oembed_discover', '__return_false', 999 );
		$comment_text = $wp_embed->autoembed( $comment_text );

		// ...but don't break your posts if you use it
		remove_filter( 'embed_oembed_discover', '__return_false', 999 );

		return $comment_text;
	}
}

add_action( 'init', array( 'oEmbed_Comments', 'init' ) );