Autoembeds don’t work with paragraphs

by

The reason why this is happening, seems to be found in the file wp-includes/class-wp-embed.php in the autoembed call-back method: 

/**
 * Passes any unlinked URLs that are on their own line to {@link WP_Embed::shortcode()} for potential embedding.
 *
 * @uses WP_Embed::autoembed_callback()
 *
 * @param string $content The content to be searched.
 * @return string Potentially modified $content.
 */
function autoembed( $content ) {
    return preg_replace_callback( '|^\s*(https?://[^\s"]+)\s*$|im', array( $this, 'autoembed_callback' ), $content );
}

where 

// Attempts to embed all URLs in a post
add_filter( 'the_content', array( $this, 'autoembed' ), 8 );

As I understand it, the matching lines have to contain only a link, which could be wrapped by any number of whitespace characters before and after the link itself.

So this pattern would exclude this line:

<p>http://www.youtube.com/watch?v=xxxxxxxxxxx</p>

You could try to add your own the_content filter that adds a new line before and after your links inside the paragraph tags around your link. This should be done before the autoembed filter is executed, so it should have priority under 8.

Filter Example:

One can play with the regular expressions in this great online tool:

http://regexr.com?36eat

where I’ve inserted the pattern:

^<p>\s*(https?://[^\s"]+)\s*</p>$

with the replacement:

<p>\n$1\n</p>

You can adjust this to your needs.

Here is one idea for such a custom filter:

add_filter( 'the_content', 'my_autoembed_adjustments', 7 );

/**
 * Add a new line around paragraph links
 * @param string $content
 * @return string $content
 */
function my_autoembed_adjustments( $content ){

    $pattern = '|<p>\s*(https?://[^\s"]+)\s*</p>|im';    // your own pattern
    $to      = "<p>\n$1\n</p>";                          // your own pattern
    $content = preg_replace( $pattern, $to, $content );

    return $content;

}

Leave a Comment