get_shortcode_regex( array $tagnames = null )

Retrieve the shortcode regular expression for searching.


Description Description

The regular expression combines the shortcode tags in the regular expression in a regex class.

The regular expression contains 6 different sub matches to help with parsing.

1 – An extra [ to allow for escaping shortcodes with double [[]] 2 – The shortcode name 3 – The shortcode argument list 4 – The self closing / 5 – The content of a shortcode when it wraps some content. 6 – An extra ] to allow for escaping shortcodes with double [[]]


Parameters Parameters

$tagnames

(array) (Optional) List of shortcodes to find. Defaults to all registered shortcodes.

Default value: null


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Return Return

(string) The shortcode search regular expression


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Source Source

File: wp-includes/shortcodes.php

function get_shortcode_regex( $tagnames = null ) {
	global $shortcode_tags;

	if ( empty( $tagnames ) ) {
		$tagnames = array_keys( $shortcode_tags );
	}
	$tagregexp = join( '|', array_map('preg_quote', $tagnames) );

	// WARNING! Do not change this regex without changing do_shortcode_tag() and strip_shortcode_tag()
	// Also, see shortcode_unautop() and shortcode.js.
	return
		  '\\['                              // Opening bracket
		. '(\\[?)'                           // 1: Optional second opening bracket for escaping shortcodes: [[tag]]
		. "($tagregexp)"                     // 2: Shortcode name
		. '(?![\\w-])'                       // Not followed by word character or hyphen
		. '('                                // 3: Unroll the loop: Inside the opening shortcode tag
		.     '[^\\]\\/]*'                   // Not a closing bracket or forward slash
		.     '(?:'
		.         '\\/(?!\\])'               // A forward slash not followed by a closing bracket
		.         '[^\\]\\/]*'               // Not a closing bracket or forward slash
		.     ')*?'
		. ')'
		. '(?:'
		.     '(\\/)'                        // 4: Self closing tag ...
		.     '\\]'                          // ... and closing bracket
		. '|'
		.     '\\]'                          // Closing bracket
		.     '(?:'
		.         '('                        // 5: Unroll the loop: Optionally, anything between the opening and closing shortcode tags
		.             '[^\\[]*+'             // Not an opening bracket
		.             '(?:'
		.                 '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
		.                 '[^\\[]*+'         // Not an opening bracket
		.             ')*+'
		.         ')'
		.         '\\[\\/\\2\\]'             // Closing shortcode tag
		.     ')?'
		. ')'
		. '(\\]?)';                          // 6: Optional second closing brocket for escaping shortcodes: [[tag]]
}

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Changelog Changelog

Changelog
Version Description
4.4.0 Added the $tagnames parameter.
2.5.0 Introduced.


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User Contributed Notes User Contributed Notes

  1. Skip to note content
    Contributed by Codex

    Example

    /**
     * Detect shortcodes in the global $post.
     */
    function wpdocs_detect_shortcode() {
    	global $post;
    	$pattern = get_shortcode_regex();
    
    	if (   preg_match_all( '/'. $pattern .'/s', $post->post_content, $matches )
    		&& array_key_exists( 2, $matches )
    		&& in_array( 'your-shortcode', $matches[2] )
    	) {
    		// shortcode is being used
    	}
    }
    add_action( 'wp', 'wpdocs_detect_shortcode' );
    

    This can only be used when $post is available. ‘wp’ is the earliest action you can hook into to get access to it.

    The following code is an adjustment of the first example, but able to also search all posts on the index page.

    /**
     * Detect shortcodes in the global $post.
     */
    function wpdocs_detect_shortcode() {
    	global $wp_query;	
    	$posts = $wp_query->posts;
    	$pattern = get_shortcode_regex();
        
    	foreach ( $posts as $post ) {
    		if ( preg_match_all( '/'. $pattern .'/s', $post->post_content, $matches )
    			&& array_key_exists( 2, $matches )
    			&& in_array( 'videoannotation', $matches[2] )
    		) {
    			// enque my css and js
    			break;	
    		}    
    	}
    }
    add_action( 'wp', 'wpdocs_detect_shortcode' );
    

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