wp_rel_nofollow_callback

Callback to add rel=nofollow string to HTML A element.

Description

(string) wp_rel_nofollow_callback( (array) $matches ); 

Will remove already existing rel="nofollow" and rel='nofollow' from the string to prevent from invalidating (X)HTML.

Returns (string)

HTML A Element with rel nofollow.

Parameters (1)

0. $matches (array)
The matches.

Usage

  1. if ( !function_exists( 'wp_rel_nofollow_callback' ) ) { 
  2.     require_once ABSPATH . WPINC . '/formatting.php'; 
  3. } 
  4.   
  5. // The matches. 
  6. $matches = array(); 
  7.   
  8. // NOTICE! Understand what this does before running. 
  9. $result = wp_rel_nofollow_callback($matches); 
  10.     

Defined (1)

The function is defined in the following location(s).

/wp-includes/formatting.php  
  1. function wp_rel_nofollow_callback( $matches ) { 
  2.     $text = $matches[1]; 
  3.     $atts = shortcode_parse_atts( $matches[1] ); 
  4.     $rel = 'nofollow'; 
  5.  
  6.     if ( preg_match( '%href=["\'](' . preg_quote( set_url_scheme( home_url(), 'http' ) ) . ')%i', $text ) || 
  7.          preg_match( '%href=["\'](' . preg_quote( set_url_scheme( home_url(), 'https' ) ) . ')%i', $text ) 
  8.  ) { 
  9.         return "<a $text>"; 
  10.     } 
  11.  
  12.     if ( ! empty( $atts['rel'] ) ) { 
  13.         $parts = array_map( 'trim', explode( ' ', $atts['rel'] ) ); 
  14.         if ( false === array_search( 'nofollow', $parts ) ) { 
  15.             $parts[] = 'nofollow'; 
  16.         } 
  17.         $rel = implode( ' ', $parts ); 
  18.         unset( $atts['rel'] ); 
  19.  
  20.         $html = ''; 
  21.         foreach ( $atts as $name => $value ) { 
  22.             $html .= "{$name}=\"$value\" "; 
  23.         } 
  24.         $text = trim( $html ); 
  25.     } 
  26.     return "<a $text rel=\"$rel\">"; 
  27. }