Remove Class Filters w/ Wordpress ID/Hash Conditional

remove_class_filters.php

/**
 * Make sure the function does not exist before defining it
 */
if( ! function_exists( 'remove_class_filter' ) ){

  /**
   * Remove Class Filter Without Access to Class Object
   *
   * In order to use the core WordPress remove_filter() on a filter added with the callback
   * to a class, you either have to have access to that class object, or it has to be a call
   * to a static method.  This method allows you to remove filters with a callback to a class
   * you don't have access to.
   *
   * Works with WordPress 1.2+ (4.7+ support added 9-19-2016)
   * Updated 2-27-2017 to use internal WordPress removal for 4.7+ (to prevent PHP warnings output)
   * Updated 03-04-2022 to account for wordpress id/hashes that are often prepended to filters.
   *
   * @param string $tag         Filter to remove
   * @param string $class_name  Class name for the filter's callback
   * @param string $method_name Method name for the filter's callback
   * @param int    $priority    Priority of the filter (default 10)
   *
   * @return bool Whether the function is removed.
   */
  
  function remove_class_filter( $tag, $class_name = '', $method_name = '', $priority = 10 ) {
    global $wp_filter;
  
    // Setting up variables in the event that Wordpress prepends a hash to the method
    $method_key = $GLOBALS['wp_filter'][$tag]->callbacks[$priority];
    $method_keyname = implode( preg_grep( '/' . preg_quote($method_name) . '/', array_keys($method_key) ) );
    $method_hash = substr( $method_keyname, 0, -strlen($method_name) );
  
    // Check that filter actually exists first
    if ( ! isset( $wp_filter[ $tag ] ) ) {
      return FALSE;
    }

    /**
     * If filter config is an object, means we're using WordPress 4.7+ and the config is no longer
     * a simple array, rather it is an object that implements the ArrayAccess interface.
     *
     * To be backwards compatible, we set $callbacks equal to the correct array as a reference (so $wp_filter is updated)
     *
     * @see https://make.wordpress.org/core/2016/09/08/wp_hook-next-generation-actions-and-filters/
     */
    if ( is_object( $wp_filter[ $tag ] ) && isset( $wp_filter[ $tag ]->callbacks ) ) {
      // Create $fob object from filter tag, to use below
      $fob       = $wp_filter[ $tag ];
      $callbacks = &$wp_filter[ $tag ]->callbacks;
    } else {
      $callbacks = &$wp_filter[ $tag ];
    }

    // Exit if there aren't any callbacks for specified priority
    if ( ! isset( $callbacks[ $priority ] ) || empty( $callbacks[ $priority ] ) ) {
      return FALSE;
    }

    // Loop through each filter for the specified priority, looking for our class & method
    foreach ( (array) $callbacks[ $priority ] as $filter_id => $filter ) {

      // Filter should always be an array - array( $this, 'method' ), if not goto next
      if ( ! isset( $filter['function'] ) || ! is_array( $filter['function'] ) ) {
        continue;
      }

      // If first value in array is not an object, it can't be a class
      if ( ! is_object( $filter['function'][0] ) ) {
        continue;
      }

      // Method doesn't match the one we're looking for, goto next
      if ( $filter['function'][1] !== $method_name ) {
        continue;
      }

      // Method doesn't match with WP unique ID / Hash appended
      if ( $method_hash . $filter['function'][1] !== $method_keyname ) {
        continue;
      }
      
      // Method matched, now let's check the Class
      if ( get_class( $filter['function'][0] ) === $class_name ) {
        
        
        // WordPress 4.7+ use core remove_filter() since we found the class object
        if ( isset( $fob ) ) {

          // Handles removing filter, reseting callback priority keys mid-iteration, etc.
          $fob->remove_filter( $tag, $filter['function'], $priority );

        } else {
          // Use legacy removal process (pre 4.7)
          unset( $callbacks[ $priority ][ $filter_id ] );
          // and if it was the only filter in that priority, unset that priority
          if ( empty( $callbacks[ $priority ] ) ) {
            unset( $callbacks[ $priority ] );
          }
          // and if the only filter for that tag, set the tag to an empty array
          if ( empty( $callbacks ) ) {
            $callbacks = array();
          }
          // Remove this filter from merged_filters, which specifies if filters have been sorted
          unset( $GLOBALS['merged_filters'][ $tag ] );
        }

        return TRUE;
      }
    }
    
    return FALSE;
  }
}

/**
 * Make sure the function does not exist before defining it
 */
if( ! function_exists( 'remove_class_action') ){

  /**
   * Remove Class Action Without Access to Class Object
   *
   * In order to use the core WordPress remove_action() on an action added with the callback
   * to a class, you either have to have access to that class object, or it has to be a call
   * to a static method.  This method allows you to remove actions with a callback to a class
   * you don't have access to.
   *
   * Works with WordPress 1.2+ (4.7+ support added 9-19-2016)
   *
   * @param string $tag         Action to remove
   * @param string $class_name  Class name for the action's callback
   * @param string $method_name Method name for the action's callback
   * @param int    $priority    Priority of the action (default 10)
   *
   * @return bool               Whether the function is removed.
   */
  function remove_class_action( $tag, $class_name = '', $method_name = '', $priority = 10 ) {
    remove_class_filter( $tag, $class_name, $method_name, $priority );
  }
}


/*

// APPLICATION EXAMPLE (place this in a functions.php file or have it referenced
// This specific example is to remove these polylang filters which were really slowing down page speed (redis)
// NOTE: the priority stated in remove_class_filter must match the original filter defined in the plugin
// NOTE2: The supplementary remove_filter was necessary to completely shed caching for polylang terms and it needed to happen in this order to work (hence numbered comments)

// Polylang Terms Caching (disabled)
// 1. Removes filters registered in the Polylang Plugin (priority must be exact match)
add_action('init', function(){
  remove_class_filter( 'get_terms', 'PLL_Translated_Term', '_prime_terms_cache', 10);
  remove_class_filter( 'get_object_terms', 'PLL_Translated_Term', 'wp_get_object_terms', 10);
  remove_class_action( 'clean_term_cache', 'PLL_Translated_Term', 'clean_term_cache', 10 );
}, 99);

// 2. Supplementary to remove_class_action by targeting parent classes too.
add_action('init', function(){
	remove_filter('get_terms', ['PLL_Translated_Term', '_prime_terms_cache'], 10);
	remove_filter('get_object_terms', ['PLL_Translated_Term', 'wp_get_object_terms'], 10);
	remove_action('clean_term_cache', ['PLL_Translated_Term', 'clean_term_cache'], 10);
}, 99);
*/