remove_action( string $hook_name, callable|string|array $callback, int $priority = 10 )

使用示例

• 示例1

  此函数与remove_filter()函数相同。

  <?php remove_action( $tag, $function_to_remove, $priority ); ?> 
  

  remove_action()必须在函数内部调用，不能在插件或主题中直接调用。

  <?php
  add_action( 'wp_head', 'remove_my_action' );
  function remove_my_action() {
  	remove_action( 'wp_footer', 'function_being_removed' );
  }
  ?>
  

  如果一个动作是从一个类中添加的，例如通过一个插件添加的，那么移除它将需要通过一个保存该类实例的变量访问该类。

  add_action( 'wp_head', 'remove_my_class_action' );
  function remove_my_class_action() {
  	global $my_class;
  	remove_action( 'wp_footer', array( $my_class, 'class_function_being_removed' ) );
  }
  

  除非函数是静态的，在这种情况下可以直接调用类和函数。

  add_action( 'wp_head', 'remove_my_class_action' );
  function remove_my_class_action() {
  	remove_action( 'wp_footer', array( 'My_Class', 'class_function_being_removed' ) );
  }
  

  笔记：

  1. 您可能需要把移除动作的工作优先安排在动作添加后发生的钩子上。
  2. 在添加动作之前，无法成功删除该动作。
  3. 您也不能在动作运行后删除它。
  4. 要删除动作，优先级必须与最初添加的函数的优先级匹配。
• 示例2

  如果您需要能够删除您无权访问的类对象的动作/过滤器，可以使用此函数（包括对WordPress 4.7+的支持）：

  /**
   * 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)
  	 *
  	 * @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;
  		// 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 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 );
  	}
  }

• 示例3

  相关：

  do_action()
  add_action()

• 示例4

  /**
  * Different way to remove hooks declare inside class
  */
  
  class MyClass {
  	
  	/**
  	 * The single instance of the class.
  	 * 
  	 */
  	protected static $_instance = null;
  
  	/**
  	 * Main plugins instance
  	 *
  	 * Ensures only one instance of this class
  	 * Its always good practice to user single instance of the class so we can modify hooks initialized on this class
  	 */
  	public static function get_instance() {
  		if ( is_null( self::$_instance ) ) {
  			self::$_instance = new self();
  		}
  		return self::$_instance;
  	}
  
  	/**
  	* Register hoooks
  	*/
  	public function __construct() {
  		/*
  		* @hooked add_custom_body_class 10
  		*/
  		add_filter( 'body_class', array( $this, 'add_custom_body_class' ) );
  		/*
  		* @hooked static static_body_class - 20
  		*/
  		add_filter( 'body_class', array( 'MyClass', 'static_body_class' ),  20 );
  	}
  	/**
  	* @return array of class
  	*/
  	public function add_custom_body_class( $class ) {
  		$class[ 'custom_class' ] = 'customClass';
  		return $class;
  	}
  	/**
  	* @return array of class
  	*/
  	static function static_body_class( $class ) {
  		$class[ 'static_custom_class' ] = 'staticCustomClass';
  		return $class;
  	}
  }
  $my_class = MyClass::get_instance();
  
  /**
  * Remove methods: add_custom_body_class attached to body class
  */
  add_action( 'wp_head', 'themeslug_remove_hooks' );
  function themeslug_remove_hooks() {
  	/**
  	* Always use same class object, this can be achieve by restricting multiple instance of the class
  	*/
  	$is_action_removed = remove_action( 'body_class', array( MyClass::get_instance(), 'add_custom_body_class'  ) );
  	/**
  	* Remove static method class by using class name with same priority 20
  	*/
  	$is_action_removed = remove_action( 'body_class', array( 'MyClass', 'static_body_class'  ), 20 );
  }