X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/wordpress.git/blobdiff_plain/8d3bb1a5dcfdea9857d3c88c3751f09593e34dc8..ef91a7f4f3c6468973e192335a27ec0e0faca0b5:/wp-includes/class-wp-hook.php

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+<?php
+/**
+ * Plugin API: WP_Hook class
+ *
+ * @package WordPress
+ * @subpackage Plugin
+ * @since 4.7.0
+ */
+
+/**
+ * Core class used to implement action and filter hook functionality.
+ *
+ * @since 4.7.0
+ *
+ * @see Iterator
+ * @see ArrayAccess
+ */
+final class WP_Hook implements Iterator, ArrayAccess {
+
+	/**
+	 * Hook callbacks.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 * @var array
+	 */
+	public $callbacks = array();
+
+	/**
+	 * The priority keys of actively running iterations of a hook.
+	 *
+	 * @since 4.7.0
+	 * @access private
+	 * @var array
+	 */
+	private $iterations = array();
+
+	/**
+	 * The current priority of actively running iterations of a hook.
+	 *
+	 * @since 4.7.0
+	 * @access private
+	 * @var array
+	 */
+	private $current_priority = array();
+
+	/**
+	 * Number of levels this hook can be recursively called.
+	 *
+	 * @since 4.7.0
+	 * @access private
+	 * @var int
+	 */
+	private $nesting_level = 0;
+
+	/**
+	 * Flag for if we're current doing an action, rather than a filter.
+	 *
+	 * @since 4.7.0
+	 * @access private
+	 * @var bool
+	 */
+	private $doing_action = false;
+
+	/**
+	 * Hooks a function or method to a specific filter action.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param string   $tag             The name of the filter to hook the $function_to_add callback to.
+	 * @param callable $function_to_add The callback to be run when the filter is applied.
+	 * @param int      $priority        The order in which the functions associated with a
+	 *                                  particular action are executed. Lower numbers correspond with
+	 *                                  earlier execution, and functions with the same priority are executed
+	 *                                  in the order in which they were added to the action.
+	 * @param int      $accepted_args   The number of arguments the function accepts.
+	 */
+	public function add_filter( $tag, $function_to_add, $priority, $accepted_args ) {
+		$idx = _wp_filter_build_unique_id( $tag, $function_to_add, $priority );
+		$priority_existed = isset( $this->callbacks[ $priority ] );
+
+		$this->callbacks[ $priority ][ $idx ] = array(
+			'function' => $function_to_add,
+			'accepted_args' => $accepted_args
+		);
+
+		// if we're adding a new priority to the list, put them back in sorted order
+		if ( ! $priority_existed && count( $this->callbacks ) > 1 ) {
+			ksort( $this->callbacks, SORT_NUMERIC );
+		}
+
+		if ( $this->nesting_level > 0 ) {
+			$this->resort_active_iterations( $priority, $priority_existed );
+		}
+	}
+
+	/**
+	 * Handles reseting callback priority keys mid-iteration.
+	 *
+	 * @since 4.7.0
+	 * @access private
+	 *
+	 * @param bool|int $new_priority     Optional. The priority of the new filter being added. Default false,
+	 *                                   for no priority being added.
+	 * @param bool     $priority_existed Optional. Flag for whether the priority already existed before the new
+	 *                                   filter was added. Default false.
+	 */
+	private function resort_active_iterations( $new_priority = false, $priority_existed = false ) {
+		$new_priorities = array_keys( $this->callbacks );
+
+		// If there are no remaining hooks, clear out all running iterations.
+		if ( ! $new_priorities ) {
+			foreach ( $this->iterations as $index => $iteration ) {
+				$this->iterations[ $index ] = $new_priorities;
+			}
+			return;
+		}
+
+		$min = min( $new_priorities );
+		foreach ( $this->iterations as $index => &$iteration ) {
+			$current = current( $iteration );
+			// If we're already at the end of this iteration, just leave the array pointer where it is.
+			if ( false === $current ) {
+				continue;
+			}
+
+			$iteration = $new_priorities;
+
+			if ( $current < $min ) {
+				array_unshift( $iteration, $current );
+				continue;
+			}
+
+			while ( current( $iteration ) < $current ) {
+				if ( false === next( $iteration ) ) {
+					break;
+				}
+			}
+
+			// If we have a new priority that didn't exist, but ::apply_filters() or ::do_action() thinks it's the current priority...
+			if ( $new_priority === $this->current_priority[ $index ] && ! $priority_existed ) {
+				/*
+				 * ... and the new priority is the same as what $this->iterations thinks is the previous
+				 * priority, we need to move back to it.
+				 */
+
+				if ( false === current( $iteration ) ) {
+					// If we've already moved off the end of the array, go back to the last element.
+					$prev = end( $iteration );
+				} else {
+					// Otherwise, just go back to the previous element.
+					$prev = prev( $iteration );
+				}
+				if ( false === $prev ) {
+					// Start of the array. Reset, and go about our day.
+					reset( $iteration );
+				} elseif ( $new_priority !== $prev ) {
+					// Previous wasn't the same. Move forward again.
+					next( $iteration );
+				}
+			}
+		}
+		unset( $iteration );
+	}
+
+	/**
+	 * Unhooks a function or method from a specific filter action.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param string   $tag                The filter hook to which the function to be removed is hooked. Used
+	 *                                     for building the callback ID when SPL is not available.
+	 * @param callable $function_to_remove The callback to be removed from running when the filter is applied.
+	 * @param int      $priority           The exact priority used when adding the original filter callback.
+	 * @return bool Whether the callback existed before it was removed.
+	 */
+	public function remove_filter( $tag, $function_to_remove, $priority ) {
+		$function_key = _wp_filter_build_unique_id( $tag, $function_to_remove, $priority );
+
+		$exists = isset( $this->callbacks[ $priority ][ $function_key ] );
+		if ( $exists ) {
+			unset( $this->callbacks[ $priority ][ $function_key ] );
+			if ( ! $this->callbacks[ $priority ] ) {
+				unset( $this->callbacks[ $priority ] );
+				if ( $this->nesting_level > 0 ) {
+					$this->resort_active_iterations();
+				}
+			}
+		}
+		return $exists;
+	}
+
+	/**
+	 * Checks if a specific action has been registered for this hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param callable|bool $function_to_check Optional. The callback to check for. Default false.
+	 * @param string        $tag               Optional. The name of the filter hook. Used for building
+	 *                                         the callback ID when SPL is not available. Default empty.
+	 * @return bool|int The priority of that hook is returned, or false if the function is not attached.
+	 */
+	public function has_filter( $tag = '', $function_to_check = false ) {
+		if ( false === $function_to_check ) {
+			return $this->has_filters();
+		}
+
+		$function_key = _wp_filter_build_unique_id( $tag, $function_to_check, false );
+		if ( ! $function_key ) {
+			return false;
+		}
+
+		foreach ( $this->callbacks as $priority => $callbacks ) {
+			if ( isset( $callbacks[ $function_key ] ) ) {
+				return $priority;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Checks if any callbacks have been registered for this hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @return bool True if callbacks have been registered for the current hook, otherwise false.
+	 */
+	public function has_filters() {
+		foreach ( $this->callbacks as $callbacks ) {
+			if ( $callbacks ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Removes all callbacks from the current filter.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param int|bool $priority Optional. The priority number to remove. Default false.
+	 */
+	public function remove_all_filters( $priority = false ) {
+		if ( ! $this->callbacks ) {
+			return;
+		}
+
+		if ( false === $priority ) {
+			$this->callbacks = array();
+		} else if ( isset( $this->callbacks[ $priority ] ) ) {
+			unset( $this->callbacks[ $priority ] );
+		}
+
+		if ( $this->nesting_level > 0 ) {
+			$this->resort_active_iterations();
+		}
+	}
+
+	/**
+	 * Calls the callback functions added to a filter hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param mixed $value The value to filter.
+	 * @param array $args  Arguments to pass to callbacks.
+	 * @return mixed The filtered value after all hooked functions are applied to it.
+	 */
+	public function apply_filters( $value, $args ) {
+		if ( ! $this->callbacks ) {
+			return $value;
+		}
+
+		$nesting_level = $this->nesting_level++;
+
+		$this->iterations[ $nesting_level ] = array_keys( $this->callbacks );
+		$num_args = count( $args );
+
+		do {
+			$this->current_priority[ $nesting_level ] = $priority = current( $this->iterations[ $nesting_level ] );
+
+			foreach ( $this->callbacks[ $priority ] as $the_ ) {
+				if( ! $this->doing_action ) {
+					$args[ 0 ] = $value;
+				}
+
+				// Avoid the array_slice if possible.
+				if ( $the_['accepted_args'] == 0 ) {
+					$value = call_user_func_array( $the_['function'], array() );
+				} elseif ( $the_['accepted_args'] >= $num_args ) {
+					$value = call_user_func_array( $the_['function'], $args );
+				} else {
+					$value = call_user_func_array( $the_['function'], array_slice( $args, 0, (int)$the_['accepted_args'] ) );
+				}
+			}
+		} while ( false !== next( $this->iterations[ $nesting_level ] ) );
+
+		unset( $this->iterations[ $nesting_level ] );
+		unset( $this->current_priority[ $nesting_level ] );
+
+		$this->nesting_level--;
+
+		return $value;
+	}
+
+	/**
+	 * Executes the callback functions hooked on a specific action hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param mixed $args Arguments to pass to the hook callbacks.
+	 */
+	public function do_action( $args ) {
+		$this->doing_action = true;
+		$this->apply_filters( '', $args );
+
+		// If there are recursive calls to the current action, we haven't finished it until we get to the last one.
+		if ( ! $this->nesting_level ) {
+			$this->doing_action = false;
+		}
+	}
+
+	/**
+	 * Processes the functions hooked into the 'all' hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @param array $args Arguments to pass to the hook callbacks. Passed by reference.
+	 */
+	public function do_all_hook( &$args ) {
+		$nesting_level = $this->nesting_level++;
+		$this->iterations[ $nesting_level ] = array_keys( $this->callbacks );
+
+		do {
+			$priority = current( $this->iterations[ $nesting_level ] );
+			foreach ( $this->callbacks[ $priority ] as $the_ ) {
+				call_user_func_array( $the_['function'], $args );
+			}
+		} while ( false !== next( $this->iterations[ $nesting_level ] ) );
+
+		unset( $this->iterations[ $nesting_level ] );
+		$this->nesting_level--;
+	}
+
+	/**
+	 * Return the current priority level of the currently running iteration of the hook.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @return int|false If the hook is running, return the current priority level. If it isn't running, return false.
+	 */
+	public function current_priority() {
+		if ( false === current( $this->iterations ) ) {
+			return false;
+		}
+
+		return current( current( $this->iterations ) );
+	}
+
+	/**
+	 * Normalizes filters set up before WordPress has initialized to WP_Hook objects.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 * @static
+	 *
+	 * @param array $filters Filters to normalize.
+	 * @return WP_Hook[] Array of normalized filters.
+	 */
+	public static function build_preinitialized_hooks( $filters ) {
+		/** @var WP_Hook[] $normalized */
+		$normalized = array();
+
+		foreach ( $filters as $tag => $callback_groups ) {
+			if ( is_object( $callback_groups ) && $callback_groups instanceof WP_Hook ) {
+				$normalized[ $tag ] = $callback_groups;
+				continue;
+			}
+			$hook = new WP_Hook();
+
+			// Loop through callback groups.
+			foreach ( $callback_groups as $priority => $callbacks ) {
+
+				// Loop through callbacks.
+				foreach ( $callbacks as $cb ) {
+					$hook->add_filter( $tag, $cb['function'], $priority, $cb['accepted_args'] );
+				}
+			}
+			$normalized[ $tag ] = $hook;
+		}
+		return $normalized;
+	}
+
+	/**
+	 * Determines whether an offset value exists.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/arrayaccess.offsetexists.php
+	 *
+	 * @param mixed $offset An offset to check for.
+	 * @return bool True if the offset exists, false otherwise.
+	 */
+	public function offsetExists( $offset ) {
+		return isset( $this->callbacks[ $offset ] );
+	}
+
+	/**
+	 * Retrieves a value at a specified offset.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/arrayaccess.offsetget.php
+	 *
+	 * @param mixed $offset The offset to retrieve.
+	 * @return mixed If set, the value at the specified offset, null otherwise.
+	 */
+	public function offsetGet( $offset ) {
+		return isset( $this->callbacks[ $offset ] ) ? $this->callbacks[ $offset ] : null;
+	}
+
+	/**
+	 * Sets a value at a specified offset.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/arrayaccess.offsetset.php
+	 *
+	 * @param mixed $offset The offset to assign the value to.
+	 * @param mixed $value The value to set.
+	 */
+	public function offsetSet( $offset, $value ) {
+		if ( is_null( $offset ) ) {
+			$this->callbacks[] = $value;
+		} else {
+			$this->callbacks[ $offset ] = $value;
+		}
+	}
+
+	/**
+	 * Unsets a specified offset.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/arrayaccess.offsetunset.php
+	 *
+	 * @param mixed $offset The offset to unset.
+	 */
+	public function offsetUnset( $offset ) {
+		unset( $this->callbacks[ $offset ] );
+	}
+
+	/**
+	 * Returns the current element.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/iterator.current.php
+	 *
+	 * @return array Of callbacks at current priority.
+	 */
+	public function current() {
+		return current( $this->callbacks );
+	}
+
+	/**
+	 * Moves forward to the next element.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/iterator.next.php
+	 *
+	 * @return array Of callbacks at next priority.
+	 */
+	public function next() {
+		return next( $this->callbacks );
+	}
+
+	/**
+	 * Returns the key of the current element.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/iterator.key.php
+	 *
+	 * @return mixed Returns current priority on success, or NULL on failure
+	 */
+	public function key() {
+		return key( $this->callbacks );
+	}
+
+	/**
+	 * Checks if current position is valid.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/iterator.valid.php
+	 *
+	 * @return boolean
+	 */
+	public function valid() {
+		return key( $this->callbacks ) !== null;
+	}
+
+	/**
+	 * Rewinds the Iterator to the first element.
+	 *
+	 * @since 4.7.0
+	 * @access public
+	 *
+	 * @link http://php.net/manual/en/iterator.rewind.php
+	 */
+	public function rewind() {
+		reset( $this->callbacks );
+	}
+
+}