File Content: class-wp-hook.php <?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 * @var array */ public $callbacks = array(); /** * The priority keys of actively running iterations of a hook. * * @since 4.7.0 * @var array */ private $iterations = array(); /** * The current priority of actively running iterations of a hook. * * @since 4.7.0 * @var array */ private $current_priority = array(); /** * Number of levels this hook can be recursively called. * * @since 4.7.0 * @var int */ private $nesting_level = 0; /** * Flag for if we're current doing an action, rather than a filter. * * @since 4.7.0 * @var bool */ private $doing_action = false; /** * Hooks a function or method to a specific filter action. * * @since 4.7.0 * * @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 * * @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 * * @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 * * @param string $tag Optional. The name of the filter hook. Used for building * the callback ID when SPL is not available. Default empty. * @param callable|bool $function_to_check Optional. The callback to check for. Default false. * @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 * * @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 * * @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 * * @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 * * @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 * * @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 * * @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 * @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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.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 * * @link https://secure.php.net/manual/en/iterator.rewind.php */ public function rewind() { reset( $this->callbacks ); } } Submit