WP_Hook::apply_filters │ public │ WP 4.7.0

Calls the callback functions that have been added to a filter hook.

Method of the class: WP_Hook{}

No Hooks.

Returns

Mixed. The filtered value after all hooked functions are applied to it.

Usage

$WP_Hook = new WP_Hook();
$WP_Hook->apply_filters( $value, $args );

$value(mixed) (required)

The value to filter.

$args(array) (required)

Additional parameters to pass to the callback functions. This array is expected to include $value at index 0.

Changelog

WP_Hook::apply_filters() WP Hook::apply filters code ^{WP 6.9}

public function apply_filters( $value, $args ) {
	if ( ! $this->callbacks ) {
		return $value;
	}

	$nesting_level = $this->nesting_level++;

	$this->iterations[ $nesting_level ] = $this->priorities;

	$num_args = count( $args );

	do {
		$this->current_priority[ $nesting_level ] = current( $this->iterations[ $nesting_level ] );

		$priority = $this->current_priority[ $nesting_level ];

		foreach ( $this->callbacks[ $priority ] as $the_ ) {
			if ( ! $this->doing_action ) {
				$args[0] = $value;
			}

			// Avoid the array_slice() if possible.
			if ( 0 === $the_['accepted_args'] ) {
				$value = call_user_func( $the_['function'] );
			} 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, $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;
}