pre_clear_scheduled_hook хук-фильтр . WP 5.1.0

Filter to preflight or hijack clearing a scheduled hook.

Returning a non-null value will short-circuit the normal unscheduling process, causing the function to return the filtered value instead.

For plugins replacing wp-cron, return the number of events successfully unscheduled (zero if no events were registered with the hook) or false if unscheduling one or more events fails.

Использование

add_filter( 'pre_clear_scheduled_hook', 'filter_function_name_255', 10, 3 );
function filter_function_name_255( $pre, $hook, $args ){
	// filter...

	return $pre;
}

$pre(null/массив)

Value to return instead.
По умолчанию: null to continue unscheduling the event

$hook(строка)

Action hook, the execution of which will be unscheduled.

$args(массив)

Arguments to pass to the hook's callback function.

Где вызывается хук

$pre = apply_filters( 'pre_clear_scheduled_hook', null, $hook, $args );

Где используется хук (в ядре WP)