Automattic\WooCommerce\Internal\Email

DeferredEmailQueue::push │ public │ WC 1.0

Add an email callback to the queue.

Returns false when any argument cannot be represented in Action Scheduler storage, allowing callers to fall back to sending the email synchronously.

Method of the class: DeferredEmailQueue{}

No Hooks.

Returns

true|false. True if the email was queued.

Usage

$DeferredEmailQueue = new DeferredEmailQueue();
$DeferredEmailQueue->push( $filter, $args ): bool;
$filter(string) (required)
The action hook name that triggered the email.
$args(array) (required)
The arguments passed to the action hook.

DeferredEmailQueue::push() code WC 10.9.1

woocommerce/src/Internal/Email/DeferredEmailQueue.php 
public function push( string $filter, array $args ): bool {
	try {
		$args = $this->prepare_arg_for_queue( $args );
	} catch ( \UnexpectedValueException $e ) {
		return false;
	}

	$this->queue[] = array(
		'filter' => $filter,
		'args'   => $args,
	);

	if ( ! $this->shutdown_registered ) {
		add_action( 'shutdown', array( $this, 'dispatch' ), 100 );
		$this->shutdown_registered = true;
	}

	return true;
}