[Woocommerce] Thêm Custom field vào trang checkout

Woocommerce.checkoutpage.customfield

add_action('init', 'ae_woocommerce_before_checkout_form');

function ae_woocommerce_before_checkout_form(){
	add_filter( 'woocommerce_checkout_fields', 'ae_woocommerce_checkout_fields' );
}

function ae_woocommerce_checkout_fields($checkout_fields){
	$checkout_fields['order']["new_comment"]	= array(
			'type' => 'textarea',
			'class' => array('notes'),
			'label' => __( 'Order Notes', 'woocommerce' ),
			'placeholder' => _x('Notes about your order, e.g. special notes for delivery.', 'placeholder', 'woocommerce')
		);
	return $checkout_fields;
}