app.js
/*
 * Delivery Confirmation Event
 *
 * This event is sent to confirm the delivery of a message. Read more about 
 * these fields at https://developers.facebook.com/docs/messenger-platform/webhook-reference/message-delivered
 *
 */
Delivery Confirmation Event
This event is sent to confirm the delivery of a message.
Delivery Confirmation Event This event is sent to confirm the delivery of a message .
function receivedDeliveryConfirmation(event) {
	var senderID = event.sender.id;
	var recipientID = event.recipient.id;
	var delivery = event.delivery;
	var messageIDs = delivery.mids;
	var watermark = delivery.watermark;
	var sequenceNumber = delivery.seq;
	if (messageIDs) {
		messageIDs.forEach(function (messageID) {
			console.log("Received delivery confirmation for message ID: %s",
				messageID);
		});
	}
	console.log("All message before %d were delivered.", watermark);
}
function receivedDeliveryConfirmation ( event ) { var senderID = event . sender . id ; var recipientID = event . recipient . id ; var delivery = event . delivery ; var messageIDs = delivery . mids ; var watermark = delivery . watermark ; var sequenceNumber = delivery . seq ; if ( messageIDs ) { messageIDs . forEach ( function ( messageID ) { console . log ( "Received delivery confirmation for message ID: %s" , messageID ) ; } ) ; } console . log ( "All message before %d were delivered." , watermark ) ; }
Delivery Confirmation Event
 This event is sent to confirm the delivery of a message.
Delivery Confirmation Event This event is sent to confirm the delivery of a message .