Facebook messenger that sends a message manually if the user subscribed - facebook-messenger

Question

I'm making a bot that let my students get a school meal menu. I'd like it to send a list of menu to students 10 minutes before the lunch time.
How should I make a code for this in JavaScript?
The main problem I encountered with was how to check the time so that my bot can send a message at that time.
I also wonder if its code always runs on the Facebook server, so I can use while loop that always check a time.
I'd appreciate an advice. (I use MongoDB and node)
var express = require("express");
var request = require("request");
var bodyParser = require("body-parser");
var hey = ["Yeah! 😃"]
var reply;
var app = express();
app.use(bodyParser.urlencoded({extended: false}));
app.use(bodyParser.json());
app.listen((process.env.PORT || 5000));
app.get("/", function (req, res) {
res.send("Deployed!");
});
app.get("/webhook", function (req, res) {
if (req.query["hub.verify_token"] === process.env.VERIFICATION_TOKEN) {
console.log("Verified webhook");
res.status(200).send(req.query["hub.challenge"]);
} else {
console.error("Verification failed. The tokens do not match.");
res.sendStatus(403);
}
});
app.post('/webhook', function (req, res) {
var data = req.body;
if (data.object === 'page') {
if(d.getHours() === 10 && d.getMinutes() === 5)
sendTextMessage(senderID, "Success!");
data.entry.forEach(function(entry) {
var pageID = entry.id;
var timeOfEvent = entry.time;
entry.messaging.forEach(function(event) {
if (event.message) {
receivedMessage(event);
} else if(event.postback){
receivedPostback(event);
}
else {
console.log("Webhook received unknown event: ", event);
}
});
});
res.sendStatus(200);
}
});
function receivedMessage(event) {
var senderID = event.sender.id;
psid = senderID;
var recipientID = event.recipient.id;
var timeOfMessage = event.timestamp;
var message = event.message;
console.log("Received message for user %d and page %d at %d with message:",
senderID, recipientID, timeOfMessage);
console.log(JSON.stringify(message));
var messageId = message.mid;
var messageText = message.text;
var messageAttachments = message.attachments;
if (messageText) {
switch (messageText) {
case 'Check':
sendTextMessage(senderID, "isSub: " + isSub);
sendTextMessage(senderID, "gamerNumber: " + gamerNumber);
sendTextMessage(senderID, "psid: " + senderID);
break;
----(and more)
function sendGenericMessage(recipientId, payload) {
var titlee
var subs
var image
switch(payload){
case "pmorning":
titlee = "Breakfast"
subs = //***this is the part where the db value goes in.***
image = "https://cdn.arstechnica.net/wp-content/uploads/sites/3/2016/10/Oculus-Rift-vs-HTC-Vive-vs-PlayStation-VR-1.jpg"
break;
---and more
}]
}]
}
}
}
};
sendTypingOn(recipientId);
callSendAPI(messageData);
}

Answer 1

Take a look at node-cron, which enables you to schedule jobs for running at specific times, specified by a CRON expression