I am a beginner and been playing around with some js code. First I would like to know what this line of code exactly does. Let's assume n is some variable. My understanding was, that it sends a http request to herokuapp with the data of interest "n". How is that data incorporated?
const Http = new XMLHttpRequest();
const url='https://myapp.herokuapp.com/?data='+n;
Http.open("GET", url);
Http.send();
What is the most simple way to accept and log the data n in my heroku app?
Thanks in advance!
The code above sends a HTTP GET request to the application running at myapp.herokuapp.com passing a parameter called data with whatever value the variable n holds.
On Heroku typically you deploy an application (service) than can listen and process HTTP requests. You can use any language (JS, Python, Java, etc..) since they all are suitable to implement a web service.
Using NodeJS you would do something like:
const express = require('express');
const app = express();
app.get('/', (req, res) => {
const data = req.query.data // grab parameter
console.log(`Value of data is ${data}`);
res
.status(200)
.send('Ok')
.end();
});
// Start the server
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
console.log(`App listening on port ${PORT}`);
});
Checkout NodeJS on Heroku to see how you setup and deploy a NodeJS application.