Understanding of ajax complete call

Question

I'm struggling with stabilizing Selenium automation for jQuery/AJAX application hence referred to

https://www.swtestacademy.com/selenium-wait-javascript-angular-ajax/

and it has ajaxComplete() method which has following code -

var callback = arguments[arguments.length - 1];
var xhr = new XMLHttpRequest();
xhr.open('GET', '/Ajax_call', true);
xhr.onreadystatechange = function() {
  if (xhr.readyState == 4) {
   callback(xhr.responseText);
  }
};
xhr.send();
);

I haven't work on JavaScript before and this code which I'm not able to understand completely. I've following questions with this, if someone can help to understand it -

What is Ajax_call in this? Is it generic call to check ajax completion? Or do I need to have my own endpoint there? If yes, does single end point enough or do I need to identify all calls and add them in the method?

Answer 1

Please check the documentation for XMLHttpRequest.open . If you do, you will the second argument listed is

url

A DOMString representing the URL to send the request to.

This means that it is simply the URL you want to request. I can be anything you want. The / prefix means that you are request relative to the root of the website (so if you are requesting from https://example.com/somedir/somepage the request will be made to https://example.com/Ajax_call .