JSFiddle - React, Tailwind, and code Playground

HTML

<button id="button1">Button 1</button><br/>
<button id="button2">Button 2</button>

JavaScript

var onComplete = function(event, jqXHR, ajaxOptions) {
  alert("Requested with " + ajaxOptions.requestingObjectId);
};

var makeRequest = function() {
  var id = $(this).attr('id');
  $.ajax({
    url: '/echo/json/',
    data: {
      json: JSON.stringify({
        foo: 1
      }),
      delay: 0
    },
    requestingObjectId: id
  });
};

$('button').click(makeRequest);

$(document).ajaxStart(onComplete);