Login on the front-end side using AJAX

token-frontend.js

// To be used to set a cookie
function setCookie(cname, cvalue, exdays) {
  var d = new Date();
  d.setTime(d.getTime() + (exdays * 86400000));
  var expires = "expires="+d.toUTCString();
  document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

// Login through an AJAX call
function login(username, password) {
  let xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      setCookie("token", this.responseText, 100);
      setCookie("username", username, 100);
      console.log('Success');
    } else if(this.readyState == 4 && this.status == 403) {
      console.error('Failure');
    }
  };
  xhttp.open("GET", "login?username=" + username + "&password=" + password, true);
  xhttp.send();
}