javascript - Ajax onerror handler not working -

in pure javascript: make ajax request.

the server supposed return 410 error.

my code:

var ajax = new xmlhttprequest(); ajax.onload = displayxml; ajax.onerror = displayerror; ajax.open('get', 'http://myurl.com/request?param=1&param=2', true); ajax.send();  function displayerror(e) {     console.log(this.status); }  function displayxml() {     console.log(this.responsexml); } 

problem is, onerror function never gets called when http 410 returned. console says "get .... 410 (gone)" on line ajax.send() appears, calls displaypopularity. how should handle http errors, if can't use .onerror? mean, roll error handling displaypopularity thought there more elegant solution.

i believe onerror security issues (eg. cross-origin) or errors in "config" ajax (front-end).

"http errors" not considered "errors", "responses" server.

xmlhttprequest.onload executed, if there error in "http response":

try onreadystatechange if:

function displayxml() {     if (this.readystate == 4) //this line equivalent ajax.onload     {         if (this.status == 200) //detect http status response (200 = ok)         {            console.log(this.responsexml);         } else {//if 200 <> status = http error            console.log(this.status);        }     } }  var ajax = new xmlhttprequest(); //create obj ajax.open('get', 'http://myurl.com/request?param=1&param=2', true); //config request ajax.onreadystatechange = displayxml; //add event ajax.send(null); //send request