How to get response text asynchronously?

Question

I am trying to get the response text from an URL using ajax. The code below works fine if I set the async flag to false but I get a warning from jQuery saying

jquery.min.js:4 Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience.

Here is the code:

function verifyUser()
{
    var response = $.ajax({type: "GET", url: "/verify/4512h58", async: false}).responseText;
    console.log(response);
}

and if I set the async flag to true like so

var response = $.ajax({type: "GET", url: "/verify/112358", async: true}).responseText;

I get undefined as output. How to solve this?

score 2 · Accepted Answer · answered Apr 21 '17 at 19:27

2

This uses something called promises so it needs to look something like this...

var response = $.ajax({
  type: "GET",
  url: "/verify/4512h58"
}).done(function (response) {
  console.log(response);
});

See for more info

answered Apr 21 '17 at 19:27

Shaun Sweet

669
5
9

score 1 · Answer 2 · edited May 23 '17 at 12:34

1

Use the callback

var response = "";
$.ajax({type: "GET", url: "/verify/112358", async: true})
     .then(function(x){
        response = x.responseText
     });

See also How do I return the response from an asynchronous call?

edited May 23 '17 at 12:34

Community

1
1

answered Apr 21 '17 at 19:26

Igor

60,821
10
100
175

With 20k rep you should know to flag this over asked question as a duplicate rather than answering it again – andrew Apr 21 '17 at 19:29
@andrew - I did, see the comment below the question. – Igor Apr 21 '17 at 19:30
So... you just wanted to make it more difficult to delete? – Heretic Monkey Apr 21 '17 at 19:40
@MikeMcCaughan - questions are not deleted frequently and especially not if its a true duplicate. Instead it will get marked as such but hang around in the system. – Igor Apr 21 '17 at 19:42
I thought they got picked up by the Roomba, but apparently that doesn't include duplicates. My apologies. – Heretic Monkey Apr 21 '17 at 20:09

How to get response text asynchronously?

2 Answers2