Ajax async false is deprecated?

Question

I am using jQuery 1.7 and I use async:false for my AJAX requets, but I've learned that this function is deprecated.

I need to use callback but this doesn't work:

$("#form").submit(function(e) {
var cnf;

$.ajax({
    type: "POST", 
    url: 'page.php', 
    data: $('#form').serialize(),
    async: true,
    success: function(responseText) { 
        if(responseText.indexOf('err') != -1) {
            cnf = "error";
        } 
        else {
            cnf = "success";
        }
        return callBack( cnf );
    }, 
    error: function() {
        cnf = "error";  
        return callBack( cnf ); 
    } 
});


if(cnf == "success")
{
   alert('ok');
}
});

The HTML:

<form id="form">
 <input type="text" name="email">
 <input type="submit">
</form>

If I use async: false this works. Using callBack I see the solution here: wait for a jquery ajax callback from calling function

Anything that depends on the result of the AJAX call, *must* be in, called by, or (for events) attached by the callback of said AJAX call. — Niet the Dark Absol, Jun 12 '14 at 14:38
`async:false` is only deprecated when using deferred object method. To answer your issue, see: http://stackoverflow.com/questions/14220321/how-to-return-the-response-from-an-ajax-call — A. Wolff, Jun 12 '14 at 14:39
`1)` Never use `async: false`. Ever. Period. Get to know and love your callbacks and `jQuery promises` `2)` Any arguments about this, please see `1)` :) — iCollect.it Ltd, Jun 12 '14 at 14:50
Thanks you Bergi and @TrueBlueAussie but who i can use callback ? With callBack(cnf) is not work u have a simple example plz ? — user3710381, Jun 12 '14 at 15:10
If you show the surrounding function for this code, we can provide an example. The code is incomplete. e.g. where is `callBack` defined? — iCollect.it Ltd, Jun 12 '14 at 15:11
Its all i have just in if() alert('ok') and $(form).submit(...) i need with this "if(cnf == "success")" i need to go step 2 — user3710381, Jun 12 '14 at 15:27

Quentin · Answer 1 · 2014-06-12T14:49:24.903

5

From the documentation:

As of jQuery 1.8, the use of async: false with jqXHR ($.Deferred) is deprecated

You are not using it with jqXHR.

That said, non-async HTTP is horrible with JavaScript and best avoided. Do your work in or from the callback. Don't try to return data to the calling function so it can do the work.

edited Jun 12 '14 at 14:49

answered Jun 12 '14 at 14:39

Quentin

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2

I assume you meant "*sync HTTP is horrible*"? – Bergi Jun 12 '14 at 14:47
Yes thanks you Quentin i dont see its from jqXhr im new in javascript / jquery i use this simple method for a contact form – user3710381 Jun 12 '14 at 15:06

score 1 · Accepted Answer · answered Jun 12 '14 at 15:45

1

Continuing from the comments: You seem to be a little obsessed with callbacks, when you don't seem to need any! :)

The simple change to your existing code is to throw away cnf and simply put your code in the success part of the ajax call:

$("#form").submit(function (e) {
    $.ajax({
        type: "POST",
        url: 'page.php',
        data: $('#form').serialize(),
        async: true,
        success: function (responseText) {
            if (responseText.indexOf('err') != -1) {
                // Do something when it fails here
            } else {
                // Do something when it succeeds here!!!!
                alert('ok');
                // e.g. move on to "step 2"
            }
        },
        error: function () {
           // Do something when it fails here
        }
    });
});

answered Jun 12 '14 at 15:45

iCollect.it Ltd

92,391
25
181
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i dont have complet my code but i need to change
if step 1 is good (like a paiement system) 1: email, 2 name and address
– user3710381 Jun 12 '14 at 16:11
I have add all in one step :) – user3710381 Jun 12 '14 at 16:12
You need to show all your code to get a complete answer, but hopefully this has pointed you in the right direction. – iCollect.it Ltd Jun 12 '14 at 16:13

Ajax async false is deprecated?

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