Jquery ajax not able to load the script file

Question

jQuery.ajax({
    async: false,
    url: url,
    dataType: dataType,
    crossDomain: false
}).done(function(data) {
    callback(null, data);
}).fail(function(jqXHR, textStatus, errorThrown) {
    if (jqXHR.statusText === 'OK') {
        console.log('Unable to load resource:', url, 'error:', errorThrown);
    }
    callback(errorThrown)
});

For the above ajax request call i am facing some errors

Error 1: Request header field X-Requested-With is not allowed by Access-Control-Allow-Headers in preflight

Error 2: DOMException: Failed to execute 'send' on 'XMLHttpRequest': Failed to load

so is the client making the call to the server? in a quick google search for the first error pulled up this stack overflow question which might relatate — GoldenWest, May 01 '17 at 17:21
http://stackoverflow.com/questions/25727306/request-header-field-access-control-allow-headers-is-not-allowed-by-access-contr — GoldenWest, May 01 '17 at 17:21

score 0 · Answer 1 · answered May 01 '17 at 17:24

The server you're trying to hit is preventing the browser from completing the request via its HTTP access control policy (CORS). Specifically the "Access-Control-Allow-Headers".

You need to either:

Configure the server to allow "X-Requested-With" header, or:
Remove the "X-Requested-With" from jQuery's AJAX call

score 0 · Answer 2 · answered May 01 '17 at 17:26

0

Avoid synchronous requests. They are deprecated. Read this article on MDN.
You are facing the same-origin policy implemented by all web browsers. Since CORS is apparently not available for you, you should rely on JSONP.
If you want to load a script, it would be better to use jQuery.getScript().

answered May 01 '17 at 17:26

Badacadabra

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Thanks for your respose but i have tried with getScript but on success callback response i am getting undefined data even if the data is present. – Manjunath Davanam May 01 '17 at 18:02
"undefined data even if the data is present". What do you mean? What do you see in your dev tools? Do you have any warning or error message? – Badacadabra May 01 '17 at 18:06
it's very strange there is no error in console just giving undefined inside success callback – Manjunath Davanam May 01 '17 at 18:16

score 0 · Answer 3 · answered May 06 '17 at 18:30

I found the root cause when we make an ajax call to the js file with dataType = 'script'

when we mention dataType = 'script' it will evals the script data and returns the data inside the success callback. suppose if the js file is having any error during eval(js) it will find the error and it will returns undefined inside the success callback.

Jquery ajax not able to load the script file

3 Answers3