jQuery Ajax - how to get response data in error

Question

I have a simple web application. I\'ve created the server REST API so it will return a response with HTTP code and a JSON (or XML) object with more details: application code

Answer 1

Here's an example of how you get JSON data on error:

$.ajax({
    url: '/path/to/script.php',
    data: {'my':'data'},
    type: 'POST'
}).fail(function($xhr) {
    var data = $xhr.responseJSON;
    console.log(data);
});

From the docs:

If json is specified, the response is parsed using jQuery.parseJSON before being passed, as an object, to the success handler. The parsed JSON object is made available through the responseJSON property of the jqXHR object.

Otherwise, if responseJSON is not available, you can try $.parseJSON($xhr.responseText).

Answer 2

directly from the docs

The jQuery XMLHttpRequest (jqXHR) object returned by $.ajax() as of jQuery 1.5 is a superset of the browser's native XMLHttpRequest object. For example, it contains responseText and responseXML properties, as well as a getResponseHeader()

so use the jqXRH argument and get the responseText property off it.

In the link above, look for the section entitled

The jqXHR Object

Answer 3

After spending so much time on this problem, I found the problem.

The page is under the URL: www.mydomain.com/register
The REST api is under the URL: server.mydomain.com/rest

Seems like this kind of POST is not so simple.
I'm going to search more information to understand this issue better (if you have more information please share it with me).

When putting the REST API under www.mydomain.com/rest - everything is working fine.

Answer 4

I also faced same problem when i was using multipart/form-data. At first I thought multipart/form-data created this mess, but later i found the proper solution.

1) JS code before:

var jersey_url = "http://localhost:8098/final/rest/addItem/upload";
var ans = $.ajax({
    type: 'POST',
    enctype: 'multipart/form-data',
    url: jersey_url,
    data: formData,
    dataType: "json",
    processData: false,
    contentType: false 
    success : funtion(data){
      var temp = JSON.parse(data);
      console.log("SUCCESS : ", temp.message);  
    }
    error : funtion($xhr,textStatus,errorThrown){
       console.log("ERROR : ", errorThrown);
       console.log("ERROR : ", $xhr);
       console.log("ERROR : ", textStatus);
    }
    });

Here when error occurred, it showed me this in console :-
Error :
Error : { abort : f(e), always : f(), .... , responseJSON :"{"message":"failed"}" }
Error : error

Thus i came to know that we have to use $xhr.responseJSON to get the string message which we sent from rest api.

2) modified/working error funtion:

error : funtion($xhr,textStatus,errorThrown){
        var string= $xhr.responseJSON;
        var json_object= JSON.parse(string);
        console.log("ERROR : ",  json_object.message);
    }

Thus will output "Error : failed" on console.