Converting AJAX return data to JSON

Question

I am trying to retrieve data in a JSON object (which I have validated is correctly formatted) and output the data into the firebug console. I validated the JSON using JSONLint (http://jsonlint.com/) and know the data is not returning in JSON object because when I log it, it is logging as text rather than an object. When I look at the ajax post, there is a JSON tab and it shows the object, I just cannot retrieve it for some reason.

My ajax call is

    $.ajax({
        url:'/coords/base',
        data: { type: obj.type, id: obj.id },
        dataType:'text',
        type:'get',
        async:false,
        success: function(data) {
            console.log(data);
        }
    });

My return data looks like such:

    {   
        "1": {"name":"TEXT","coords":[        
            { "entry":3,"x":15,"y":15 }     
        ]}}

When I set the AJAX call to a variable and add .responseText; to the end of the call, I can retrieve the plaintext return of the AJAX call. I thought I could then just use $.serialize() or $.parseJSON() but then I get an error "uncaught exception: Syntax error, unrecognized expression."

The end goal would be to retrieve the content from this responseText and use the JSON object throughout my files. This call must be done synchronously because it loads in vital data.

Any help would be greatly appreciated.

How are you returning the data from the service? Is the response type application/json? — David Hoerster, Jun 06 '11 at 20:50
Does it make any difference if you remove the converters block? This: converters: {"text json": $.parseJSON()}. Because dataType:"json" should do it — Fredrik, Jun 06 '11 at 20:51
Why are you defining your own converter? JSON encoding is already built in and I think your provided converter is wrong. — Daff, Jun 06 '11 at 20:51
I have removed the converter and the updated current code is posted. — jslamka, Jun 06 '11 at 21:09
So how are you returning the data from your service? What language? Are you setting headers in the response? etc etc etc? Everything on the client looks OK and passcod's fiddle looks fine - so that's telling me that you have an issue on the service side. — David Hoerster, Jun 07 '11 at 13:11
Setting the header as application/json (header('Content-type: application/json');) on server side fixed the issue for me. — Vishwesh Shetty, Jan 21 '13 at 12:59

score 2 · Accepted Answer · answered Jun 06 '11 at 20:53

2

Explicitly instruct jQuery to treat the response as text:

$.ajax({
  // ...
  dataType: "text",
  // ...
});

You will then be able to get the JSON string. However, if you plan to convert it to a JS value thereafter, let me stop you: jQuery can do that for you automatically. If you specify the dataType to "json", or just let jQuery make an intelligent guess, the data argument passed to the success: function will be the parsed JSON object.

answered Jun 06 '11 at 20:53

Félix Saparelli

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I tried switching the data type to text (I had it set to json) and I still received the error. How disappointing :( – jslamka Jun 06 '11 at 21:07
@FélixSaparelli your link was very useful for me. Thanks – HaBo Oct 18 '11 at 18:11

score 1 · Answer 2 · edited May 23 '17 at 12:14

why not use $.getJson()

which is equivilant to

 $.ajax({
  url: url,
  dataType: 'json',
  data: data,
  success: callback
});

which you should then be able to do the following:

$.getJSON('file.json', function(data) {
$.each(data, function(i) {
       console.log(data[i]);
     });
    });

edit

perhaps, I am misunderstanding the problem.

EDIT #2 Perhaps this question would help: Is there a version of $getJSON that doesn't use a call back?

which suggests using this:

$.ajax({
    type: 'GET',
    url: 'whatever',
    dataType: 'json',
    success: function(data) { console.log(data);},
    data: {},
    async: false
});

which of course, looks like what you have, so I feel I need to step back and reanalyze the problem.

Using the getJSON() method is erroring out when I specify async: false. What I am trying to do with this data is store it in a variable to use outside of the success call. It is vital it happens synchronously but through an AJAX call. — jslamka, Jun 06 '11 at 21:06

Converting AJAX return data to JSON

2 Answers2

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