callback function doesn't work when using getJSON function in jQuery

Question

I am trying to use the getJSON function in jQuery to import some data and trigger a callback function. The callback function doesn\'t run. However, if I try the same thing w

Answer 1

As mentioned by numerous others, you need valid JSON (i.e. complies with the rules at http://json.org/) for getJSON to work (this means you cannot get HTML via getJSON as in your example).

The reason the last test works is because the last parameter "json" is not being interpreted as the "type". Because the following does NOT work:

$("#test3").click(function() {
    $.get("index.html",
        '',
        function(response) {
                alert('hi');
                //works
        },
        "json"
    )
});

Answer 2

I had the same issue despite having well formed JSON etc. I was able to query my webservice, and get a response, however, my callback function wasn't firing. After scrounging the net, i most interwebers suggested using 'jsonp', which i did since my app performs some cross domain calls, and also added 'callback?' to my url. This didn't work but that including the callback with the returned JSON solved my problem. The code below explains what i mean:

//server side json formed somewhere up here
String data = callback + "("+ json +")" ;

the response resulting from this is something like "jsonp1280403476086([{"Name":"Jack Sparrow" which jQuery seemed to not have a problem and so never died on me.

Hope this helps.