jQuery.getJSON doesn't trigger callback

Question

I have a html code:

<button>asd</button> <script type = "text/javascript"> $('button').click(     function() {         $.getJSON('/schedule/test/', function(json) {             alert('json: ' + json + ' ...');         });     } ); </script> 

and corresponding view:

def test(request):     if request.method == 'GET':         json = simplejson.dumps('hello world!')         return HttpResponse(json, mimetype = 'application/json') 

The view is executed (tested using print), json variable is initialised but no alert appears. What did I do wrong? I've already seen some docs on this (http://docs.jquery.com/Ajax/jQuery.getJSON#urldatacallback for example) but I didn't find an answer.

EDIT: The problem was, that HttpResponse was not imported... Unfortunately Django gave no error about it. Everything else was correct. regards
chriss

Answer 1

It is likely that the json is not properly formed. Sometimes this happens to me when my code, that should be producing json is generating an error. Two options:

• Use firebug to view the JSON response

• Setup error handling in your jquery code using the jQuery.ajaxSetup options such as:

    $.ajaxSetup({"error":function(XMLHttpRequest,textStatus, errorThrown) {          alert(textStatus);       alert(errorThrown);       alert(XMLHttpRequest.responseText);   }}); 

Using the error handling for debugging is great, since you will know immediately when there is a problem with your response. You can check out the jQuery documentation for jQuery.ajax which has all of the available options for jQuery.ajaxSetup.

EDIT: A third option would be to just open the URL that should be generating the JSON and run the output through JSON Lint to validate it.