Question

I’m getting a syntax error (undefined line 1 test.js) in Firefox 3 when I run this code. The alert works properly (it displays ‘work’) but I have no idea why I am receiving the syntax error.

jQuery code:

$.getJSON('json/test.js', function(data) {     alert(data[0].test); }); 

test.js:

[{'test': 'work'}] 

Any ideas? I’m working on this for a larger .js file but I’ve narrowed it down to this code. What’s crazy is if I replace the local file with a remote path there is no syntax error (here’s an example):

http://api.flickr.com/services/feeds/photos_public.gne?tags=cat&tagmode=any&format=json&jsoncallback=?

Answer 1

I found a solution to kick that error

$.ajaxSetup({'beforeSend': function(xhr){     if (xhr.overrideMimeType)         xhr.overrideMimeType('text/plain');     } }); 

Now the explanation: In firefox 3 (and I asume only firefox THREE) every file that has the mime-type of ‘text/xml’ is parsed and syntax-checked. If you start your JSON with an ‘[‘ it will raise an Syntax Error, if it starts with ‘{‘ it’s an ‘Malformed Error’ (my translation for ‘nicht wohlgeformt’). If I access my json-file from an local script – no server is included in this progress – I have to override the mime-type… Maybe you set your MIME-Type for that very file wrong…

How ever, adding this little piece of code will save you from an error-message

Edit: In jquery 1.5.1 or higher, you can use the mimeType option to achieve the same effect. To set it as a default for all requests, use

$.ajaxSetup({ mimeType: 'text/plain' }); 

You can also use it with $.ajax directly, i.e., your calls translates to

$.ajax({     url: 'json/test.js',     dataType: 'json',     mimeType: 'textPlain',     success: function(data){         alert(data[0].test);     } });