JSON response from jQuery get raises "Invalid label"

       $.ajax({
  beforeSend: function(xhr) {
 xhr.setRequestHeader('Authorization', "Basic YWRtaW46YWRtaW4=");        
},
   url: "https://test.com/incident.do?JSON&callback=?&sysparm_action=getRecords",
   dataType: "json",
   contentType: "application/json",
   method: 'GET',
   success: function(a,b,c) { 
    alert(a);
         }          
 });

I call this function with a button press... Firebug shows that I get this JSON response (which I know is valid) [trun开发者_Go百科cated for clarity]

{
    "records": [
        {
            "service_offering": "",
            "number": "INC0000009"
        },
        {
            "service_offering": "",
            "number": "INC0000010"
        }
]
}

Firebug shows the error "invalid label https://test.com/incident.do?JSON&callback=jsonp1279049933243&sysparm_action=getRecords Line 1

How can I fix this? Thanks!

Your response is JSON, which is valid, but that's not what jQuery's looking for. When you specify &callback=? in the URL, jQuery is expecting a JSONP response, which looks different, your response should be

jsonp1279049933243({
  "records": [
    {
        "service_offering": "",
        "number": "INC0000009"
    },
    {
        "service_offering": "",
        "number": "INC0000010"
    }
  ]
});

What happens when you specify callback=? is that jQuery generates a name for your success function, in this case jsonp1279049933243, JSONP works by just generating a <script> tag in the page, so when it fetches that url, it's really just including a JavaScript file, running a function, but instead of this:

<script type="text/javascript">
  jsonp1279049933243({ "records": [....] });
</script>

What's effectively happening now is:

<script type="text/javascript">
  { "records": [....] }
</script>

...which isn't valid JavaScript. Now of course it's loaded via src=https://test.com/incident.do?JSON&callback=jsonp1279049933243&sysparm_action=getRecords, but the invalid syntax/label error is the same.

You may want to verify that the service supports jsonp. If not you'll need to set up a server side proxy.

Using jQuery to get json data returns invalid label error

You say that you know its valid. Can you funnel it into the parseJSON function and see if you have any luck with that?

$.parseJSON(str_json);

Note: You haven't mentioned which version of jQuery you're using. This method is available only in jQuery 1.4.1 and above.

Are you sure the json is valid? Check it validates at JSONLint.

try to get the data as a plain text and convert it into json on client side. I use "http://www.json.org/json2.js" script to do this. It helped me to resolve "invalid label" problem in my application. (I mentioned the script because eval() function didn't help, no idea why...)

good luck :)

If you are using 1.5.2 (and maybe older versions), you can disable jsonp if you do not need it or want it.

So for all ajax calls add this somewhere on your page:

$.ajaxSetup({
    jsonp: null,
    jsonpCallback: null
});

Or for just one call, add this:

jsonp: null,
jsonpCallback: null,

So in your example:

$.ajax({
    beforeSend: function(xhr) {
        xhr.setRequestHeader('Authorization', "Basic YWRtaW46YWRtaW4=");        
    },
    url: "https://test.com/incident.do?JSON&callback=?&sysparm_action=getRecords",
    dataType: "json",
    contentType: "application/json",
    method: 'GET',
    jsonp: null,
    jsonpCallback: null,
    success: function(a,b,c) { 
        alert(a);
    }          
});