JQuery getJSON function

Question

I am using the following code to get the json feed of a twitter users friends using the twitter api :

var url = "http://twitter.com/statuses/friends/"+twitter_handle+".json?callback=?";

//show ajax loading animation
$('#loading').show();

$.getJSON(url, function(data) {
   //hide ajax loading animation 
   $('#loading').hide();
   //Processing the JSON here
   //...
});

This works when the twitter handle is valid.But if it is invalid,i.e. when no such twitter user exists the callback function i defined is not executed, and the ajax loading animation does not get hidden.

So, is there a way i can determine in code whether the request for the json feed is failing,and then hide the loading animation ?

Thank You.

score 1 · Answer 1 · answered Oct 22 '09 at 21:02

1

the ccallback can return 2 arguments one of which is a textStatus that you can test against.

$.getJSON(url, function (data, textStatus) {
  // data will be a jsonObj
  // textStatus will be one of the following values: 
  //   "timeout","error","notmodified","success","parsererror"
  this; // the options for this ajax request
}

via: http://docs.jquery.com/Ajax/jQuery.getJSON

answered Oct 22 '09 at 21:02

easement

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As far as I can see, that doesn't actually work: on success, textStatus is null; on failure, the function is never even called – Nov 04 '09 at 18:53

score 1 · Answer 2 · edited May 23 '17 at 11:48

You are not catching the error condition. From the example below you can use an if statement or a switch to handle both situations.

http://docs.jquery.com/Ajax/jQuery.getJSON says:

callback (Optional) Function
A function to be executed whenever the data is loaded successfully.

function (data, textStatus) {
  // data will be a jsonObj
  // textStatus will be one of the following values: 
  //   "timeout","error","notmodified","success","parsererror"
  this; // the options for this ajax request
}

Edit Working Example thanks go to jQuery ajax (jsonp) ignores a timeout and doesn't fire the error event.

        var twitter_handle = 'FakePersonx';
        var url = "http://twitter.com/statuses/friends/"+twitter_handle+".json?callback=?";

        $.jsonp({
            type: "GET",
            url: url,
            data: {},
            async:true,
            contentType: "application/json; charset=utf-8",
            dataType: "jsonp",
            success: function(data) {
                alert(data);
            },
            error: function (XMLHttpRequest, textStatus, errorThrown) {
                alert('error');
            },
            beforeSend: function (XMLHttpRequest) {
                alert('Before Send');
                $('#loading').show();
            },
            complete: function (XMLHttpRequest, textStatus) {
                alert('Complete');
                $('#loading').hide();
            }
});

Thanks for the reply Tony, but its not clear to me how adding the textStatus parameter to the callback function would help,as the function wont get executed if data is not loaded successfully. So how can i check the value of the textStatus variable ?. Can you please show some snippet to demonstrate...thank you. — rogerp, Oct 22 '09 at 21:17
Aparently there is a problem with how jquery handles jsonp. Thanks go to José Basilio here: http://stackoverflow.com/questions/1002367/jquery-ajax-jsonp-ignores-a-timeout-and-doesnt-fire-the-error-event I will edit my post with a working example. — Tony Heflin, Oct 23 '09 at 12:37

JQuery getJSON function

2 Answers2