Oh, the melancholy

JSON is undefined in older browsers

Came up with the following error today, while trying to make a generalized way to invoke WebMethods from client side, using IE7:

PageServiceRequest invoke failed: 'JSON' is undefined

while doing something along the lines of this:

    
     function TextBoxValueChanged (successCallback, failureCallback, message) {
         try {
    var parms = [];
    for (var i = 2; i < arguments.length; i++) {
                                             parms.push(arguments[i]);
              }
    var options = {
                                             type: 'POST',
               contentType: 'application/json; charset=utf-8',
               data: JSON.stringify({
                typeName: 'Echo.App.Layouts.Benchmarking',
                methodName: 'BenchmarkingSaveMessage',
                args: parms}),
               dataType: 'json',
               url: '/_layouts/UserControlScriptMethod.aspx/PageServiceRequest',
               success: successCallback,
               error: failureCallback
              };
              $.ajax(options);
             }
   catch (e) {
              alert('PageServiceRequest invoke failed: ' + e.message);
             }
            }
 

And after browsing the internet relentlessly, finally found the solution here, and seemed like a nice way to start this blog. Apparently, newer browsers have built-in JSON support, whereas older browsers do not (that would explain I hadn't come up with this error before). All you have to do is download the js for JSON (json2.js) and include it in your page / master page / user control. And you have victory.

The function I present may be a little sketchy, but it will all come clear in my next post, about generalizing WebMethod invocation from client side. Let's hope I find a blogging tool before that :)