jQuery插件中的全局变量

Question

I am creating a jquery plugin. In that am using some global variablse $.rmtableparams.recordsCount: 0 is one of them.

I am assigned some values to this from one function inside an ajax call .

 callAjax = function (surl, pselector, pi, rec) {
 $.ajax({
 ..
   success: function (data) {
           $.rmtableparams.recordsCount =10;
    }
  });
  }  

But while I am trying to access $.rmtableparams.recordsCount in some other function it returns 0. But strange thing is that if i alert anything before that it will returns 10 correctly.

Ie: if my script is

alert("hi");
alert($.rmtableparams.recordsCount);

the second alert will shows 10

But if only alert($.rmtableparams.recordsCount); is there it returns 0

I was wondered with this. If any body knows the reason please help me.

Answer 1

The assignment $.rmtableparams.recordsCount =10; is inside the success callback of an $.ajax request. So the value isn't assigned until the ajax call is completed, and a response received. This happens fairly quickly, so while you're first alert is waiting to be closed, the ajax response is received, and the assignment is processed. Then, the second alert shows the new value.

If you leave out the first alert, the call is still being processed and the $.rmtableparams.recordsCount value hasn't changed yet.
It's as simple as that: AJAX stands for Asynchronous JavaScript And XML. Async is key, but often overlooked...

Answer 2

You can't just go ahead and set $.rmtableparams.recordsCount because $.rmtableparams doesn't exist.

You first need to set $.rmtableparams :

$.rmtableparams = {};

Then you go ahead and add data to the object:

$.rmtableparams.recordsCount = 10;

Make sure that the success callback is being fired. Add an alert or console.log inside the callback to do the check.