Issues of using checkbox in CRM 2011

In a previous post I explained difference of using onChange and onClick in CRM 4.0

Now it has come the time to talk the same thing against CRM 2011. As same as 4.0, even in CRM 2011 we got only the onChange in native manner. As we all know the problem is you need to click somewhere else after clicking the checkbox to execute the event.  So we need to implement onClick to accomplish this. It is bit similar to  4.0, but there is a complication.

For some crazy reason, standard Xrm model that works for 2011 doesn’t work here and have to use the 4.0 style code. Other issue is execution take cyclic pattern and our code gets executed twice! So we need to change the focus as soon as we finish the code. Please check the working code (this should go in onload event);

MyCheckbox = function()
{
    crmForm.all.new_sample.onclick = function()
    {
       //Code
       //Change focus to another field  
    }
}

Issues are not finish yet! Practically, we might need to do something according to the value of the relevant check box. Biggest confusion comes here. Values given are completely opposite. When you check the checkbox you might get false instead of true and vice versa. Why this happens?

I am trying to understand it this way. (please correct me If I am wrong) This is not an error. We are executing the code on “click”. This doesn’t mean we have changed the value in the time we execute the code. Of course what we see is the "changed" situation through the form. Actually code happens for previous value of the check box. I think this is the reason Microsoft doesn’t provide this event in their native framework.

If we understand this, we are good to proceed with our work without any trouble. Only thing is do the opposite when playing around with the value of the checkbox upon onClick.

var _checkbox = Xrm.Page.getAttribute("new_sample").getValue();
if (_checkbox == true)
{ 
  //code for false 
}
else
{
  //code for true 
}

This is bit confusing.. but manageable.