Question

How can I keep the value of this when I go inside a function I lost the previous value of this

For example in this case how can I got the access to the testFunction.

admin = function()
{
    this.testFunction = function()
    {
    alert('hello');
    }

    this.test2Function = function()
    {
        $.ajax({
            url:'',
            success: function()
            {
                 this.testFunction();
                 // here I got an error undefined 
            }
        });
     }
}

I’ve tried to keep the value of this on a self var like this

this.self = this;

but not work

Answer 1

admin = function()
{
    var top = this;
    this.testFunction = function()
    {
    alert('hello');
    }

    this.test2Function = function()
    {
        $.ajax({
            url:'',
            success: function()
            {
                 top.testFunction();   // should work :)
            }
        });
     }
}

All local variables defined in a function, propagate (could be accessed) through WHOLE function, including all functions defined in that function.

So var top = this; will carry it’s value through all inner functions and objects declared inside of admin.