Question

What if I want to access actual this variable of a function when it was when created? this can be substituted like in the code below and I need to have a temporary this1 variable in two samples of access. Is it possible not to use temporary variable?

<input id="mybutton" type="button" value="Press Me"/>

<script type="text/javascript">

function Widget() {

    var this1 = this;
    this.mybutton = $("#mybutton");
    this.waspressed = false;

    this.onMyButtonPressed1 = function() {
        $(this).val("Enough");
        this.waspressed = true;
        alert("this.waspressed = " + this.waspressed + ", this1.waspressed = " + this1.waspressed);
    };

    this.onMyButtonPressed2 = function() {
        this.mybutton.val("Enough");
        this.waspressed = true;
        alert("this.waspressed = " + this.waspressed + ", this1.waspressed = " + this1.waspressed);
    };

    this.mybutton.click( this.onMyButtonPressed1 );
    /*
    this.mybutton.click( function() {
        this1.onMyButtonPressed2();
    });
    */

}

$(document).ready( 
    function() { 
        a = new Widget(); 
    } 
);

</script>

</body>

Answer 1

The this value is bound on every function call, so if you want to preserve what it was in an enclosing function for use in a nested function the only thing to do is make a copy in a closure variable (like “this1”).

To put it another way, you cannot force the runtime system to not bind this to something when a function is called.