Hi,
I can't quite make out what you're trying to do, but I can tell you
why what you're doing isn't working: Function#bind[1] *returns* a new
bound function, it doesn't change the original function at all. Since
you're not assigning the return value to anything, it's not being
used.
You typically use #bind when you're passing a reference to a function
that needs to be called with a specific context (`this` value) into
something that doesn't provide any way for you to tell it what that
context should be (like an event handler). What #bind does is create a
new function that doesn't care what `this` value it's called with. The
new function, when called, turns around and calls the original
function with the `this` value you told it to use (as well as any
curried arguments and then the actual arguments it was called with).
Here's a classic event handler example:
$('someElement').observe('click', myObj.myMethod.bind(myobj));
The above uses #bind to create a function that, when called, will turn
around and call `myMethod` in the context of `myObj`. `myMethod` is
not changed in any way. The return value of #bind is passed in as the
handler. To make it a bit more explicit:
var handler = myObj.myMethod.bind(myobj);
$('someElement').observe('click', handler);
[1] http://api.prototypejs.org/language/function/prototype/bind/
HTH,
--
T.J. Crowder
Independent Software Engineer
tj / crowder software / com
www / crowder software / com
On Sep 18, 7:36 pm, kstubs <[email protected]> wrote:
> In my test class, I call show() method externally and then internally
> but the internal calls are not working when binding "this". The
> expected console results for the following implementation:
>
> _test = new test();
> _test.show('outer', 0);
> _test.hide('outer');
>
> EXPECTED CONSOLE LOG:
> show: outer
> show: inner
> show: inner no bind
> hide: inner
> hide: outer
>
> ACTUAL CONSOLE LOG:
> show: outer
> show: inner no bind
> hide: outer
>
> Here is my test class. Is there something wrong with the binding
> method?
>
> var test = Class.create({
> show: function(caller, itt)
> {
> console.log('show: ' + caller);
>
> if(itt == 0)
> {
> this.show.bind(this, 'inner', 1);
> this.show('inner no bind', 1);
> }
>
> if(itt == 1)
> this.hide.bind(this, 'inner', itt);
> },
> hide: function(caller)
> {
> console.log('hide: ' + caller);
>
> }
>
>
>
> });
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