[thelist] Javascript object / prototype question

[John Lauck]

Here's the script: http://recaffeinated.com/files/clawfoot.js

So much of it deals with jQuery's event and selector methods it might not
make as much sense unless you are aware of the jQuery API.

Here's an example (at line 467):

    bind_choosable_click_event: function() {
        var assigner = this;

        assigner.get_choosable().unbind('click').click(function() {
            var element = $j(this);
            var options = {
                id: assigner.assigner_element_numeric_id({element:
element}),
                element: element,
                type: assigner.assigner_element_type(element)
            };

            // passing the entire options obj to is_assigned here is okay,
but it might be less overhead if I just sent type and id
            if(assigner.is_assigned(options)) {
                assigner.unassign(options);
            }else{
                assigner.assign(options);
            }
        });
    },

You can see that `this` is replaced as soon as you open a function() {}, so
I save the current `this` in the `assigner` variable.  Otherwise I wouldn't
have a way to access it beyond that point (that I know of).  If this means
that I'm copying the current object into a new variable (recursively in a
way, since it's within itself) it could be creating a huge stack of code in
memory.  I hope I'm incorrect.  This is my first real attempt at creating a
large prototype/object so it's possible my code is rough.

Thanks,

John

On Jan 10, 2008 1:21 PM, Matt Warden <mwarden at gmail.com> wrote:

> On 1/10/08, John Lauck <recaffeinated at gmail.com> wrote:
> > Yes, that's the issue.  I use jQuery and as soon as you open another
> > function() { ...  } you can no longer use your `this` variable.  I
> assumed
> > that the new variable is just a reference, so it's not actually copying
> the
> > data to a new variable and that the reference is cleaned up when the
> > function ends.  Those are the two issues.  However, I've seen it used in
> > lots of scripts, so unless there's some sort of cleanup I'm unaware of?
>
> No, the only reason you would do this is because you do NOT want the
> reference to be cleaned up once the function ends. Otherwise you would
> just use 'this', right?
>
> Can you include more of your code?
>
> --
> Matt Warden
> Cincinnati, OH, USA
> http://mattwarden.com
>
>
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