Rails spinoffs - Jul 2006 - Sharing javascript between iframes

Hi,

I''m looking for a way to share prototype.js, and some of the 
scriptaculous stuff between multiple iframes on a single page, loading 
the javascript files once only, and in the parent page for this iframes.

Conventional wisdom might see me doing something like this from within 
the iframes to access the prototype functions...

var element = parent.$(''element_id'');

The problem of course with this, and this isn''t limited to prototype,
is
that the document keyword refers to the parent not the iframe, so for 
example, in the $ function, document.getElementById will look for an 
element with the id of ''element_id'' within the parent
document, not the
iframe.

One variation i''ve thought of is to pass in a reference to the iframe 
document to the function, so the $ function would look something like 
this...

var element  = parent.$(''element_id'', iframe);

The problem with this is that then means going through and changing 
every document keyword to a variable throughout prototype and would end 
up being pretty messy.

So, has anyone had any experience working with this kind of problem, or 
any ideas how to go about implementing this, and if so would you be kind 
enough to share your knowledge here?

The alternative would be to load prototype in the document content of 
the iframe, thus meaning multiple instances of prototype would be in 
existence. Is this such a bad thing, would it lead to a performance hit?

Thanks in advance for any help.

Cheers,
Mike.

On 7/24/06, Mike Rumble
<mike.rumble-nJYiJFE0GtnQXOPxS62xeg@public.gmane.org> wrote:
> The alternative would be to load prototype in the document content of
> the iframe, thus meaning multiple instances of prototype would be in
> existence. Is this such a bad thing, would it lead to a performance hit?
This is exactly what I''ve done. As long as you''re loading
prototype
from the same URL for both the parent window and the iframe, the
second one should be loaded from cache (though of course that depends
on your server sending the right headers), so there''s very little
overhead in that regard.

I''ve done this in two significant projects, and I didn''t
encounter any
significant performance issues once everything was loaded.

Seth