Subj : Re: Equivalent of JS_InitClass for global object?
To   : netscape.public.mozilla.jseng
From : John J Lee <jjl@pobox.com>
Date : Mon Aug 25 2003 02:11 pm

On Sun, 24 Aug 2003, Brendan Eich wrote:

> John J. Lee wrote:
[...]
> The docs lie, they were written by some Netscape techwriter no longer
> around, who sometimes made up facts (probably frustrated by lack of
[...]

Thanks -- useful to know!  In the absence of a complete fix, maybe it
would be useful to add a health warning ('the embedding docs are
inaccurate in places')?

[...]
> >because, if a class isn't exposed outside the API, why else would one
> >want to call JS_InitClass unless one is *required* to call it on *all*
> >JSClass structures?
> >
>
> That doesn't follow at all.
>
> You can use a statically initialized JSClass struct by passing its
> address to JS_NewObject as the second parameter.  See js.c's 'glob =
> JS_NewObject(cx, &global_class, NULL, NULL);' without any prior or later
> JS_InitClass on that global_class struct.

Yeah, I found that and I know it doesn't follow -- I was just explaining
my thought processes to make it clear why I didn't understand the docs.
But it seems you already know the docs have problems.


> >I assume there's no reason to require "window" to *really* be the
> >global object?
> >
>
> There is if you want to run scripts from real-world web pages,
> especially those that know about multiple windows (frames in framesets,
> top-level windows).

I'll take your word for that, but I don't understand why (I *do* still
have window objects in Python -- it's just that rather than bind one
directly as the global object, I just have a function bind_window that
fakes a JS global object by grabbing the individual attributes and methods
from a window object and binding them to my simple JS global object).

What's the best way to find out about this kind of thing?  ATM, I don't
know, for example, whether all these frames / windows have their own
scopes / global objects / JSContexts -- your answer seems to hint at
something like this.  Am I stuck with either attempting to read the
Mozilla source, or guessing by looking at piles of real-world JS code?


John

.