Subj : Re: Properties and Objects
To   : netscape.public.mozilla.jseng
From : "Sterling Bates" <sterlingb@bigbangmapsonco.com>
Date : Wed Dec 03 2003 10:46 am


"Joseph Smith" <eboli@hotdak.net> wrote in message
news:42ffeec1.0312030413.2824b09e@posting.google.com...
> Parent has an array of JSChilderen, when its created it creates a
> bunch of new JSChilderen, and i am trying to use getProperty() to
> simply tell the parent object to call the child objects output
> function (ie from a script, var p = new Parent(); p.child.output;)

Seems to me you just need () at the end of p.child.output.  All functions
have to be called with at least empty parentheses.

> I have included the classes to show you what i am trying to do, if you
> can explain how to pass in this fashion would be great help :)
> Also if you can exain how this happens can you also show me how to go
> from the static m_Childeren[0] that i am using for testing purposes,
> into an index generated from the calling function (ie var p = new
> Parent; p.child[40000].output) for example???

(Disclaimer before I continue: I'm not a C programmer.  Brendan could come
back and declare all of this to be wrong or the hard way to do things.)

The short way to accomplish this, as far as I know, is to make "child" an
array object:

    p = JS_NewArrayObject(cx, 0, NULL);
    JS_DefineProperty(cx, newProtoObj, "child", OBJECT_TO_JSVAL(p), NULL,
NULL, JSPROP_ENUMERATE);

Then allow script to create your children via

    p.child.push(new Child());

Then script can call

    p.child[40].output();

Next, create a non-classed function called CallOutputDebugString (dumb name,
yes):

    JSBool CallOutputDebugString(JSContext *cx, JSObject *obj, uintN argc,
jsval *argv, jsval *rval)
    {
        JSChild c = (JSChild *)JS_GetPrivate(cx, obj);
        c.OutputDebugString(cx, &rval);
    }

This function (CallOutputDebugString) replaces JSChild::OutputDebugString in
JSChild::Child_methods[].  Finally, you have to modify c.OutputDebugString
to something like this:

    JSBool JSChild::OutputDebugString(JSContext *cx, jsval *rval)
    {
        const char *output = "Test output";
        JSString *s = JS_NewStringCopyN(cx, output, 11);
        rval = STRING_TO_JSVAL(s);
    }

I hope that most of that is correct.  Someone'll correct what's wrong I'm
sure.  Good luck,

Sterling

.