Subj : Re: Array Object index question
To   : netscape.public.mozilla.jseng
From : cburdon@tampabay.rr.com (Izman)
Date : Tue Oct 28 2003 09:03 am

Ok... I obviously asked the wrong questions in the wrong manner. 
<Pulls out his giant eraser and rubs out his first post>

First of all let me say "Thank you" to you Brendan.  I am sure you are
very busy and any time you take to answer posts in this newsgroup is
greatly appreciated, especially by me since I am in no way a C++ or js
engine guru by any stretch of the imagination.

I will start by stating I am using Spidermonkey 1.5-rc5a on a Windows
XP machine with MSVS6.

I have been working on a solution to the problem I mentioned in the
first post, although I didn't really articulate my goals very well. 
Ultimately what I thought I needed was an array accessible in
javascript that was (in effect) linked to an array of structs in my C
code.  What I found out was, I was wrong.

After many hours of testing and thinking, more testing and thinking,
and then even more testing and thinking (about 1000 more times), I
finally came up with what I hope to be the solution to my problem.

I have an object (JSObject1).  I added a method to the object that
returns another  object (JSObject3).  JSObject3 has a private member
variable (m_Index) that holds the array index of the struct member it
is assigned to access and is set by a public member function named
SetIndex.  The method I implemented is as follows:

JSBool JSObject1::obj3(JSContext *cx, JSObject *obj, uintN argc, 
					  jsval *argv, jsval *rval)
{
	long iIndex = 0;

	if (JSVAL_IS_INT(*argv)) { 
		JS_ValueToInt32(cx, *argv, &iIndex);
	} else if (JSVAL_IS_STRING(*argv)) { 
		// The next line is just for testing purposes.
		iIndex = strlen(JS_GetStringBytes(JSVAL_TO_STRING(*argv)));
	}

	JSObject *newObj = JS_ConstructObject(cx, &JSObject3::object3Class,
NULL, NULL);

	JSObject3 *p = (JSObject3*)JS_GetPrivate(cx, newObj);

	p->SetIndex(iIndex);

	*rval = OBJECT_TO_JSVAL(newObj);

	return JS_TRUE;
}

This method (in my testing) accomplishes my goals.  The method allows
me to access the properties of a JSObject3 object (such as a property
named prop1) through javascript, as in:

	Object1.obj3(2).prop1 

My concern is that garbage collection may negatively impact the script
or that this may cause some type of memory leak.  Obviously there is
some error checking that could occur in the function.  Sans error
checking, could someone please let me know if there is anything
inherently incorrect with my solution?

Thank you in advance for any help that is provided.

Izman

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