Subj : Constructor function cleanly failing
To   : netscape.public.mozilla.jseng
From : Matthew Mondor
Date : Mon Jan 10 2005 02:07 am

Hi all,

I was wondering if it is possible for a constructor function for a class
to return with an error to notify the script, although not causing
script execution to stop?  Must object creation with "new" always
succeed for a script to continue in ECMAScript?

What I tried was making a constructor return JS_FALSE, which causes the
script to be aborted.  I hence tried returning JS_TRUE after setting
JSVAL_VOID and JSVAL_NULL in rval and JS_TRUE, which didn't do the
trick...

If object constructor should not fail, I should at worse create a
useless object until some of its methods/functions is called to make it
useful, perhaps...

i.e.

var map;
map = new fileMap();
if (!map.map("fullpath"))
	...

As opposed to:

var map;
if (!(map = new fileMap("fullpath")))
	...

Thanks.
Matt

.