Subj : Re: Object properties that dont yet exist?
To   : netscape.public.mozilla.jseng
From : genisiob@pilot.msu.edu (Brian)
Date : Tue Oct 07 2003 11:27 am

SOrry to reply to my own message, but I understand more now than when
I wrote this.  Now, I see that I can generate an AddProperty callback
when this is done, which gives me a big id number (1559158).  If I set
the value, I also get the SetProperty callback with the same big id
number.

Can I assume that the id will be the same, and use it as a generic
lookup number?  Is there anyway for me to determine the name of the
property that the script is creating?

Thanks,
Brian


genisiob@pilot.msu.edu (Brian) wrote in message news:<713f4923.0310070619.5f7be985@posting.google.com>...
> Hello all,
> 
> In Mozilla, if I run the following script, it works:
> 
> document.somejunk = 5;
> alert(document.somejunk);
> 
> How does this work?  The somejunk property of document surely was not
> defined in their model, yet the variable obviously gets added as a
> property of document for access.
> 
> I am implementing a javascript model where I want the same thing to
> happen... I want to have access to properties that I have not
> explicitly defined.
> 
> Now, if my object is something like this:
> 
> Foo = { int junk; int bar }
> 
> and a user sets Foo.somejunk, my error handler gets triggered, and the
> script aborts.
> 
> Instead, I want to have a catchall for the object, where I can store
> somejunk as a property.  Likewise, I want to catch somejunk as a
> property when it is being accessed, look up the value, and return
> it... much like the browser does.
> 
> How is this done?
> Thanks,
> Brian

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