[jsr-314-open] Adding an extension mechanism to the JavaScript event data payload

[Jim Driscoll]

And as long as I'm discussing the JavaScript event data payload, one 
thing that got stripped out during the specification process was the 
ability to extend the payload object in a compatible way.

At least one of the proposals I made was to simply prefix any property 
to the object that's implementation specific with a "x".   Another way 
could be defining a "extension" object that's a property of the data 
object, hanging all impl specific properties off of there.

If we don't have that extension mechanism, then adding something like a 
description property to that object becomes a compatability problem - 
since a future version of the spec may add a description property, 
breaking existing apps.

Again, I think that defining something like this could fall into an Errata.

Thoughts?

I've filed Issue 571 to track this issue.

https://javaserverfaces-spec-public.dev.java.net/issues/show_bug.cgi?id=571

Jim