NEW ISSUE: How to enable extensibility to multiple bindings on achannel

[Eric Johnson <eric@tibco.com>]

Target: 1.2 WD 01 + resolution of issue 241

Title: How to best allow for an implementation to extend channels to allow for multiple bindings.

Description:

At the September 2010 Face-To-Face meeting in Portland, we decided that channels, at least as defined in the standard, can have but one binding element.

The problem is that some implementations may wish to support multiple bindings on a single channel.  At the moment, they can do so by defining extension elements.  The cost here is that if an SCA end-user attempts to move that composite to another implementation, those extension elements may be discarded, rather than being recognized as fundamentally incompatible or different.

Proposal:

One possible solution to resolve this is to make the channels themselves the extension point, so as to enable implementations to explicitly model and constrain what might appear under the "channel" element in serialized form.  That is, instead of "channel", we could define "channel.sca", and allow for "channel.other".