[Bug 28740] New: Channel.I.Messages needs some way for clients to discover which headers are supported

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=28740

           Summary: Channel.I.Messages needs some way for clients to
                    discover which headers are supported
           Product: Telepathy
           Version: unspecified
          Platform: Other
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: tp-spec
        AssignedTo: telepathy-bugs at lists.freedesktop.org
        ReportedBy: will.thompson at collabora.co.uk
         QAContact: telepathy-bugs at lists.freedesktop.org


So. Message headers (and to a lesser extent body fields) fall into various
categories:

• CMs must set this header on messages; clients must not (e.g. scrollback,
message-sent, message-received)
• CMs must support this header; clients may set it (e.g. message-type)
• CMs may set this header on messages; clients must not set it (e.g.
message-token¹)
• CMs may support this header on messages; clients may set it (currently just
sender-nickname; this also applies to most of the headers I'm defining at the
moment like message-subject, supersedes (bug 25636), message-validity (SMS),
message-to/cc/bcc)

So the first two classes are unproblematic. CMs implement them, and clients can
look for them (and set them in the second case) or ignore them.

The third class is also okay, I think: CMs can implement them, and clients can
look for the header but just deal if it's missing, as with all headers.

The fourth class is a problem. How does the UI know that it's on MSN using
Butterfly, and hence can set sender-nickname? Ditto XMPP and message-subject;
Skype (and maybe ll-xmpp) and supersedes; etc.

I think the way to do this is to split the fourth set out in the spec, and have
a property listing which extra properties clients can set on outgoing messages
on this channel. (The property is immutable, but isn't requestable so doesn't
really fit in RCCs, which is a bit annoying.)

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.
You are the assignee for the bug.