Comments on the oBIX Version 1.1 and JSON Encoding Public Drafts

[Matthias X Hub <matthias.hub@de.ibm.com>]

Dear all,

please find below some comments and
thoughts on the committee drafts. Additionally I've shared a proposal regarding
a possible oBIX WebSocket Binding, please see https://www.oasis-open.org/apps/org/workgroup/obix/download.php/50167
The comments related to the "WatchService" would enable the message
exchange pattern which is used in WebSocket based communication.

Re: oBIX Version 1.1 Committee Specification
Draft 01 / Public Review Draft 01 11 July 2013

Following text could be added to chapter 11 "Watches" to support
transient (or non-persistent) watches: 

The client can either 1) periodically poll the Watch URI using the pollChanges
operation to obtain the events which have occurred since the last poll
or 2) if the Watch was created with the makePush operation the updates
will be pushed to the client as they occur as long as the connection is
open.

WatchService is then composed of two operations:

<obj href="">
  <op name="make" in="obix:Nil" out="obix:Watch"/>
  <op name="makePush" in="obix:Nil" out="obix:Watch"/>
</obj>

WatchService.makePush creates a transient watch which will be deleted on disconnection of the client.

For an Watch object which was created by this operation the existing Watch operations have following semantics:
1) Watch.add: as the existing
2) Watch.remove: as the existing
3) Watch.pollChanges: will throw an err
4) Watch.pollRefresh: will throw an err
5) Watch.delete: will throw an err

Re: Encodings for oBIX: Common Encodings Version 1.0 Committee Specification Draft 01 / Public Review Draft 01 11 July 2013

We suggest
1) to call the structural element "items" instead of "nodes" because of the semantic meaning of the term "node" / "nodes" in HTML context (where JSON is usually used)
2) to call the tag element "type" instead of "tag" - as it seems to be more like a type than a tag, but I guess there are some edge cases where the "type" property is already used?
3) to fix the JSON examples, especially the quotes and comma after "tag" in the second and third line:

from:

{“tag”:”obj”, “href”:”/a/”, “nodes”:[
{“tag”,”obj”, “name”:”b”, “href”:”b”}, “nodes”:[
{“tag”,”obj”, “name”, “c”}, {“tag”,”ref”, “name”, “d”, “href”:”d”}, ]
}] }

to:

{
        "tag" : "obj",
        "href" : "/a/",
        "nodes" : [ {
                "tag" : "obj",
                "name" : "b",
                "href" : "b",
                "nodes" : [ {
                        "tag" : "obj",
                        "name" : "c"
                }, {
                        "tag" : "ref",
                        "name" : "d",
                        "href" : "d"
                } ]
        } ]
}

I am happy to receive your thoughts on my comments!

Mit freundlichen Grüßen / Best regards
Matthias Hub

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Solution Development Consultant IBM Connections and Smarter Home matthias.hub@de.ibm.com | +49-7034-643 x1261 | +49-160-7422995

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