[Standards-JIG] UPDATED: JEP-0059 (Result Set Management)

[Peter Saint-Andre]

Peter Saint-Andre wrote:
> Ian Paterson wrote:

<snip/>

>> An (optional?) addition to the protocol would enable another method that
>> does not suffer from any of the disadvantages above (except *). Perhaps
>> the responder could (optionally?) provide its opaque unique ordered ID
>> of the last item whenever it returns a result set page. (If provided)
>> this would allow the requestor to optionally specify the start of the
>> next page using the ID instead of the <start/> element (the first
>> returned element would be the one immediately *after* the specified ID).
>>
>> For example, JEP-0055 responder implementors might choose to return the
>> jid as the opaque ID:
>>    ...
>>    <set xmlns='http://jabber.org/protocol/rsm'>
>>      <max>10</max>
>>      <start>0</start>
>>      <last>woolly at sheep.com</last>
>>    </set>
>>
>> JEP-0055 requestor implementors could then use the opaque ID:
>>    <set xmlns='http://jabber.org/protocol/rsm'>
>>      <max>10</max>
>>      <after>woolly at sheep.com</after>
>>    </set>
> 
> Well, there's no real reason for <start/> then, is there? In the first
> request don't specify <after/>, in all other requests specify the unique
> ID (UID) of the last item.

I started to make these changes in JEP-0059 and I realized that it's not
necessarily straightforward to determine what the UID is for any given
payload. Making it payload-specific seems problematic -- how do the
requesting entity and responding entity know that the UID is the 'jid'
attribute of the <item/> element for jabber:iq:search, the 'jid' (or
maybe 'name') attribute for disco#items, etc.? It seems to me that we
need to have something like this:

Example 5. Requesting the First Page of a Result Set

<iq type='get' from='stpeter at jabber.org/roundabout'
to='users.jabber.org' id='page1'>
  <query xmlns='jabber:iq:search'>
    <first>Peter</first>
    <set xmlns='http://jabber.org/protocol/rsm'>
      <max>10</max>
    </set>
  </query>
</iq>

Example 6. Returning the First Page of a Result Set

<iq type='result' from='users.jabber.org'
to='stpeter at jabber.org/roundabout' id='page1'>
  <query xmlns='jabber:iq:search'
         xmlns:rsm='http://jabber.org/protocol/rsm'>
    <item jid='stpeter at jabber.org' rsm:uid='someid'>
      <first>Peter</first>
      <last>Saint-Andre</last>
      <nick>stpeter</nick>
    </item>
    .
    [8 more items]
    .
    <item jid='peterpan at neverland.lit' rms:uid='another-id'>
      <first>Peter</first>
      <last>Pan</last>
      <nick>petie</nick>
    </item>
    <set xmlns='http://jabber.org/protocol/rsm'>
      <max>10</max>
    </set>
    <count xmlns='http://jabber.org/protocol/rsm'>800</count>
  </query>
</iq>

Example 7. Requesting the Second Page of a Result Set

<iq type='get' from='stpeter at jabber.org/roundabout'
to='users.jabber.org' id='page2'>
  <query xmlns='jabber:iq:search'>
    <first>Peter</first>
    <set xmlns='http://jabber.org/protocol/rsm'>
      <max>10</max>
      <after>another-id</after>
    </set>
  </query>
</iq>

Am I missing something?

Peter

-- 
Peter Saint-Andre
Jabber Software Foundation
http://www.jabber.org/people/stpeter.shtml

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