I need to be able to page through pubsub items, and XEP-0059 (Result Set Management) seems like the Right Way to do this. In fact, it is even mentioned in XEP-0060 (see section 6.5.4), but underspecified.
Here are my thoughts: 1) The client should be able to provide an RSM section in an item retrieval request: <iq type="get" from="[email protected]/1" to="[email protected]" id="2"> <pubsub xmlns="http://jabber.org/protocol/pubsub";> <items node="activity"/> <set xmlns="http://jabber.org/protocol/rsm";> <max>3</max> </set> </pubsub> </iq> 2) The server should be able to provide an RSM section in the iq-result, per XEP-0060, 6.5.4. It could be argued that the server should be able to reply with a truncated list and an RSM section even if the client didn't provide an RSM section, but I wonder if that would affect existing client compatibility (clients not using RSM might always expect the full item list). 3) Use of RSM implies that there is a natural ordering of the items. However, if RSM is not used, then XEP-0060 does not say anything about item ordering. Probably this is because the default behavior of a retrieval request is to return ALL items, in which case the client can sort the items in whatever way it wants to. Then there is also max_items, which returns the "most recent" items. So, I think we need some clarifications: a) max_items and RSM do not mix. If the client provides both, then the server MUST prefer RSM. However, if the server does not support RSM, then it will honor max_items, but have no RSM section in the iq response. This makes it possible for the client to provide both mechanisms in a request, and be able to know which one was used by the server. b) if RSM is used by the server, then items are returned in a node-specific order. c) if max_items is used, then items are returned in modified descending order. d) if neither RSM nor max_items are used, then items are returned in unspecified order. What do others think? And where do we document this? Justin
