[JDEV] PubSub (0060) Max_items -> Range?

[Matt Mankins]

In thinking about client interaction with pubsub nodes today I realized 
that it might sometimes be useful for clients to request a range of items 
from a node (this is modified example 50):

<iq type="get" from="pgm at jabber.org" to="pubsub.jabber.org" id="items2">
  <pubsub xmlns="http://jabber.org/protocol/pubsub">
    <items node="generic/pgm-mp3-player" range="10-20"/>
  </pubsub>
</iq>

We have max_items already, which suggests:

"When max_items is used, implementations SHOULD return the N most recent 
(as opposed to the N oldest) items."

...so there already exists a notion of "counting" to the items.

Range requests would be useful for low-bandwidth clients as well as for 
high-volume nodes.

Since range is actually more general than max_items, it might be 
preferable to replace max_items with range.  ie-- range="0-10" would be 
equivalent to the current max_items="10".



Matt Mankins
MIT Media Lab
http://www.media.mit.edu/~mankins/