On 10/3/2009 1:06 AM, Mads Randstoft wrote:
Brett Zamir<[email protected]> Wrote:
While attributes are being added to<item/>, would there also be some
way to add meta-data about the node to the event as well, e.g.,
pubsub#num_subscribers (the number of subscribers to the node) or
pubsub#title (human-readable node name)? I know it can be retrieved
separately, but this seems it could be useful to be able to get back
together...
I would say this could be added as a configuration option for node?
Adding some data as meta data to a published item?
As I imagine the system, it would be sort of individual and discoverable
implementation specific.
That sounds like an interesting approach... Another (which could
co-exist with your node configuration idea if the latter were treated
instead as being obtainable under the new retrievable default
subscription options) might be to let it be decided via subscription
options. A client which wished to use the meta-data could therefore get
it delivered in a way which suited its interface options and user
preferences.
In either scenario, the option could be of type list-multi, to allow
flexible specification of exactly which meta-data was desired.
This might be both more powerful and flexible, in allowing clients and
users to come up with their own use of meta-data as perhaps not
anticipated by the server administrators, as well as more economical
than sending all meta-data automatically if there was no desire for it
(which could add up to a lot if it is being attached to each notification).
To mitigate the fact that at least some meta-data is unlikely to change
(e.g., pubsub#creation_date indicating when the node was created) and
could be discovered immediately after initial subscription (currently by
a meta-data discovery request), perhaps even the subscription
confirmation could be made to return such fixed meta-data (as child XML)
so that clients could be aware of node support for such fixed meta-data
(without making an extra request or needing to receive the meta-data
with each notification delivery). The clients would thus be able to
retain and associate such non-altering data corresponding to each node
to which the user subscribed, so that they would only need to configure
their subscription options to receive the more frequently changing
meta-data which they desired (e.g., #num_subscribers).
Brett
