RSS/ATOM feed for metadata changes

[lmika-bom]

Brought up during discussions with user of OpenWIS that is consuming metadata to produce derivative work.

At the moment, OpenWIS has a notion of "Whats New": a display of metadata record IDs that have been recently added or changed. It might be useful to set-up a machine readable version of this list --- something that users can subscribe to trigger automated processes when metadata changes. A good technology for providing this feature would be an RSS or ATOM feed.

Consider adding such a feed to the user portal. It might be necessary to add a number of feeds based on what updates the user wants to receive:

- Metadata types (non-stopgap metadata, all metadata)
- Update operations (newly added metadata, updated metadata)

[lmika-bom]

Note: it might be best to hold off on this task until work has begun on porting OpenWIS to Geonetworks 3.0

[lmika-bom]

Revisit for v4, if still relevant. There is an RSS feed on GeoNetworks but it only covers all metadata. That might be enough though.

[rogers492]

This issue was moved to OpenWIS/openwis4#43

[woollattd]

reopened since OpenWIS v3.x is in maintenance mode for next 6 years so this still applies