Package relationships

[dread]

Overview

Functionality to formally associate packages. We see a need for specific parent-child, inheriting or dependency relations. Not only should this help navigation between packages in the web interface, but it also provides a mechanism to automatically pull dependencies when downloading a data package, in a similar manner as we see in software package management.

Examples

1. There are 27 packages in data.gov.uk to do with the Data4NR's Health Poverty Index. There is currently no common link between these, unless you search for 'HPI' (which also brings up House Price Index), or look under tag 'health' (which also has 600 other results). There should be a link on each HPI package page to navigate to the other 'sibling' HPI packages, and to a 'root' package that has info about the set. This could be partially achieved using the existing tag or group concepts, but a more explicit/official/obvious marking of their relationship could be beneficial.

2. In ckan.net is freedict, a collection of translation dictionaries. You could make each dictionary a child package and use this system. But it would probably be better to make each dictionary a different resource in the same package. (There are other ideas to denote a resource as the data making up a 'portion' of package, or a 'whole' of the package, to help people downloading datasets in the software package style.)

3. OSM has had some Naptan data imported (bus stops), with special permission - i.e. a more liberal license. It would be useful to show this link on both OSM and Naptan packages in CKAN: OSM 'derives from' Naptan with a comment about the license change. I'm not sure this is useful to an automatic download or use of these datasets, but may aid exploration on the CKAN website and understanding the provenance of the bus stop data on it.

4. IPCC collection of data linked / mirrored. Not sure if there are useful relationships here?

5. Dracos gets postbox locations from crowd sourcing and OSM. We could say Dracos 'derives from' OSM.

See more examples discussed here: ​http://trac.ckan.org/ticket/253

Implementation

This is split into four tickets:

• Model: ticket:254
• Read in WUI: ticket:255
• Edit in WUI: ticket:256
• API: ticket:257

No need for write access to be provided API for the moment.

This ticket also encompasses ticket:169 (Package derivations) and ticket:176 (Package dependencies).

[dread]

Closing in favour of the 4 tickets it is split into.

[rgrp]

Re-opening as this is a useful meta-ticket and should only be closed when all subtickets done.