Requests for comment/Image information

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Request for comment (RFC)
Image information
Component General
Creation date 2013-02-20
Author(s) MaxSem, Brion VIBBER, Yuvi Panda
Document status declined
General2013-02-20MaxSem, Brion VIBBER, Yuvi Panda

This proposal was obsoleted by Extension:CommonsMetadata and is now abandoned.

We need a facility to access information from file description pages in a machine-readable format. Bits of information needed are:

  • License information
  • Image description, in user's preferred language is possible
  • Author information
  • Date image was produced
  • Source of the image
  • etc

Commons already has a rich metadata system for Images, Artwork and Books - we should use it.

Storage: page_props vs. dedicated table[edit]

  • Some fields (e.g. license information HTML) can be quite large - is it desireable to store them in page_props? It currently uses BLOB for pp_value which can store up to 64k.
  • Some information (e.g. descriptions) might come in several languages. Storage options include: page_props with all languages packed into one blob or having a dedicated column for language in a separtate table? MaxSem leans towards the former option.

Query requirements[edit]

In the long term it would be nice to be able to do general queries, like "give me all the images with CC-BY-compatible license that are photographs from 1970 to present within this geo box". In the short term we do not need this. :)

In the short term, we need to be able to request the data for a specific file by name. We should also be able to ask for specific set of properties only - 'get me property X, Y, Z for item File:ABC.jpeg', rather than only 'get me all properties of item File:ABC.jpeg'.

Exposing data from a shared repo[edit]

  • How?
  • How important it is, do we need to implement it from the very beginning?

Proposed API draft[edit]

api.php?action=query&prop=filemetadata&fmdprop=description|licenseurl&fmdlanguage=ru

  • Allow selecting information in several languages or provide several fallback languages in case information in requested language is not found? Both?

Extension name[edit]

Please suggest something, or the most stupid name will be chosen:P

See also[edit]