floof/lib/search.py

   1 from floof.model import Art, ArtUser, ArtUserType, Tag, TagText, User
   2
   3 def parse(search_string):
   4     """Parses a search query, and returns a query object on Art.
   5
   6     Queries can contain:
   7     - Regular tags: foo
   8     - User relations: by:kalu, of:eevee, for:ootachi
   9
  10     Later:
  11     - Negative versions of anything above: -by:eevee, -dongs
  12     """
  13
  14     # XXX doesn't do negative querying yet.
  15     # XXX could use some sane limits.
  16
  17     # We'll be building this as we go.
  18     q = Art.query
  19
  20     terms = search_string.split()
  21     for tag in terms:
  22         if ':' in tag:
  23             # This is a special tag; at the moment, by/for/of to indicate
  24             # related users
  25             prefix, tag = tag.split(':', 1)
  26
  27             # XXX what to do if this fails?  abort?  return empty query?
  28             target_user = User.get_by(name=tag)
  29
  30             if prefix == 'by':
  31                 rel = ArtUserType.BY
  32             elif prefix == 'for':
  33                 rel = ArtUserType.FOR
  34             elif prefix == 'of':
  35                 rel = ArtUserType.OF
  36             else:
  37                 # Bogus tag.  Not sure what to do here, so for the moment,
  38                 # ignore it
  39                 continue
  40
  41             # Inner join to the ArtUser table
  42             q = q.join(ArtUser, aliased=True) \
  43                  .filter(ArtUser.user == target_user) \
  44                  .filter(ArtUser.type == rel)
  45
  46         else:
  47             # Regular ol' tag
  48             q = q.join(Tag, TagText, aliased=True) \
  49                  .filter(TagText.text == tag)
  50
  51     return q