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Source code for galaxy.managers.ratable

"""
Mixins for Ratable model managers and serializers.
"""

from sqlalchemy.sql.expression import func
from . import base

import logging
log = logging.getLogger( __name__ )


[docs]class RatableManagerMixin( object ): #: class of RatingAssociation (e.g. HistoryRatingAssociation) rating_assoc = None
[docs] def rating( self, item, user, as_int=True ): """Returns the integer rating given to this item by the user. Returns the full rating model if `as_int` is False. """ rating = self.query_associated( self.rating_assoc, item ).filter_by( user=user ).first() # most common case is assumed to be 'get the number' if not as_int: return rating # get the int value if there's a rating return rating.rating if rating is not None else None
[docs] def ratings( self, item ): """Returns a list of all rating values given to this item.""" return [ r.rating for r in item.ratings ]
[docs] def ratings_avg( self, item ): """Returns the average of all ratings given to this item.""" foreign_key = self._foreign_key( self.rating_assoc ) avg = self.session().query( func.avg( self.rating_assoc.rating ) ).filter( foreign_key == item ).scalar() return avg or 0.0
[docs] def ratings_count( self, item ): """Returns the number of ratings given to this item.""" foreign_key = self._foreign_key( self.rating_assoc ) return self.session().query( func.count( self.rating_assoc.rating ) ).filter( foreign_key == item ).scalar()
[docs] def rate( self, item, user, value, flush=True ): """Updates or creates a rating for this item and user. Returns the rating""" # TODO?: possible generic update_or_create # TODO?: update and create to RatingsManager (if not overkill) rating = self.rating( item, user, as_int=False ) if not rating: rating = self.rating_assoc( user=user ) self.associate( rating, item ) rating.rating = value self.session().add( rating ) if flush: self.session().flush() return rating
# TODO?: all ratings for a user
[docs]class RatableSerializerMixin( object ):
[docs] def add_serializers( self ): self.serializers[ 'user_rating' ] = self.serialize_user_rating self.serializers[ 'community_rating' ] = self.serialize_community_rating
[docs] def serialize_user_rating( self, item, key, user=None, **context ): """Returns the integer rating given to this item by the user.""" if not user: raise base.ModelSerializingError( 'user_rating requires a user', model_class=self.manager.model_class, id=self.serialize_id( item, 'id' ) ) return self.manager.rating( item, user )
[docs] def serialize_community_rating( self, item, key, **context ): """ Returns a dictionary containing: `average` the (float) average of all ratings of this object `count` the number of ratings """ # ??: seems like two queries (albeit in-sql functions) would slower # than getting the rows and calc'ing both here with one query manager = self.manager return { 'average' : manager.ratings_avg( item ), 'count' : manager.ratings_count( item ), }
[docs]class RatableDeserializerMixin( object ):
[docs] def add_deserializers( self ): self.deserializers[ 'user_rating' ] = self.deserialize_rating
[docs] def deserialize_rating( self, item, key, val, user=None, **context ): if not user: raise base.ModelDeserializingError( 'user_rating requires a user', model_class=self.manager.model_class, id=self.serialize_id( item, 'id' ) ) val = self.validate.int_range( key, val, 0, 5 ) return self.manager.rate( item, user, val, flush=False )
[docs]class RatableFilterMixin( object ): def _ratings_avg_accessor( self, item ): return self.manager.ratings_avg( item ) def _add_parsers( self ): """ Adds the following filters: `community_rating`: filter """ self.fn_filter_parsers.update({ 'community_rating': { 'op': { 'eq' : lambda i, v: self._ratings_avg_accessor( i ) == v, # TODO: default to greater than (currently 'eq' due to base/controller.py) 'ge' : lambda i, v: self._ratings_avg_accessor( i ) >= v, 'le' : lambda i, v: self._ratings_avg_accessor( i ) <= v, }, 'val' : float } })