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Source code for galaxy.managers.ratable
"""
Mixins for Ratable model managers and serializers.
"""
import logging
from typing import Type
from sqlalchemy.sql.expression import func
from galaxy.model import ItemRatingAssociation
from . import base
log = logging.getLogger(__name__)
[docs]class RatableManagerMixin:
rating_assoc: Type[ItemRatingAssociation]
[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:
[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:
[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:
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
}
})