def _reduce(func, predicates: List['Predicate']) -> 'Predicate':
predicates = flatten_sequence(p for p in predicates if p is not None)
if not predicates:
return None
if len(predicates) == 1:
return list(predicates)[0]
else:
return reduce(func, predicates)
def where(self, *predicates: Tuple['Predicate'], indexed=False) -> 'Batch':
"""
Return a new batch, containing the resources whose attributes match the
given predicates, like `User.created_at >= cutoff_date`, for instance.
The new batch is *not* indexed by default, so make sure to set
`indexed=True` if you intend to filter the filtered batch further.
"""
predicate = Predicate.reduce_and(flatten_sequence(predicates))
resources = self._apply_indexes(predicate)
return type(self)(resources, indexed=indexed)
def on_decorate(self, handler: 'Action'):
event_type = handler.decorator.kwargs['event']
if event_type in KEY_EVENT_TYPES:
# look for action `key` attribute and add to "key" event handlers.
# otherwise add to "any key" event handlers.
key_obj = handler.decorator.kwargs.get('key')
if key_obj is not None:
for key in set(flatten_sequence(key_obj)):
self.key_event_handlers[event_type][key].append(handler)
else:
self.any_key_event_handlers[event_type].append(handler)
return
def where(self, *predicates, **equality_checks):
predicates = flatten_sequence(predicates)
for field_name, value in equality_checks.items():
resolver_prop = getattr(self.target, field_name)
pred = (resolver_prop == value)
predicates.append(pred)
if predicates:
if self.parameters.where:
self.parameters.where &= Predicate.reduce_and(predicates)
else:
self.parameters.where = Predicate.reduce_and(predicates)
return self
def including(self, *others) -> Predicate:
others = flatten_sequence(others)
visited = set()
deduplicated = []
for obj in others:
if is_resource(obj):
if obj._id not in visited:
visited.add(obj._id)
deduplicated.append(obj._id)
else:
if obj not in visited:
visited.add(obj)
deduplicated.append(obj)
return ConditionalPredicate(OP_CODE.INCLUDING, self, deduplicated)
def order_by(self, *order_by):
order_by = flatten_sequence(order_by)
if order_by:
self.parameters.order_by = []
for obj in order_by:
if isinstance(obj, OrderBy):
self.parameters.order_by.append(obj)
elif isinstance(obj, str):
if obj.lower().endswith(' desc'):
order_by_obj = OrderBy(obj.split()[0], desc=True)
else:
order_by_obj = OrderBy(obj.split()[0], desc=False)
if order_by_obj.key not in self.target.ravel.resolvers:
raise ValueError(
f'uncognized resolver: {order_by_obj.key}')
self.parameters.order_by.append(order_by_obj)
else:
self.parameters.order_by = None
return self
def deselect(self, *args):
"""
Remove the given arguments from the query's requests dict.
"""
args = flatten_sequence(args)
keys = set()
for obj in args:
if isinstance(obj, str):
# if obj is str, replace it with the corresponding resolver
# property from the target Resource class.
_obj = getattr(self.target, obj, None)
if _obj is None:
raise ValueError(f'unknown resolver: {obj}')
obj = _obj
elif is_resource(obj):
keys.update(obj.internal.state.keys())
continue
elif is_resource_type(obj):
keys.update(obj.ravel.resolvers.keys())
continue
# build a resolver request
request = None
if isinstance(obj, LoaderProperty) and (obj.decorator is None):
resolver_property = obj
keys.add(resolver_property.resolver.name)
elif isinstance(obj, ResolverProperty):
resolver_property = obj
keys.add(resolver_property.resolver.name)
elif isinstance(obj, Request):
request = obj
keys.add(request.resolver.name)
for key in keys:
if key in self.requests:
del self.requests[key]
return self
def select(self, *args):
args = flatten_sequence(args)
for obj in args:
if isinstance(obj, str):
# if obj is str, replace it with the corresponding resolver
# property from the target Resource class.
_obj = getattr(self.target, obj, None)
if _obj is None:
raise ValueError(f'unknown resolver: {obj}')
obj = _obj
elif is_resource(obj):
self.select(obj.internal.state.keys())
continue
elif is_resource_type(obj):
self.select(obj.ravel.resolvers.keys())
continue
# build a resolver request
request = None
if isinstance(obj, LoaderProperty) and (obj.decorator is None):
resolver_property = obj
request = Request(resolver_property.resolver)
elif isinstance(obj, ResolverProperty):
resolver_property = obj
request = Request(resolver_property.resolver)
elif isinstance(obj, Request):
request = obj
# finally set the request if one was generated
if request:
resolver_name = request.resolver.name
if resolver_name not in self.target.ravel.virtual_fields:
if self.from_request is not None:
request.parent = self.from_request
self.requests[request.resolver.name] = request
return self
def select(self, *args) -> 'Request':
from ravel.resolver.resolvers.loader import LoaderProperty
from ravel.resolver.resolver_property import ResolverProperty
args = flatten_sequence(args)
for obj in args:
if isinstance(obj, str):
# if obj is str, replace it with the corresponding resolver
# property from the target Resource class.
_obj = getattr(self.resolver.owner, obj, None)
if _obj is None:
raise ValueError(f'unknown resolver: {obj}')
obj = _obj
elif is_resource(obj):
self.select(obj.internal.state.keys())
continue
elif is_resource_type(obj):
self.select(obj.ravel.resolvers.keys())
continue
# build a resolver request
request = None
if isinstance(obj, LoaderProperty) and (obj.decorator is None):
resolver_property = obj
request = Request(resolver_property.resolver)
elif isinstance(obj, ResolverProperty):
resolver_property = obj
request = Request(resolver_property.resolver)
elif isinstance(obj, Request):
request = obj
if request is not None:
self.parameters.select.append(request)
elif obj is not None:
self.parameters.select.append(obj)
return self
def excluding(self, *others) -> Predicate:
others = flatten_sequence(others)
others = {obj._id if is_resource(obj) else obj for obj in others}
return ConditionalPredicate(OP_CODE.EXCLUDING, self, others)