sqlalchemy.orm.attributes.CollectionAttributeImpl

class documentation

class CollectionAttributeImpl(AttributeImpl):

A collection-holding attribute that instruments changes in membership.

Only handles collections of instrumented objects.

InstrumentedCollectionAttribute holds an arbitrary, user-specified container object (defaulting to a list) and brokers access to the CollectionAdapter, a "view" onto that object that presents consistent bag semantics to the orm layer independent of the user data implementation.

Method	`__copy`	Undocumented
Method	`__init__`	Construct an AttributeImpl.
Method	`_default_value`	Produce an empty collection for an un-initialized attribute
Method	`_dispose_previous_collection`	Undocumented
Method	`_initialize_collection`	Undocumented
Method	`_invalidate_collection`	Undocumented
Method	`append`	Undocumented
Method	`delete`	Undocumented
Method	`fire_append_event`	Undocumented
Method	`fire_append_wo_mutation_event`	Undocumented
Method	`fire_pre_remove_event`	A special event used for pop() operations.
Method	`fire_remove_event`	Undocumented
Method	`get_all_pending`	Return a list of tuples of (state, obj) for all objects in this attribute's current state + history.
Method	`get_collection`	Retrieve the CollectionAdapter associated with the given state.
Method	`get_history`	Undocumented
Method	`pop`	Undocumented
Method	`remove`	Undocumented
Method	`set`	Undocumented
Method	`set_committed_value`	Set an attribute value on the given instance and 'commit' it.
Class Variable	`__slots__`	Undocumented
Class Variable	`collection`	Undocumented
Class Variable	`default_accepts_scalar_loader`	Undocumented
Class Variable	`dynamic`	Undocumented
Class Variable	`supports_population`	Undocumented
Class Variable	`uses_objects`	Undocumented
Instance Variable	`_append_token`	Undocumented
Instance Variable	`_bulk_replace_token`	Undocumented
Instance Variable	`_duck_typed_as`	Undocumented
Instance Variable	`_remove_token`	Undocumented
Instance Variable	`collection_factory`	Undocumented
Instance Variable	`copy`	Undocumented

Inherited from AttributeImpl:

Method	`__str__`	Undocumented
Method	`_fire_loader_callables`	Undocumented
Method	`_get_active_history`	Backwards compat for impl.active_history
Method	`_set_active_history`	Undocumented
Method	`get`	No summary
Method	`get_committed_value`	return the unchanged value of this attribute
Method	`hasparent`	Return the boolean value of a `hasparent` flag attached to the given state.
Method	`sethasparent`	Set a boolean flag on the given item corresponding to whether or not it is attached to a parent object via the attribute represented by this `InstrumentedAttribute`.
Class Variable	`active_history`	Undocumented
Instance Variable	`_deferred_history`	Undocumented
Instance Variable	`_modified_token`	Undocumented
Instance Variable	`accepts_scalar_loader`	Undocumented
Instance Variable	`callable_`	Undocumented
Instance Variable	`class_`	Undocumented
Instance Variable	`dispatch`	Undocumented
Instance Variable	`is_equal`	Undocumented
Instance Variable	`key`	Undocumented
Instance Variable	`load_on_unexpire`	Undocumented
Instance Variable	`parent_token`	Undocumented
Instance Variable	`send_modified_events`	Undocumented
Instance Variable	`trackparent`	Undocumented

def __copy(self, item):

Undocumented

def __init__(self, class_, key, callable_, dispatch, typecallable=None, trackparent=False, copy_function=None, compare_function=None, **kwargs):

overrides sqlalchemy.orm.attributes.AttributeImpl.__init__

Construct an AttributeImpl.

Parameters
class_	associated class
key	string name of the attribute
callable_	optional function which generates a callable based on a parent instance, which produces the "default" values for a scalar or collection attribute when it's first accessed, if not present already.
dispatch	Undocumented
typecallable	Undocumented
trackparent	if True, attempt to track if an instance has a parent attached to it via this attribute.
copy_function	Undocumented
compare_function	a function that compares two values which are normally assignable to this attribute.
**kwargs	Undocumented
active_history	indicates that get_history() should always return the "old" value, even if it means executing a lazy callable upon attribute change.
parent_token	Usually references the MapperProperty, used as a key for the hasparent() function to identify an "owning" attribute. Allows multiple AttributeImpls to all match a single owner attribute.
load_on_unexpire	if False, don't include this attribute in a load-on-expired operation, i.e. the "expired_attribute_loader" process. The attribute can still be in the "expired" list and be considered to be "expired". Previously, this flag was called "expire_missing" and is only used by a deferred column attribute.
send_modified_events	if False, the InstanceState._modified_event method will have no effect; this means the attribute will never show up as changed in a history entry.

def _default_value(self, state, dict_):

overrides sqlalchemy.orm.attributes.AttributeImpl._default_value

Produce an empty collection for an un-initialized attribute

def _dispose_previous_collection(self, state, collection, adapter, fire_event):

Undocumented

def _initialize_collection(self, state):

Undocumented

def _invalidate_collection(self, collection):

Undocumented

def append(self, state, dict_, value, initiator, passive=PASSIVE_OFF):

overrides sqlalchemy.orm.attributes.AttributeImpl.append

Undocumented

def delete(self, state, dict_):

Undocumented

def fire_append_event(self, state, dict_, value, initiator):

Undocumented

def fire_append_wo_mutation_event(self, state, dict_, value, initiator):

Undocumented

def fire_pre_remove_event(self, state, dict_, initiator):

A special event used for pop() operations.

The "remove" event needs to have the item to be removed passed to it, which in the case of pop from a set, we don't have a way to access the item before the operation. the event is used for all pop() operations (even though set.pop is the one where it is really needed).

def fire_remove_event(self, state, dict_, value, initiator):

Undocumented

def get_all_pending(self, state, dict_, passive=PASSIVE_NO_INITIALIZE):

overrides sqlalchemy.orm.attributes.AttributeImpl.get_all_pending

Return a list of tuples of (state, obj) for all objects in this attribute's current state + history.

Only applies to object-based attributes.

This is an inlining of existing functionality which roughly corresponds to:

get_state_history(

state, key, passive=PASSIVE_NO_INITIALIZE).sum()

def get_collection(self, state, dict_, user_data=None, passive=PASSIVE_OFF):

Retrieve the CollectionAdapter associated with the given state.

if user_data is None, retrieves it from the state using normal "get()" rules, which will fire lazy callables or return the "empty" collection value.

def get_history(self, state, dict_, passive=PASSIVE_OFF):

overrides sqlalchemy.orm.attributes.AttributeImpl.get_history

Undocumented

def pop(self, state, dict_, value, initiator, passive=PASSIVE_OFF):

overrides sqlalchemy.orm.attributes.AttributeImpl.pop

Undocumented

def remove(self, state, dict_, value, initiator, passive=PASSIVE_OFF):

overrides sqlalchemy.orm.attributes.AttributeImpl.remove

Undocumented

def set(self, state, dict_, value, initiator=None, passive=PASSIVE_OFF, check_old=None, pop=False, _adapt=True):

overrides sqlalchemy.orm.attributes.AttributeImpl.set

Undocumented

def set_committed_value(self, state, dict_, value):

overrides sqlalchemy.orm.attributes.AttributeImpl.set_committed_value

Set an attribute value on the given instance and 'commit' it.

__slots__: tuple[str, ...] =

overrides sqlalchemy.orm.attributes.AttributeImpl.__slots__

Undocumented

collection: bool =

Undocumented

default_accepts_scalar_loader: bool =

Undocumented

dynamic: bool =

Undocumented

supports_population: bool =

Undocumented

uses_objects: bool =

Undocumented

_append_token =

Undocumented

_bulk_replace_token =

Undocumented

_duck_typed_as =

Undocumented

_remove_token =

Undocumented

collection_factory =

Undocumented

copy =

Undocumented