class Mutable(MutableBase): (source)
Known subclasses: sqlalchemy.ext.mutable.MutableDict, sqlalchemy.ext.mutable.MutableList, sqlalchemy.ext.mutable.MutableSet
Mixin that defines transparent propagation of change events to a parent object. See the example in :ref:`mutable_scalars` for usage information.
| Class Method | as |
Associate a SQL type with this mutable Python type. |
| Class Method | associate |
Associate this wrapper with all future mapped columns of the given type. |
| Class Method | associate |
Establish this type as a mutation listener for the given mapped descriptor. |
| Method | changed |
Subclasses should call this method whenever change events occur. |
Inherited from MutableBase:
| Class Method | coerce |
Given a value, coerce it into the target type. |
| Class Method | _get |
Given a descriptor attribute, return a ``set()`` of the attribute keys which indicate a change in the state of this attribute. |
| Class Method | _listen |
Establish this type as a mutation listener for the given mapped descriptor. |
| Property | _parents |
Dictionary of parent object's :class:`.InstanceState`->attribute name on the parent. |
Associate a SQL type with this mutable Python type. This establishes listeners that will detect ORM mappings against the given type, adding mutation event trackers to those mappings. The type is returned, unconditionally as an instance, so that :meth:`.as_mutable` can be used inline:: Table('mytable', metadata, Column('id', Integer, primary_key=True), Column('data', MyMutableType.as_mutable(PickleType)) ) Note that the returned type is always an instance, even if a class is given, and that only columns which are declared specifically with that type instance receive additional instrumentation. To associate a particular mutable type with all occurrences of a particular type, use the :meth:`.Mutable.associate_with` classmethod of the particular :class:`.Mutable` subclass to establish a global association. .. warning:: The listeners established by this method are *global* to all mappers, and are *not* garbage collected. Only use :meth:`.as_mutable` for types that are permanent to an application, not with ad-hoc types else this will cause unbounded growth in memory usage.
Associate this wrapper with all future mapped columns of the given type. This is a convenience method that calls ``associate_with_attribute`` automatically. .. warning:: The listeners established by this method are *global* to all mappers, and are *not* garbage collected. Only use :meth:`.associate_with` for types that are permanent to an application, not with ad-hoc types else this will cause unbounded growth in memory usage.