diff options
Diffstat (limited to 'lib/sqlalchemy/ext/mutable.py')
| -rw-r--r-- | lib/sqlalchemy/ext/mutable.py | 243 |
1 files changed, 241 insertions, 2 deletions
diff --git a/lib/sqlalchemy/ext/mutable.py b/lib/sqlalchemy/ext/mutable.py index e49e9ea8b..571bbbda3 100644 --- a/lib/sqlalchemy/ext/mutable.py +++ b/lib/sqlalchemy/ext/mutable.py @@ -1,5 +1,5 @@ # ext/mutable.py -# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors +# Copyright (C) 2005-2016 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under @@ -403,6 +403,27 @@ class MutableBase(object): raise ValueError(msg % (key, type(value))) @classmethod + def _get_listen_keys(cls, attribute): + """Given a descriptor attribute, return a ``set()`` of the attribute + keys which indicate a change in the state of this attribute. + + This is normally just ``set([attribute.key])``, but can be overridden + to provide for additional keys. E.g. a :class:`.MutableComposite` + augments this set with the attribute keys associated with the columns + that comprise the composite value. + + This collection is consulted in the case of intercepting the + :meth:`.InstanceEvents.refresh` and + :meth:`.InstanceEvents.refresh_flush` events, which pass along a list + of attribute names that have been refreshed; the list is compared + against this set to determine if action needs to be taken. + + .. versionadded:: 1.0.5 + + """ + return set([attribute.key]) + + @classmethod def _listen_on_attribute(cls, attribute, coerce, parent_cls): """Establish this type as a mutation listener for the given mapped descriptor. @@ -415,6 +436,8 @@ class MutableBase(object): # rely on "propagate" here parent_cls = attribute.class_ + listen_keys = cls._get_listen_keys(attribute) + def load(state, *args): """Listen for objects loaded or refreshed. @@ -429,6 +452,10 @@ class MutableBase(object): state.dict[key] = val val._parents[state.obj()] = key + def load_attrs(state, ctx, attrs): + if not attrs or listen_keys.intersection(attrs): + load(state) + def set(target, value, oldvalue, initiator): """Listen for set/replace events on the target data member. @@ -463,7 +490,9 @@ class MutableBase(object): event.listen(parent_cls, 'load', load, raw=True, propagate=True) - event.listen(parent_cls, 'refresh', load, + event.listen(parent_cls, 'refresh', load_attrs, + raw=True, propagate=True) + event.listen(parent_cls, 'refresh_flush', load_attrs, raw=True, propagate=True) event.listen(attribute, 'set', set, raw=True, retval=True, propagate=True) @@ -574,6 +603,10 @@ class MutableComposite(MutableBase): """ + @classmethod + def _get_listen_keys(cls, attribute): + return set([attribute.key]).union(attribute.property._attribute_keys) + def changed(self): """Subclasses should call this method whenever change events occur.""" @@ -602,8 +635,26 @@ _setup_composite_listener() class MutableDict(Mutable, dict): """A dictionary type that implements :class:`.Mutable`. + The :class:`.MutableDict` object implements a dictionary that will + emit change events to the underlying mapping when the contents of + the dictionary are altered, including when values are added or removed. + + Note that :class:`.MutableDict` does **not** apply mutable tracking to the + *values themselves* inside the dictionary. Therefore it is not a sufficient + solution for the use case of tracking deep changes to a *recursive* + dictionary structure, such as a JSON structure. To support this use case, + build a subclass of :class:`.MutableDict` that provides appropriate + coersion to the values placed in the dictionary so that they too are + "mutable", and emit events up to their parent structure. + .. versionadded:: 0.8 + .. seealso:: + + :class:`.MutableList` + + :class:`.MutableSet` + """ def __setitem__(self, key, value): @@ -625,6 +676,16 @@ class MutableDict(Mutable, dict): dict.update(self, *a, **kw) self.changed() + def pop(self, *arg): + result = dict.pop(self, *arg) + self.changed() + return result + + def popitem(self): + result = dict.popitem(self) + self.changed() + return result + def clear(self): dict.clear(self) self.changed() @@ -644,3 +705,181 @@ class MutableDict(Mutable, dict): def __setstate__(self, state): self.update(state) + + +class MutableList(Mutable, list): + """A list type that implements :class:`.Mutable`. + + The :class:`.MutableList` object implements a list that will + emit change events to the underlying mapping when the contents of + the list are altered, including when values are added or removed. + + Note that :class:`.MutableList` does **not** apply mutable tracking to the + *values themselves* inside the list. Therefore it is not a sufficient + solution for the use case of tracking deep changes to a *recursive* + mutable structure, such as a JSON structure. To support this use case, + build a subclass of :class:`.MutableList` that provides appropriate + coersion to the values placed in the dictionary so that they too are + "mutable", and emit events up to their parent structure. + + .. versionadded:: 1.1 + + .. seealso:: + + :class:`.MutableDict` + + :class:`.MutableSet` + + """ + + def __setitem__(self, index, value): + """Detect list set events and emit change events.""" + list.__setitem__(self, index, value) + self.changed() + + def __setslice__(self, start, end, value): + """Detect list set events and emit change events.""" + list.__setslice__(self, start, end, value) + self.changed() + + def __delitem__(self, index): + """Detect list del events and emit change events.""" + list.__delitem__(self, index) + self.changed() + + def __delslice__(self, start, end): + """Detect list del events and emit change events.""" + list.__delslice__(self, start, end) + self.changed() + + def pop(self, *arg): + result = list.pop(self, *arg) + self.changed() + return result + + def append(self, x): + list.append(self, x) + self.changed() + + def extend(self, x): + list.extend(self, x) + self.changed() + + def insert(self, i, x): + list.insert(self, i, x) + self.changed() + + def remove(self, i): + list.remove(self, i) + self.changed() + + def clear(self): + list.clear(self) + self.changed() + + def sort(self): + list.sort(self) + self.changed() + + def reverse(self): + list.reverse(self) + self.changed() + + @classmethod + def coerce(cls, index, value): + """Convert plain list to instance of this class.""" + if not isinstance(value, cls): + if isinstance(value, list): + return cls(value) + return Mutable.coerce(index, value) + else: + return value + + def __getstate__(self): + return list(self) + + def __setstate__(self, state): + self[:] = state + + +class MutableSet(Mutable, set): + """A set type that implements :class:`.Mutable`. + + The :class:`.MutableSet` object implements a set that will + emit change events to the underlying mapping when the contents of + the set are altered, including when values are added or removed. + + Note that :class:`.MutableSet` does **not** apply mutable tracking to the + *values themselves* inside the set. Therefore it is not a sufficient + solution for the use case of tracking deep changes to a *recursive* + mutable structure. To support this use case, + build a subclass of :class:`.MutableSet` that provides appropriate + coersion to the values placed in the dictionary so that they too are + "mutable", and emit events up to their parent structure. + + .. versionadded:: 1.1 + + .. seealso:: + + :class:`.MutableDict` + + :class:`.MutableList` + + + """ + + def update(self, *arg): + set.update(self, *arg) + self.changed() + + def intersection_update(self, *arg): + set.intersection_update(self, *arg) + self.changed() + + def difference_update(self, *arg): + set.difference_update(self, *arg) + self.changed() + + def symmetric_difference_update(self, *arg): + set.symmetric_difference_update(self, *arg) + self.changed() + + def add(self, elem): + set.add(self, elem) + self.changed() + + def remove(self, elem): + set.remove(self, elem) + self.changed() + + def discard(self, elem): + set.discard(self, elem) + self.changed() + + def pop(self, *arg): + result = set.pop(self, *arg) + self.changed() + return result + + def clear(self): + set.clear(self) + self.changed() + + @classmethod + def coerce(cls, index, value): + """Convert plain set to instance of this class.""" + if not isinstance(value, cls): + if isinstance(value, set): + return cls(value) + return Mutable.coerce(index, value) + else: + return value + + def __getstate__(self): + return set(self) + + def __setstate__(self, state): + self.update(state) + + def __reduce_ex__(self, proto): + return (self.__class__, (list(self), )) |