Container proxy implementation for Zope3
Project description
This package provides a proxy container implementation for Zope3.
z3c.proxy
We can proxy a regular container derived from zope’s btree container for example:
>>> from zope.container.interfaces import IContainer >>> from zope.container.btree import BTreeContainer >>> container = BTreeContainer() >>> container.__name__, container.__parent__ = u'c1', u'p1'>>> from z3c.proxy import interfaces >>> from z3c.proxy.container import LocationProxy >>> from z3c.proxy.container import ContainerLocationProxy >>> proxy = ContainerLocationProxy(container)
The name and the parent of the proxy is None. The proxy provides IContainer:
>>> proxy.__name__ is None True >>> proxy.__parent__ is None True >>> IContainer.providedBy(proxy) True >>> interfaces.IContainerLocationProxy.providedBy(proxy) True
First we check the empty proxy:
>>> proxy['x'] Traceback (most recent call last): ... KeyError: 'x'>>> 'x' in proxy False>>> proxy.has_key('x') 0>>> [key for key in proxy.keys()] []>>> [item for item in proxy.items()] []>>> proxy.get('x') is None True>>> iterator = iter(proxy) >>> iterator.next() Traceback (most recent call last): ... StopIteration>>> proxy.values() []>>> len(proxy) 0>>> del proxy['x'] Traceback (most recent call last): ... KeyError: 'x'>>> from zope.container.contained import Contained >>> proxy['x'] = x = Contained()
Now we added our first item. This item should be added to the container. Its name will be x and its parent is the container itself:
>>> x is container['x'] True>>> x.__name__ u'x'>>> x.__parent__ is container True
If we lookup ‘x’ within the proxy we do not get the blank ‘x’ but rather the proxied ‘x’. The proxy is not ‘x’ but only equal to ‘x’:
>>> x is proxy['x'] False>>> x == proxy['x'] True>>> x1 = proxy['x'] >>> from zope.proxy import isProxy >>> isProxy(x1) True>>> isinstance(x1, LocationProxy) True
The proxied ‘x’ has still the same name but not the same parent:
>>> x1.__name__ u'x'>>> x1.__parent__ is container False>>> x1.__parent__ is proxy True
If we add a second item to the container, it should appear in the proxy, too. But this item is proxied as container location proxy:
>>> container['y'] = y = BTreeContainer() >>> y1 = proxy['y'] >>> y1 is y False>>> y1 == y True>>> isinstance(y1, ContainerLocationProxy) True
The container location proxy is able to proxy the location of nested objects:
>>> proxy['y']['z'] = z = Contained() >>> container['y']['z'] is z True>>> z1 = y1['z'] >>> z1 is z False>>> z1 == z True>>> isinstance(z1, LocationProxy) True>>> z1.__parent__ is y1 True
Finaly we check all other methods of the proxy:
>>> 'x' in proxy True>>> proxy.has_key('x') 1>>> keys = [key for key in proxy.keys()]; keys.sort(); keys [u'x', u'y']>>> items = [item for item in proxy.items()]; items.sort() >>> items == [(u'x', x), (u'y', y)] True>>> proxy.get('x') == x True>>> iterator = iter(proxy) >>> iterator.next() in proxy True>>> iterator.next() in proxy True>>> iterator.next() Traceback (most recent call last): ... StopIteration>>> values = proxy.values(); values.sort(); >>> x in values, y in values (True, True)>>> len(proxy) 2>>> del proxy['x'] >>> 'x' in proxy False
ObjectMover
To use an object mover, pass a contained object to the class. The contained object should implement IContained. It should be contained in a container that has an adapter to INameChooser.
Setup test container and proxies:
>>> from zope.interface import implements >>> from zope.container.interfaces import INameChooser >>> from zope.copypastemove import ExampleContainer >>> from z3c.proxy.container import ProxyAwareObjectMover>>> class ContainerLocationProxyStub(ContainerLocationProxy): ... ... implements(INameChooser) ... ... def chooseName(self, name, ob): ... while name in self: ... name += '_' ... return name>>> container = ExampleContainer() >>> container2 = ExampleContainer()>>> ob = Contained() >>> proxy = ContainerLocationProxyStub(container) >>> proxy[u'foo'] = ob >>> ob = proxy[u'foo'] >>> mover = ProxyAwareObjectMover(ob)
In addition to moving objects, object movers can tell you if the object is movable:
>>> mover.moveable() 1
which, at least for now, they always are. A better question to ask is whether we can move to a particular container. Right now, we can always move to a container of the same class:
>>> proxy2 = ContainerLocationProxyStub(container2) >>> mover.moveableTo(proxy2) 1>>> mover.moveableTo({}) Traceback (most recent call last): ... TypeError: Container is not a valid Zope container.
Of course, once we’ve decided we can move an object, we can use the mover to do so:
>>> mover.moveTo(proxy2) u'foo'>>> list(proxy) []>>> list(proxy2) [u'foo']>>> ob = proxy2[u'foo'] >>> ob.__parent__ is proxy2 True
We can also specify a name:
>>> mover.moveTo(proxy2, u'bar') u'bar'>>> list(proxy2) [u'bar']>>> ob = proxy2[u'bar'] >>> ob.__parent__ is proxy2 True>>> ob.__name__ u'bar'
But we may not use the same name given, if the name is already in use:
>>> proxy2[u'splat'] = 1 >>> mover.moveTo(proxy2, u'splat') u'splat_'>>> l = list(proxy2) >>> l.sort() >>> l [u'splat', u'splat_']>>> ob = proxy2[u'splat_'] >>> ob.__name__ u'splat_'
If we try to move to an invalid container, we’ll get an error:
>>> mover.moveTo({})
Traceback (most recent call last):
...
TypeError: Container is not a valid Zope container.
ObjectCopier
To use an object copier, pass a contained object to the class. The contained object should implement IContained. It should be contained in a container that has an adapter to INameChooser.
Setup test container and proxies:
>>> from z3c.proxy.container import ProxyAwareObjectCopier >>> class ContainerLocationProxyStub(ContainerLocationProxy): ... ... implements(INameChooser) ... ... def chooseName(self, name, ob): ... while name in self: ... name += '_' ... return name>>> container = ExampleContainer() >>> container2 = ExampleContainer()>>> proxy = ContainerLocationProxyStub(container) >>> proxy[u'foo'] = ob = Contained() >>> ob = proxy[u'foo'] >>> copier = ProxyAwareObjectCopier(ob)
In addition to moving objects, object copiers can tell you if the object is movable:
>>> copier.copyable() 1
which, at least for now, they always are. A better question to ask is whether we can copy to a particular container. Right now, we can always copy to a container of the same class:
>>> proxy2 = ContainerLocationProxyStub(container2) >>> copier.copyableTo(proxy2) 1>>> copier.copyableTo({}) Traceback (most recent call last): ... TypeError: Container is not a valid Zope container.
Of course, once we’ve decided we can copy an object, we can use the copier to do so:
>>> copier.copyTo(proxy2) u'foo'>>> list(proxy) [u'foo']>>> list(proxy2) [u'foo']>>> ob.__parent__ is proxy 1>>> proxy2[u'foo'] is ob 0>>> proxy2[u'foo'].__parent__ is proxy2 1>>> proxy2[u'foo'].__name__ u'foo'
We can also specify a name:
>>> copier.copyTo(proxy2, u'bar') u'bar'>>> l = list(proxy2) >>> l.sort() >>> l [u'bar', u'foo']>>> ob.__parent__ is proxy 1>>> proxy2[u'bar'] is ob 0>>> proxy2[u'bar'].__parent__ is proxy2 1>>> proxy2[u'bar'].__name__ u'bar'
But we may not use the same name given, if the name is already in use:
>>> copier.copyTo(proxy2, u'bar') u'bar_'>>> l = list(proxy2) >>> l.sort() >>> l [u'bar', u'bar_', u'foo']>>> proxy2[u'bar_'].__name__ u'bar_'
If we try to copy to an invalid container, we’ll get an error:
>>> copier.copyTo({})
Traceback (most recent call last):
...
TypeError: Container is not a valid Zope container.
ProxyAwareContainerItemRenamer
This adapter uses IObjectMover to move an item within the same container to a different name. We need to first setup an adapter for IObjectMover:
Setup test container and proxies:
>>> from zope.container.sample import SampleContainer >>> from zope.copypastemove import ContainerItemRenamer >>> from zope.copypastemove import IObjectMover >>> from z3c.proxy.container import ProxyAwareContainerItemRenamer>>> import zope.component >>> from zope.container.interfaces import IContained >>> zope.component.provideAdapter(ProxyAwareObjectMover, [IContained], ... IObjectMover)>>> class ContainerLocationProxyStub(ContainerLocationProxy): ... ... implements(INameChooser) ... ... def chooseName(self, name, ob): ... while name in self: ... name += '_' ... return name
To rename an item in a container, instantiate a ContainerItemRenamer with the container:
>>> container = SampleContainer() >>> proxy = ContainerLocationProxyStub(container) >>> renamer = ProxyAwareContainerItemRenamer(container)
For this example, we’ll rename an item ‘foo’:
>>> from z3c.proxy.container import _unproxy >>> foo = Contained() >>> proxy['foo'] = foo >>> proxy['foo'] == _unproxy(foo) True
to ‘bar’:
>>> renamer.renameItem('foo', 'bar') >>> proxy['foo'] is foo Traceback (most recent call last): KeyError: 'foo'>>> proxy['bar'] == _unproxy(foo) True
If the item being renamed isn’t in the container, a NotFoundError is raised:
>>> renamer.renameItem('foo', 'bar') # doctest:+ELLIPSIS
Traceback (most recent call last):
ItemNotFoundError: (<...SampleContainer...>, 'foo')
If the new item name already exists, a DuplicationError is raised:
>>> renamer.renameItem('bar', 'bar')
Traceback (most recent call last):
DuplicationError: bar is already in use
CHANGES
0.6.1 (2010-08-23)
Added doctest to long_description to render on PyPI.
0.6.0 (2010-08-23)
Replaced zope.app.container by zope.container.
Using Python’s doctest module instead of deprecated zope.testing.doctestunit.
0.5.0 (2008-04-12)
Initial Release
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
