Metadata-Version: 1.1
Name: zope.site
Version: 3.6.1
Summary: Local registries for zope component architecture
Home-page: http://pypi.python.org/pypi/zope.site
Author: Zope Corporation and Contributors
Author-email: zope-dev@zope.org
License: ZPL 2.1
Description: This package adds support for persistent local component registries for
        the zope component architecture.
        
        
        Detailed Documentation
        **********************
        
        
        =====================================
        Zope 3's Local Component Architecture
        =====================================
        
        This package provides a local and persistent site manager
        implementation, so that one can register local utilities and
        adapters. It uses local adapter registries for its adapter and utility
        registry. The module also provides some facilities to organize the
        local software and ensures the correct behavior inside the ZODB.
        
        Local Component Architecture API
        --------------------------------
        
        While the component architecture API provided by ``zope.component`` is
        sufficient most of the time, there are a couple of functions that are
        useful in the context of multiple sites and base component registries.
        
        It is common for a utility to delegate its answer to a utility
        providing the same interface in one of the component registry's
        bases. Let's first create a global utility::
        
          >>> import zope.interface
          >>> class IMyUtility(zope.interface.Interface):
          ...     pass
        
          >>> class MyUtility(object):
          ...     zope.interface.implements(IMyUtility)
          ...     def __init__(self, id):
          ...         self.id = id
          ...     def __repr__(self):
          ...         return "%s('%s')" % (self.__class__.__name__, self.id)
        
          >>> gutil = MyUtility('global')
          >>> from zope.component import getGlobalSiteManager
          >>> gsm = getGlobalSiteManager()
          >>> gsm.registerUtility(gutil, IMyUtility, 'myutil')
        
        We create a simple folder hierarchy we can place our utilities in:
        
          >>> from zope.site.folder import Folder, rootFolder
          >>> root = rootFolder()
          >>> root[u'folder1'] = Folder()
          >>> root[u'folder1'][u'folder1_1'] = Folder()
        
        We set up site managers in the folders::
        
          >>> from zope.site import testing
          >>> root_sm = testing.createSiteManager(root)
          >>> folder1_sm = testing.createSiteManager(root['folder1'])
          >>> folder1_1_sm = testing.createSiteManager(root['folder1']['folder1_1'])
        
        Now we create two utilities and insert them in our folder hierarchy:
        
          >>> util1 = testing.addUtility(folder1_sm, 'myutil', IMyUtility,
          ...                            MyUtility('one'))
          >>> util1_1 = testing.addUtility(folder1_1_sm, 'myutil', IMyUtility,
          ...                              MyUtility('one-one'))
        
        Now, if we ask `util1_1` for its next available utility we get the
        ``one`` utility::
        
          >>> from zope import site
          >>> site.getNextUtility(util1_1, IMyUtility, 'myutil')
          MyUtility('one')
        
        Next we ask `util1` for its next utility and we should get the global version:
        
          >>> site.getNextUtility(util1, IMyUtility, 'myutil')
          MyUtility('global')
        
        However, if we ask the global utility for the next one, an error is raised
        
          >>> site.getNextUtility(gutil, IMyUtility,
          ...                     'myutil') #doctest: +NORMALIZE_WHITESPACE
          Traceback (most recent call last):
          ...
          ComponentLookupError:
          No more utilities for <InterfaceClass __builtin__.IMyUtility>,
          'myutil' have been found.
        
        You can also use `queryNextUtility` and specify a default:
        
          >>> site.queryNextUtility(gutil, IMyUtility, 'myutil', 'default')
          'default'
        
        Let's now ensure that the function also works with multiple registries. First
        we create another base registry:
        
          >>> from zope.component import registry
          >>> myregistry = registry.Components()
        
        We now set up another utility into that registry:
        
          >>> custom_util = MyUtility('my_custom_util')
          >>> myregistry.registerUtility(custom_util, IMyUtility, 'my_custom_util')
        
        We add it as a base to the local site manager:
        
          >>> folder1_sm.__bases__ = (myregistry,) + folder1_sm.__bases__
        
        Both the ``myregistry`` and global utilities should be available:
        
          >>> site.queryNextUtility(folder1_sm, IMyUtility, 'my_custom_util')
          MyUtility('my_custom_util')
          >>> site.queryNextUtility(folder1_sm, IMyUtility, 'myutil')
          MyUtility('global')
        
        
        =============================
        Sites and Local Site Managers
        =============================
        
        This is an introduction of location-based component architecture.
        
        Creating and Accessing Sites
        ----------------------------
        
        *Sites* are used to provide custom component setups for parts of your
        application or web site. Every folder:
        
          >>> from zope.site import folder
          >>> myfolder = folder.rootFolder()
        
        has the potential to become a site:
        
          >>> from zope.location.interfaces import ISite, IPossibleSite
          >>> IPossibleSite.providedBy(myfolder)
          True
        
        but is not yet one:
        
          >>> ISite.providedBy(myfolder)
          False
        
        If you would like your custom content component to be able to become a site,
        you can use the `SiteManagerContainer` mix-in class:
        
          >>> from zope import site
          >>> class MyContentComponent(site.SiteManagerContainer):
          ...     pass
        
          >>> myContent = MyContentComponent()
          >>> IPossibleSite.providedBy(myContent)
          True
          >>> ISite.providedBy(myContent)
          False
        
        To convert a possible site to a real site, we have to provide a site manager:
        
          >>> sm = site.LocalSiteManager(myfolder)
          >>> myfolder.setSiteManager(sm)
          >>> ISite.providedBy(myfolder)
          True
          >>> myfolder.getSiteManager() is sm
          True
        
        Note that an event is generated when a local site manager is created:
        
          >>> from zope.component.eventtesting import getEvents
          >>> from zope.site.interfaces import INewLocalSite
          >>> [event] = getEvents(INewLocalSite)
          >>> event.manager is sm
          True
        
        If one tries to set a bogus site manager, a `ValueError` will be raised:
        
           >>> myfolder2 = folder.Folder()
           >>> myfolder2.setSiteManager(object)
           Traceback (most recent call last):
           ...
           ValueError: setSiteManager requires an IComponentLookup
        
        If the possible site has been changed to a site already, a `TypeError`
        is raised when one attempts to add a new site manager:
        
          >>> myfolder.setSiteManager(site.LocalSiteManager(myfolder))
          Traceback (most recent call last):
          ...
          TypeError: Already a site
        
        There is also an adapter you can use to get the next site manager from any
        location:
        
          >>> myfolder['mysubfolder'] = folder.Folder()
          >>> import zope.component
          >>> zope.component.interfaces.IComponentLookup(myfolder['mysubfolder']) is sm
          True
        
        If the location passed is a site, the site manager of that site is returned:
        
          >>> zope.component.interfaces.IComponentLookup(myfolder) is sm
          True
        
        During traversal,
        
          >>> from zope.app import publication
          >>> request = object()
          >>> ev = publication.interfaces.BeforeTraverseEvent(myfolder, request)
          >>> site.threadSiteSubscriber(myfolder, ev)
        
        the nearest site is also recorded in a thread-global variable:
        
          >>> from zope.site import hooks
          >>> hooks.getSite() is myfolder
          True
        
        After a request is completed, the site setting is cleared again:
        
          >>> ev = publication.interfaces.EndRequestEvent(myfolder, request)
          >>> site.clearThreadSiteSubscriber(ev)
          >>> hooks.getSite() is None
          True
        
        
        Using the Site Manager
        ----------------------
        
        A site manager contains several *site management folders*, which are used to
        logically organize the software. When a site manager is initialized, a default
        site management folder is created:
        
          >>> sm = myfolder.getSiteManager()
          >>> default = sm['default']
          >>> default.__class__
          <class 'zope.site.site.SiteManagementFolder'>
        
        However, you can tell not to create the default site manager folder on
        LocalSiteManager creation:
        
          >>> nodefault = site.LocalSiteManager(myfolder, default_folder=False)
          >>> 'default' in nodefault
          False
        
        You can easily create a new site management folder:
        
          >>> sm['mySMF'] = site.SiteManagementFolder()
          >>> sm['mySMF'].__class__
          <class 'zope.site.site.SiteManagementFolder'>
        
        Once you have your site management folder -- let's use the default one -- we
        can register some components. Let's start with a utility:
        
          >>> import zope.interface
          >>> class IMyUtility(zope.interface.Interface):
          ...     pass
        
          >>> import persistent
          >>> from zope.container.contained import Contained
          >>> class MyUtility(persistent.Persistent, Contained):
          ...     zope.interface.implements(IMyUtility)
          ...     def __init__(self, title):
          ...         self.title = title
          ...     def __repr__(self):
          ...         return "%s('%s')" %(self.__class__.__name__, self.title)
        
        Now we can create an instance of our utility and put it in the site
        management folder and register it:
        
          >>> myutil = MyUtility('My custom utility')
          >>> default['myutil'] = myutil
          >>> sm.registerUtility(myutil, IMyUtility, 'u1')
        
        Now we can ask the site manager for the utility:
        
          >>> sm.queryUtility(IMyUtility, 'u1')
          MyUtility('My custom utility')
        
        Of course, the local site manager has also access to the global component
        registrations:
        
          >>> gutil = MyUtility('Global Utility')
          >>> from zope.component import getGlobalSiteManager
          >>> gsm = getGlobalSiteManager()
          >>> gsm.registerUtility(gutil, IMyUtility, 'gutil')
        
          >>> sm.queryUtility(IMyUtility, 'gutil')
          MyUtility('Global Utility')
        
        Next let's see whether we can also successfully register an adapter as
        well. Here the adapter will provide the size of a file:
        
          >>> class IFile(zope.interface.Interface):
          ...     pass
        
          >>> class ISized(zope.interface.Interface):
          ...     pass
        
          >>> class File(object):
          ...     zope.interface.implements(IFile)
        
          >>> class FileSize(object):
          ...     zope.interface.implements(ISized)
          ...     def __init__(self, context):
          ...         self.context = context
        
        Now that we have the adapter we need to register it:
        
          >>> sm.registerAdapter(FileSize, [IFile])
        
        Finally, we can get the adapter for a file:
        
          >>> file = File()
          >>> size = sm.queryAdapter(file, ISized, name='')
          >>> size.__class__
          <class 'FileSize'>
          >>> size.context is file
          True
        
        By the way, once you set a site
        
          >>> hooks.setSite(myfolder)
        
        you can simply use the zope.component's `getSiteManager()` method to get
        the nearest site manager:
        
          >>> from zope.component import getSiteManager
          >>> getSiteManager() is sm
          True
        
        This also means that you can simply use zope.component to look up your utility
        
          >>> from zope.component import getUtility
          >>> getUtility(IMyUtility, 'gutil')
          MyUtility('Global Utility')
        
        or the adapter via the interface's `__call__` method:
        
          >>> size = ISized(file)
          >>> size.__class__
          <class 'FileSize'>
          >>> size.context is file
          True
        
        
        Multiple Sites
        --------------
        
        Until now we have only dealt with one local and the global site. But things
        really become interesting, once we have multiple sites. We can override other
        local configuration.
        
        Let's now create a new folder called `folder11`, add it to `myfolder` and make
        it a site:
        
          >>> myfolder11 = folder.Folder()
          >>> myfolder['myfolder11'] = myfolder11
          >>> myfolder11.setSiteManager(site.LocalSiteManager(myfolder11))
          >>> sm11 = myfolder11.getSiteManager()
        
        If we ask the second site manager for its next, we get
        
          >>> sm11.__bases__ == (sm, )
          True
        
        and the first site manager should have the folling sub manager:
        
          >>> sm.subs == (sm11,)
          True
        
        If we now register a second utility with the same name and interface with the
        new site manager folder,
        
          >>> default11 = sm11['default']
          >>> myutil11 = MyUtility('Utility, uno & uno')
          >>> default11['myutil'] = myutil11
        
          >>> sm11.registerUtility(myutil11, IMyUtility, 'u1')
        
        then it will will be available in the second site manager
        
          >>> sm11.queryUtility(IMyUtility, 'u1')
          MyUtility('Utility, uno & uno')
        
        but not in the first one:
        
          >>> sm.queryUtility(IMyUtility, 'u1')
          MyUtility('My custom utility')
        
        It is also interesting to look at the use cases of moving and copying a
        site. To do that we create a second root folder and make it a site, so that
        site hierarchy is as follows:
        
        ::
        
                   _____ global site _____
                  /                       \
              myfolder1                myfolder2
                  |
              myfolder11
        
        
          >>> myfolder2 = folder.rootFolder()
          >>> myfolder2.setSiteManager(site.LocalSiteManager(myfolder2))
        
        Before we can move or copy sites, we need to register two event subscribers
        that manage the wiring of site managers after moving or copying:
        
          >>> from zope import container
          >>> gsm.registerHandler(
          ...    site.changeSiteConfigurationAfterMove,
          ...    (ISite, container.interfaces.IObjectMovedEvent),
          ...    )
        
        We only have to register one event listener, since the copy action causes an
        `IObjectAddedEvent` to be created, which is just a special type of
        `IObjectMovedEvent`.
        
        First, make sure that everything is setup correctly in the first place:
        
          >>> myfolder11.getSiteManager().__bases__ == (myfolder.getSiteManager(), )
          True
          >>> myfolder.getSiteManager().subs[0] is myfolder11.getSiteManager()
          True
          >>> myfolder2.getSiteManager().subs
          ()
        
        Let's now move `myfolder11` from `myfolder` to `myfolder2`:
        
          >>> myfolder2['myfolder21'] = myfolder11
          >>> del myfolder['myfolder11']
        
        Now the next site manager for `myfolder11`'s site manager should have changed:
        
          >>> myfolder21 = myfolder11
          >>> myfolder21.getSiteManager().__bases__ == (myfolder2.getSiteManager(), )
          True
          >>> myfolder2.getSiteManager().subs[0] is myfolder21.getSiteManager()
          True
          >>> myfolder.getSiteManager().subs
          ()
        
        Now, we make a copy of `myfolder21` and add it as `myfolder11` to
        `myfolder`:
        
          # Make sure that our interfaces and classes are picklable.
        
          >>> import sys
          >>> sys.modules['zope.site.tests'].IMyUtility = IMyUtility
          >>> IMyUtility.__module__ = 'zope.site.tests'
          >>> sys.modules['zope.site.tests'].MyUtility = MyUtility
          >>> MyUtility.__module__ = 'zope.site.tests'
        
          >>> from zope.copy import copy
          >>> myfolder['myfolder11'] = copy(myfolder2['myfolder21'])
        
          >>> myfolder11 = myfolder['myfolder11']
          >>> myfolder11.getSiteManager().__bases__ == (myfolder.getSiteManager(), )
          True
          >>> myfolder.getSiteManager().subs[0] is myfolder11.getSiteManager()
          True
          >>> myfolder2.getSiteManager().subs[0] is myfolder21.getSiteManager()
          True
        
        Finally, let's check that everything works fine when our folder is moved
        to the folder that doesn't contain any site manager. Our folder's
        sitemanager's bases should be set to global site manager.
        
          >>> myfolder11.getSiteManager().__bases__ == (myfolder.getSiteManager(), )
          True
        
          >>> nosm = folder.Folder()
          >>> nosm['root'] = myfolder11
          >>> myfolder11.getSiteManager().__bases__ == (gsm, )
          True
        
        
        =======
        CHANGES
        =======
        
        3.6.1 (2009-02-28)
        ------------------
        
        - Import symbols moved from zope.traversing to zope.location from the new
          location.
        
        - Don't fail when changing component registry bases while moving ISite
          object to non-ISite object.
        
        - Allow specify whether to create 'default' SiteManagementFolder on
          initializing LocalSiteManager. Use the ``default_folder`` argument.
        
        - Add a containment constraint to the SiteManagementFolder that makes
          it only available to be contained in ILocalSiteManagers and other
          ISiteManagementFolders.
        
        - Change package's mailing list address to zope-dev at zope.org, as
          zope3-dev at zope.org is now retired.
        
        - Remove old unused code. Update package description.
        
        3.6.0 (2009-01-31)
        ------------------
        
        - Use zope.container instead of zope.app.container.
        
        3.5.1 (2009-01-27)
        ------------------
        
        - Extracted from zope.app.component (trunk, 3.5.1 under development)
          as part of an effort to clean up dependencies between Zope packages.
        
Keywords: zope component architecture local
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Zope Public License
Classifier: Programming Language :: Python
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Topic :: Internet :: WWW/HTTP
Classifier: Framework :: Zope3
