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version 1123, Sun May 18 16:20:35 2003 UTC version 1997, Sun Jan 30 18:51:56 2005 UTC
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 Fixes and Enhancements since Version 0.5 alpha 1  Fixes and Enhancements since Version 0.5 alpha 3
   
  Changed, Enhanced, or Newly Deprecated Features   - PEAK no longer supports Python 2.2; Python 2.3.4 or better is required.
   
  - Standardized file-based URL syntaxes (e.g logfiles and lockfiles) to   - The kjbuckets extension module is no longer built and installed by default;
    follow RFC 1738/2396, and Python 'urllib'.  This shouldn't affect much     you must explicitly enable it with a '--with-kjbuckets' flag passed to
    besides the canonical forms of the URLs.  Added 'pkgfile:some.pkg/filepath'     'setup.py'.  Please port your code as soon as practical, this option will
    URL syntax for ease of referring to files near modules.  (A convenience     go away soon.
    intended mainly for referencing ZConfig schemas.)  
    - Use of the included 'kjbuckets' module is now DEPRECATED, due to increasing
  - Added the UML 1.4 metamodel, and thus the ability to load UML 1.4     bitrot.  Aaron Watters originally wrote this extension for Python 1.2, and
    models encoded in XMI 1.1.     it has not been well-maintained for newer versions of the Python/C API.
      Instead of 'kjSet' objects, use the Python 2.3 'Set' type, and instead of
  - Added support in the mof2py code generator for "unprefixing" enumerated     the 'kjGraph' type, use the new 'Graph' type in 'peak.util.Graph'.  Some
    values, so that UML and other metamodels' enumerations work correctly     porting effort may be required, as these types are not precisely the same
    when loading from XMI.     in signature as the originals.
   
  - 'binding.Acquire()' now accepts a 'default' value argument, and   - The '_setNS()' method of the 'peak.util.SOX.ISOXNode_NS' interface has
    'binding.New()' no longer accepts the 'bindToOwner' flag.     changed signature, due to a lack of use of the second argument in the code
      base, and its dependency on 'kjbuckets'.
  - There is a new 'binding.IComponentKey' interface that is used to implement  
    'IComponent.lookupComponent()'.  Now you can implement this interface,   - The old 'peak.security' implementation has been removed, and replaced with
    or create an adapter for it, in order to make an object usable as an     a simpler, more flexible implementation based on generic functions (using
    argument to 'binding.lookupComponent()' - and therefore usable as a key     less than half the code and seven fewer interfaces).  Complete documentation
    for 'binding.bindTo()' or 'binding.bindToSequence()'.  Not that it's     and API tests for the new implementation can be found in 'rules.txt' in the
    necessarily very useful to do so; you're probably better off simply     'peak.security' package directory.
    creating a naming scheme.  But it might be useful for lookups done  
    in the context of classes, since naming schemes aren't usable there.     Also, the new implemetation does not require redundant
    (It was actually added in order to factor out all the type testing that     'security.allow(security.Anybody)' declarations just because you've declared
    'lookupComponent' used to do, so it doesn't matter if it's useful for     other permissions for a class, so these declarations have been removed from
    much else.)     ``peak.web``.  They don't do any harm, however, so you can leave them in
      your own code as long as you change them to use 'binding.metadata()' instead
  - PEAK has been refactored to avoid the use of 'isImplementedBy()' and     of the deprecated 'security.allow()'.
    similar introspection, in favor of 'adapt()'.  As a result, some  
    'peak.naming' interfaces have changed.  This should not affect you   - 'security.allow()' is now DEPRECATED; please use 'binding.metadata()'
    if you are only subclassing PEAK-provided naming components and not     instead.  (There is no change to the calling signature, but
    implementing these interfaces "from scratch".  However, the various     'binding.metadata' accepts any metadata, not just permissions.)
    'isAddress', 'isAddressClass', 'isResolver', and 'isName' APIs have  
    also been removed, as they were based on 'isImplementedBy()'.   - Added 'peak.running.options', a new option-parsing framework that extends
      'optparse' to support the PEAK 'commands' framework.  Command instances
  - REMOVED ability to use '__implements__' and '__class_implements__' to     can now refer to 'self.parsed_args' to find their non-option arguments,
    declare support for interfaces.  Use 'protocols.advise()' or a related     and to trigger setting of their attributes (or calling of methods) based on
    API to do this now.  The 'protocols' package is available automatically     their raw arguments from 'self.argv'.  See 'options.txt' in the
    from 'peak.api'.     'peak.running' package directory for a complete tutorial.
   
    Similarly, the ability  to use 'isImplementedBy()' with interfaces declared   - There is now a 'binding.initAttrs()' function that can be used to initialize
    by PEAK is REMOVED.  You can still use 'isImplementedBy()' with Zope     an object's attributes from e.g. constructor keyword arguments, similar to
    interfaces, of course, but we recommend you switch to 'adapt()', which     how 'binding.Component' and 'binding.Attribute' constructors work.
    should work with both PEAK and Zope interfaces.  
    - Security permissions can now be declared as attribute metadata.
  - Replaced all use of 'zope.interface' with 'protocols' package because  
    the 'protocols' package:     That is, instead of doing declarations like this::
   
    * is considerably smaller and simpler than 'zope.interface'          class Foo:
               bar = binding.Require("Something", permissionNeeded=SomePerm)
    * produces Interface objects that can be inspected with the Python  
      'pydoc' and 'help()' tools          class AnElement(model.Element):
               class someFeature(model.Attribute):
    * supports and implements the PEP 246 'adapt()' protocol                  permissionNeeded = SomePerm
   
    * transparently supports transitive adaptation - i.e. if adapter AB     you can (and should) now do them like this::
      adapts from A to B, and adapter BC adapts from B to C, then an adapt(x,C)  
      where 'x' is an 'A', will be implemented as BC(AB(x)).          class Foo:
               bar = binding.Require("Something", [SomePerm])
    * Supports "open protocols" that allow you to "superclass" a protocol  
      to create a subset protocol; objects that support the first protocol          class AnElement(model.Element):
      will automatically support the subset protocol.  For example, if one              class someFeature(model.Attribute):
      person defines a "dictionary" protocol, someone else can create a                  metadata = [SomePerm]
      "read-only dictionary" protocol, and all objects supporting the  
      "dictionary protocol" will be considered to implement the "read-only     or this::
      dictionary" protocol.  
           class Foo:
    * can interoperate with other interface packages, including Zope's, but              binding.metadata(bar = [SomePerm])
      does not require them  
           class AnElement(model.Element):
    * works with module inheritance (for everything but moduleProvides(), and  
      we should get to that by 0.5a2)              binding.metadata(someFeature = [SomePerm])
   
    * lets you use Interfaces as abstract base classes (i.e., you can              class someFeature(model.Attribute):
      inherit from an interface and turn it into an implementation, and                  # ...
      you can define default attribute values or method implementations in  
      your interfaces     It isn't necessary to enclose metadata in brackets, but it helps to
      emphasize its annotational nature.  Also note that e.g. 'web.bindResource()'
    * Lets you mix interface declarations from any number of frameworks and     needs 'metadata' to be a keyword argument.
      any number of interface types, in a single 'implements()' or  
      'classProvides()'   - The 'permissionNeeded' attribute of 'model.Feature' and 'binding.Attribute'
      objects is now DEPRECATED.  See examples above for how to upgrade, and please
    * uses adaptation as the fundamental approach to dealing with interfaces,     switch to using metadata as soon as practical.  In addition the
      and avoids the use of 'isImplementedBy()'.  In the *rare* case that you     'security.IGuardedDescriptor' interface has been removed, because it was
      need to introspect rather than adapt, you can always call adapt() and     only used in connection with the 'permissionNeeded' attribute mechanism.
      check the result.  (But introspection usually means that you're using  
      interfaces as a form of metadata; it's better to create an explicit   - Added a new "attribute metadata" mini-framework to 'peak.binding'.  This
      interface that provides the metadata you seek, and adapt to that     framework makes it possible to declare arbitrary metadata about attributes,
      interface, than to use interfaces as data.)     using either a class advisor ('binding.metadata()', similar in form and
      function to the existing 'security.allow()') or using a 'metadata' attribute
    Most of these features are unavailable in 'zope.interface', and some have     of attribute bindings (which is the second positional parameter in all
    been declared by the Zope Pope to be unacceptable or undesirable features     the standard bindings like 'Make', 'Obtain', etc.).  Over time, existing
    for Zope interfaces.  (Others may be available in some form in future     metadata mechanisms will be refactored to use this new mini-framework,
    versions of Zope X3.)  So, we no longer require or distribute     instead of the various integrated ad-hoc mechanisms that exist now (like
    'zope.interface'.     the 'permissionNeeded' attribute).  For more information on how the new
      metadata hooks work, including doctest examples, see the 'attributes.txt'
  - The signatures of the 'getObjectInstance()', 'getStateToBind()', and     file in the 'peak.binding' package, under the heading "Attribute Metadata".
    'getURLContext()' methods in the 'peak.naming' package have changed, to  
    place the context or parent component as the first, non-optional argument.   - Added a new function, 'binding.activateClass()', that can be used to
    (If you don't know what these methods are for, you don't need to do anything     activate any bindings in the class.  This can now be used in place of
    about this, as they are part of the naming package's extensibility     subclassing a PEAK base class or using a PEAK metaclass.  In future, this
    framework.)     will be integrated into PEAK attribute descriptors such that defining a
      descriptor within a class' body is sufficient to cause this function to be
  - 'EigenRegistry' and 'PropertyMap' no longer attempt to figure out whether     invoked.
    implied (i.e. inherited) interfaces are more or less general with respect  
    to a previous registration.  This was behavior that emulated Zope adapter   - 'binding.IBindingNode' was REMOVED, consolidated into 'binding.IComponent',
    registries, but what we really wanted was more akin to a Zope "type"     as its various individual methods have been replaced with generic functions
    registry.  The only parts of the test suite that used the old behavior     in the existing 'binding' API.  For example, 'binding.getParentComponent(x)'
    were the tests specifically written to ensure that behavior!     should be used in preference to 'x.getParentComponent()' unless it is
      a requirement that 'x' implement the full 'binding.IComponent' interface.
  - 'binding.bindTo()' now accepts a 'default=' argument, whose value will be     This makes it easier to define what 'binding.getParentComponent()' and
    used in case of a 'NameNotFound' error.     'binding.getComponentName()' will mean for non-component types, as you do
      not have to define an adapter class with all of the 'IBindingNode' methods.
  - DEPRECATED 'naming.ParsedURL'.  It will disappear in 0.5 alpha 3 or beta.     Also, this makes PEAK itself cleaner, as we often weren't bothering to
    It is replaced by the new 'naming.URL.Base'.  The 'naming.URL' package     properly implement the full 'IBindingNode' interface anyway.
    provides a new URL parsing framework based on 'peak.model'.  Upgrading from  
    'ParsedURL' to 'URL.Base' is trivial for ParsedURL subclasses that used     In addition, 'binding.suggestParentComponent()' is now also a generic
    only the 'scheme' and 'body' fields, and in fact may not require any     function, dispatching on the target (i.e. child) object.
    changes except for the choice of base class.  Also, the 'retrieve()' method  
    of URLs is deprecated; please begin defining the 'getObjectInstance()'   - 'naming.IReferenceable' was REMOVED, as it is not in use anywhere in PEAK.
    method instead.  This is to cut down a bit on the number of ways that the     This will be replaced with a generic function when we do actually need this
    naming package spells the idea of retrieving something!     functionality.
   
    For more complex URL classes, the '__init__' methods go away, 'parse'   - There is a new 'config.getStreamFactory' generic function, to make it easy
    methods change slightly, and explicit field definitions (using     to accept URLs, filenames, or 'naming.IStreamFactory' objects as the source
    'model.structField' or similar) are required.  See PEAK's 'URL.Base'     of a "file".
    subclasses for examples.  There is also a sophisticated parsing and  
    formatting framework (see the 'peak.naming.URL' and 'peak.util.fmtparse'     Its typical usage is just::
    modules) that can be used in place of the old regex-based approach.  
          factory = config.getStreamFactory(self,source)
  - Added 'peak.util.fmtparse', a parsing and formatting framework, and         stream = factory.open('t')  # open for reading in text mode
    integrated it with 'peak.model' so that any element type can have a  
    syntax for parsing from, or formatting to, a string.     where 'source' is a string or a 'naming.IStreamFactory', and 'self' is a
      component to be used as lookup context.  The returned 'factory' is a
  - Added 'binding.whenAssembled(...)' as syntax sugar for     'naming.IStreamFactory' that can then be '.open()'-ed for reading, or used
    'binding.Once(...,activateUponAssembly=True)'.     in other ways as needed.
   
  - Removed 'LOG_XYZ' convenience functions from 'peak.api', and refactored     If you have special objects that you'd like to be able to treat as stream
    'peak.running.logs' to use a PEP 282-like interface, 'running.ILogger'.     sources, you can register them by defining an extension, e.g.::
    Under the new scheme, messages must be sent to a specific entry point  
    (e.g. 'self.logger.warning("foo")').  Components can bind an attribute      [config.getStreamFactory.when(MyType)]
    directly to a logger object, or via configuration properties or utilities.      def getStreamFactory(context,source):
    PEAK components that do logging all define a 'logger' attribute, bound          """Return a naming.IStreamFactory for 'source' (a 'MyType' instance)"""
    to a configuration property in the 'peak.logs' property namespace.  By  
    a default in 'peak.ini', 'peak.logs.*' is configured to output messages     Wherever practical, as we encounter them, we'll be changing PEAK API's that
    of 'WARNING' priority or higher to 'sys.stderr'.     take filenames to also accept stream sources.
   
    For compatibility with the PEP 282 logging package, a 'logging.logger:'   - Added an optional 'base' argument to 'naming.parseURL()', to allow parsing
    URL scheme has been added; looking up the URL '"logging.logger:foo.bar"'     URLs relative to a base URL.  For a URL scheme to support this, it must
    is equivalent to 'logging.getLogger("foo.bar")', unless the 'logging'     implement the new 'naming.IBaseURL' interface.  See the
    package is not available, in which case the configuration property     'peak.naming.factories.openable' module for example implementations.
    'peak.logs.foo.bar' will be looked up in the target context of the  
    lookup.  Optionally, you can configure the 'logging.logger' URL scheme so   - Added a 'data:' URL scheme, implementing RFC 2397 (although it's not as
    that it only uses PEAK loggers, and never uses the PEP 282 loggers.     strict in its parsing of the content type and parameters as the RFC calls
      for).  This is a semi-convenient way to provide configuration data in-line,
  - Added 'binding.metamethod()' wrapper for metaclass methods that might     since a 'data:' URL can be a 'config.getStreamFactory()' source.
    not be accessible from their instances if the instances (classes) also  
    defined the method for *their* instances.  You must now use this wrapper   - Added 'config.processXML()', a function that provides a high-level,
    on any such metaclass-defined methods, as PEAK no longer works around     configuration-driven interface to 'peak.util.SOX.NegotiatingParser'.  This
    this via the 'x.__class__.foo(x,...)' trick that was used previously.     simple front-end lets you supply as little as a configuration context and
    In particular, if you have metaclass definitions of 'getParentComponent',     a stream source, to do XML processing of arbitrary complexity, controlled by
    '_getConfigData', 'getComponentName', or 'notifyUponAssembly', you need     the configuration of the context.
    to wrap them with 'binding.metamethod' now.  
    - Added 'config.XMLKey()', an 'IConfigKey' type that can be used to register
  - Made 'NOT_GIVEN' and 'NOT_FOUND' recognizable by humans (they 'repr'     configuration values for XML attribute and element names under specified
    and 'str' to their names) and by Python (they can be pickled, and     XML namespace URI's.  Also, there are now '[XML Attributes for nsuri]' and
    when restored they come back as the same object).     '[XML Elements for nsuri]' section types available for use in .ini files.
      (Replace 'nsuri' with the appropriate XML namespace URI, or use '*' for a
      wildcard.)
  Corrected Problems  
    - 'web.IResource' is gone, replaced by 'web.IPlace'.  The notion of a place is
  - Fixed source distributions missing essential setup files     broader than the notion of a resource, and we will soon need to have
      other "location" objects that implement 'IPlace'.
  - Fixed a problem with assembly events, where a parent component that didn't  
    need assembly notification, wouldn't ever notify its children of assembly   - In order to support obtaining the line and column locations of problems in
    if they requested the notification after the parent had already received     XML files, we are now using Python 2.4's version of the 'pyexpat' module,
    it.     built as 'peak.util.pyexpat'.
   
  - Fixed 'naming.lookup()' and related APIs not setting the parent component   - There's a new class, 'config.IniLoader', that can be used to lazily load
    of created objects without an explicitly supplied 'creationParent' keyword     .ini files as configuration.  'IniLoader' instances have an 'iniFiles'
    argument.  This used to "sort of work" when we had implicit configuration     attribute that lists the configuration sources (filenames/URLs/factories)
    parents, but was broken when we went "all explicit" for 0.5 alpha 1.     to be used, and automatically load the .ini files as soon as you try to get
      any configuration data for them.  Previously, similar functionality was only
  - Fixed a problem where initializing single-valued immutable fields of     available via 'config.makeRoot()'.
   'peak.model' types did not perform type/value normalization.  
      Also, there's now an 'ini' reference type that instantiates an 'IniLoader'
  - Fixed a problem where bindTo would use the attribute name as the     for one or more addresses.  You can use it like this::
    default value for a lookup, if the requested name/property/utility  
    was not found.       [Named Services]
   
  - Fixed 'mof2py' generator script not working       some.example = naming.Reference('ini',
            ['pkgfile:peak/peak.ini', '/etc/something.ini']
         )
   
        another.example = naming.LinkRef(
            'ref:ini@pkgfile:peak/peak.ini||/etc/something.ini'
         )
   
      The two examples above will each load the same pair of specified .ini files.
      You can also directly instantiate an 'IniLoader', as in::
   
        cfg = config.IniLoader(self, iniFiles=['pkgfile:peak/peak.ini'])
   
      Attempting to look up any configuration properties via the 'cfg' object
      will cause it to load the specified .ini file.
   
    - 'config.fileNearModule()' is DEPRECATED, in favor of 'config.packageFile()'.
      The latter returns a 'naming.IStreamFactory', which is more suitable for
      working with e.g. module data files compressed in a zipfile.  Uses of
      'fileNearModule()' that were being passed to 'config.loadConfigFile()' can
      be safely changed to 'config.packageFile()' without needing any other code
      changes, but if you were directly using 'fileNearModule()' as a filename,
      you will need to rewrite appropriately.
   
    - 'config.loadConfigFile()' and 'config.loadConfigFiles()' now accept URLs,
      'naming.IStreamFactory' objects, and other 'config.getStreamFactory()'
      targets as well as filenames.  This was primarily added to support use of
      'config.packageFile()' or 'pkgfile:' URLs, in place of using
      'config.fileNearModule()'.
   
    - The 'naming.IStreamFactory' interface now has an 'address' attribute, which
      is the string form of the canonical URL of the target stream.  This was
      added to make it easier to e.g. report errors in a stream that's being
      parsed, since the parser only needs the factory in order to report the
      location of an error.  (Note: if you implement 'naming.IStreamFactory', be
      sure to add this attribute to your implementations.)
   
    - The 'peak.util.WSGIServer' module has been moved to the
      'wsgiref.simple_server' module.  The 'wsgiref' reference library for WSGI
      (aka PEP 333) is now distributed with PEAK.
   
    - Added a 'WSGI' command to the 'peak' script, to allow you to run "foreign"
      (i.e. non-PEAK) PEP 333 applications in PEAK's various servers and
      launchers.  Basically, by prefixing 'WSGI' before the import specifier, you
      can now run such foreign apps.
   
      For example::
   
          peak launch WSGI import:some_app.application
   
      will run 'some_app.application' in the local web browser, and::
   
          peak CGI WSGI import:some_app.application
   
      will run it under the CGI/FastCGI runner.  Similarly, you can use this in
      the "Command" spec for the "peak supervise" pre-forking FastCGI supervisor
      subsystem.
   
    - There is a new 'running.IWSGIApplication' interface, for PEP 333-compliant
      "application" objects, and all of PEAK's provided applications now implement
      it instead of 'running.IRerunnableCGI'.  If you write your apps to the newer
      interface, they'll be portable to any PEP 333-compliant web server, not just
      the PEAK CGI, FastCGI, and "supervisor" containers.  There is a simple
      adapter that allows 'IWSGIApplication' objects to run in the CGI-based
      containers, but not the other way around, so using 'IRerunnableCGI' directly
      now limits your portability.  (For example, the "peak launch" and "peak
      serve" commands will soon require 'IWSGIApplication', and will not support
      'IRerunnableCGI' any more.)
   
      Of course, if you use the 'peak.web' framework, you don't need to worry
      about any of this; your apps will automatically be wrapped as
      'IWSGIApplication', and run in any PEAK server or gateway.
   
    - Most 'peak.web' interfaces have changed significantly.  If you implemented
      anything based on the older interfaces, and it still works, it's sheer
      bloody luck.  In particular, note that every method in 'web.IWebTraversable'
      now has different inputs and/or outputs than before.  Please read the new
      interface docs and update your code!  The changed interfaces offer much
      more flexibility and functionality than before, but they will require you to
      update your code.
   
    - 'web.ContainerAsTraversable' has been removed.  It was redundant, since the
      new default traversal mechanism used by 'Traversable' and 'Decorator' now
      handles getitem, getattr, and views.
   
    - Added Zope 3-like "namespaces" to 'peak.web'.  Path segments in a URL
      may be prefixed with '"++some_id++"' in order to invoke a corresponding
      namespace handler registered under '"peak.web.namespaces.some_id"'.
      Namespace handlers must implement 'web.INamespaceHandler', and they are
      supplied with the original path segment as well as the separated namespace
      and name.  Also, as in Zope 3, '"@@foo"' is a shortcut for '"++view++foo"'.
      Builtin namespaces at this time include 'view', 'item', 'attr', 'skin', and
      'resources'.  'skin' treats the rest of its path segment as a skin name,
      and sets the current skin, while 'resources' begins traversal to resources
      found in the current skin.  The other namespaces are as described at:
   
      "Resources and traversal in peak.web":http://www.eby-sarna.com/pipermail/peak/2004-August/001712.html
   
    - Fixed several 'peak.events' bugs, as reported by Vladimir Iliev, Yaroslav
      Samchuk, and Alexander Smishlajev:
   
      * 'events.AnyOf' could hold multiple references to a single event source,
        and nesting 'AnyOf()' calls could leak references to the nested events.
   
      * 'events.subscribe()' had a potential race condition wherein a callback
        could be invoked after its weak reference was garbage collected, leading
        to bizarre error messages about 'self' being 'None'.
   
      * 'select()' could be called on select event objects even if there were
        no current subscribers to the event, potentially leading to calling
        'select()' on a closed socket.
   
      * Non-default signal handlers were remaining installed even when there
        were no current subscribers to the applicable event, as long as a
        reference to the event object existed.
   
      As a result of these changes, certain I/O event types (esp. signals and
      stream readable/writeable events) are now longer-lived.  For example,
      signal event objects are now immortal, and the read/write event for a
      particular 'fileno()' will be reused for as long as its supplying
      'Selector' or 'EventLoop' instance exists.  (Previously, weak references
      were used so that these objects would be recycled when not in use.)
   
    - Added 'config.registeredProtocol()' API, that supports defining named and
      local protocols.  This allows easy emulation of Zope 3's "named" and "local"
      adapters and views.
   
    - 'binding.Component' objects no longer support instance configuration at
      runtime (i.e., they no longer implement 'config.IConfigurable').  If you
      need a component to be configurable at runtime, you must now derive from
      (or mix in) 'binding.Configurable' instead.  If you get errors about
      a missing 'registerProvider' attribute, or about being unable to adapt to
      'IConfigurable', try changing your base class from 'binding.Component'
      to 'binding.Configurable', or add it as a mixin if you're deriving from
      a class that uses 'binding.Component' as its base.
   
    - 'binding.IComponent' no longer derives from 'config.IConfigurable' or
      'config.IConfigMap', only 'config.IConfigSource'.  This means that
      'IComponent' no longer guarantees or requires the presence of the
      'registerProvider()' method: now only 'config.IConfigurable' does that.
   
    - The 'config.IConfigMap' interface is now DEPRECATED.  Use
      'config.IConfigurable' instead.  The '_configKeysMatching()' method
      of 'IConfigMap' was moved to 'config.IConfigSource', so if you've
      implemented a custom 'IConfigSource', be sure to add this method.
   
    - 'web.ISkinService' and 'web.ILayerService' were consolidated into
      'web.IInteractionPolicy', because the need to have configurable
      implementations of these services is negligible.  That is, the
      corresponding property namespaces ('peak.web.skins' and 'peak.web.layers')
      are more than adequate as registries.
   
    - Removed 'peak.running.timers' and 'peak.util.dispatch'.  Neither was in
      active use, and both are being replaced by the new generic functions
      package in PyProtocols.
   
    - The 'config.iterParents' API is now moved to 'binding.iterParents', and all
      'binding' functions that walk the component hierarchy use it.  It has also
      been changed to avoid infinite loops in the case of a pathological
      component structure.
   
    - The 'persistence' package has been moved to 'peak.persistence' to avoid
      conflicts with ZODB3 and the latest version of Zope 3.  It will eventually
      be phased out, but for now this move is the simplest way to get it out of
      the way.
   
    - The 'peak.util.SOX' module now uses only one parser, based directly on
      'expat', instead of using SAX.  The new parser expects a new node interface,
      'IXMLBuilder', but adapters from the previous interfaces ('ISOXNode' and
      'ISOXNode_NS') are supplied for backward compatibility.  All of PEAK's
      direct XML handling (currently just 'peak.storage.xmi' and
      'peak.web.templates') have been refactored to use the new interface.  Some
      parsing classes (such as 'ObjectMakingHandler', 'NSHandler', and
      'DOMletParser') are no longer available.
   
    - 'peak.web' no longer uses Zope X3 for HTTP publishing support; it has been
      refactored to use a "simpler, more uniform architecture":http://www.eby-sarna.com/pipermail/peak/2004-May/001462.html
      See also "more on the architecture":http://www.eby-sarna.com/pipermail/peak/2004-June/001482.html
      and subsequent posts in that thread.
   
      As a consequence, "various features have been removed":http://www.eby-sarna.com/pipermail/peak/2004-June/001500.html
      from 'peak.web', for possible return at a future date.  Here is a rough
      outline of the changes made so far:
   
       * The 'pageProtocol', 'pathProtocol', and 'errorProtocol' machinery are
         gone.  They will be replaced in the future with an explicit "controller"
         wrapping mechanism to allow application-specific renderings of the same
         underlying components.
   
       * The Zope 'request' and 'response' objects are gone, along with all of
         their special handling for cookies, character sets, form variables,
         automatically marshalling parameters to functions, etc.  These items of
         functionality will be gradually replaced by functions in 'peak.web.api'.
   
         As a result of this, arbitrary functions and methods can no longer be
         used as web pages; instead, functions and methods to be published must
         use the same inputs and outputs as the 'IHTTPHandler.handle_http()'
         method.
   
       * The 'IWebPage', 'IWebInteraction', 'ITraversalContext', 'Traversal',
         'TraversalContext', and 'Interaction' interfaces and classes no longer
         exist, as they are unneeded in the new architecture.  Instead of
         having a central 'IWebInteraction' that's referenced by numerous
         'ITraversalContext' objects, the new approach uses an 'environ' mapping
         for most functions.  For access control, a 'security.IInteraction' is
         now used, whose function is limited to security checks.  Most
         functions previously performed by 'IWebInteraction' have moved to
         'IInteractionPolicy' or to 'peak.web.api' functions operating on
         'environ' mappings.
   
       * Web exceptions can define a 'levelName' attribute that determines the
         severity level with which the exception will be logged.  This allows
         one to e.g. avoid logging tracebacks for 'NotFound' errors.
   
       * Various interface calling signatures have changed slightly.  For example,
         'IAuthService.getUser()' now accepts an 'environ' mapping instead of
         an interaction.  'IInteractionPolicy.newInteraction()' now takes keyword
         arguments, but not a 'request'.  The 'IWebTraversable' interface no longer
         has a 'getObject()' method, and the 'IWebException.handleException()'
         method signature has changed as well.  Finally, all methods that
         previously accepted 'ITraversalContext' (such as
         'IDOMletState.renderFor()') now expect 'environ' mappings.
   
       * 'web.TestInteraction' was replaced with 'web.TestPolicy', and
         'web.Interaction' was removed, since 'IWebInteraction' is no longer part
         of the architecture.
   
    - The 'log()' method of PEAK loggers ('logs.ILogger') now accepts a level name
      *or* a number, for convenient invocation.
   
    - SQL transaction semantics have changed.  Now, issuing an SQL statement
      *always* causes the connection to join the active PEAK transaction, even if
      you request that the SQL be issued "outside" a transaction.  Such SQL will
      be issued outside of the *database* transaction, but not outside of the
      PEAK transaction.  This simplifies the overall processing model for dealing
      with "untransacted" SQL such as Sybase DDL or read-only Oracle transactions.
      (In particular, the requirement that triggered this change was to allow
      Oracle read-only transactions to be released at the end of the current PEAK
      transaction.)  Also, got rid of the now-meaningless 'begin' command in n2.
   
    - The 'events.IEventSource' interface now returns a 'canceller' function from
      the 'addCallback()' method, allowing you to cancel a previously-scheduled
      callback.  This fixes a memory leak and performance problem with
      'events.AnyOf()', which previously could accumulate unneeded callbacks on
      the sources it was monitoring.  Note that if you have developed any custom
      event sources with 'addCallback()' methods, you must make sure that they
      return a canceller from now on.
   
    - Added 'ref:factory@addr1||addr2' URL scheme that maps to a corresponding
      'naming.Reference("factory",["addr1","addr2"])'.  'factory' can be either a
      dotted import string referencing a 'naming.IObjectFactory', or you can
      define a factory in the 'peak.naming.factories' property space.
   
    - Added a 'zconfig.schema' factory, so that 'ref:zconfig.schema@streamURL'
      will load a schema loader.  Schema loaders are themselves object factories,
      so you can do something like::
   
        [Named Services]
        peak.naming.factories.myschema = \
            naming.LinkRef('ref:zconfig.schema@pkgfile:mypkg/Schema.xml')
   
      in order to make URLs like 'ref:myschema@filename' work.  Note, by the way,
      that the above could also read::
   
        [Named Services]
        peak.naming.factories.myschema = \
            naming.Reference('zconfig.schema',['pkgfile:mypkg/Schema.xml'])
   
      which runs somewhat faster at lookup time.  Similarly, one can also use
      'naming.Reference("myschema",["somefile"])' in place of a
      'naming.LinkRef("ref:myschema@filename")'.  As well as being faster, for
      some use cases it's easier to 'Reference' directly than to glue together
      a 'ref:' URL string.
   
  - Fixed model.Element not getting parent component set when passed as a  
    constructor argument.  
   
  - Fixed property/utility lookups not working correctly on model.*  
    objects.  
   
  - Fixed IndentedStream generating all-whitespace lines  
   


Generate output suitable for use with a patch program
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