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Revision: 1181 - (download)
Tue Jun 10 21:11:48 2003 UTC (18 years, 1 month ago) by pje
File size: 14138 byte(s)
Misc. doc cleanups/enhancements.  Added info on 'invoke' command.
Fixes and Enhancements since Version 0.5 alpha 1

 Changed, Enhanced, or Newly Deprecated Features

 - Added a 'shellcmd:'  URL scheme that returns a function that calls
   'os.system()' on the body of the URL.  It's intended for use as a command
   factory, as is needed by the 'URLChecker' periodic task.

 - You can now define adapters from arbitrary types to 'binding.IBindingNode',
   and thus be able to use them as part of a component hierarchy - without
   needing to directly add 'getParentComponent()' or 'getComponentName()'
   methods to them.

 - Added experimental 'invoke.c' script for POSIX-ish platforms with funky
   '#!' support, or lack thereof.  'invoke' is designed to be used like this::

     #!/usr/local/bin/invoke peak somearg otherarg...

 This should work on most sane platforms with a long-enough commandline.
 (See http://homepages.cwi.nl/~aeb/std/hashexclam-1.html for details on the
 insanely incompatible ways different Unixes interpret #! lines.)

 The script is not currently built or installed by setup.py.  On the
 platforms it's targeted at, you should be able to build it with::

     gcc -o invoke invoke.c

 (Yes, it really is that simple of a script.)

 - Added a ZConfig schema for 'running.commands.EventDriven' applications,
   a ZConfig component definition for adaptive tasks, and a running shortcut
   called 'EventDriven'.  It should now be possible to do this::

     #!/usr/bin/env peak EventDriven

 at the top of a ZConfig file formatted according to the new schema, and
 have it run.  There are two periodic tasks that can be configured and
 run from such a file: 'CleanupFiles' and 'URLChecker'.  'CleanupFiles' will
 delete files matching a pattern that are older than a certain age, while
 'URLChecker' will check to see if the target of a naming system URL is
 up/available/working, and if not, runs a command to restart it.  As an
 amusing demo, try specifying a 'file:' URL with a 'shellcmd:touch theFile'
 to recreate the file, then add a 'CleanupFiles' that deletes the file the
 checker looks for.  This can be hours (well, minutes) of exciting fun as you
 watch the dueling daemons undoing each others' work.

 - Added 'zconfig.schema' URL scheme that loads an enhanced ZConfig schema
   object that can act as a command line interpreter using the 'peak' script.
   To use it, run 'peak zconfig.schema:urlToSchema urlOfConfig'.  Or, add
   a line like this::

     #!/usr/bin/env peak zconfig.schema:pkgfile:some.package/schema.xml

 to the top of a configuration file, and make the configuration file
 executable.  Note that the schema specified must convert to an object
 that's usable with the commands bootstrap framework.  Also note that
 if you have a local PEAK_CONFIG file, you can add a 'peak.running.shortcuts'
 entry to shorten the URL reference in your #! line.  E.g.::

     #!/usr/bin/env peak mySchema

 will suffice if you have defined 'peak.running.shortcuts.mySchema' as

 There is also a 'peak ZConfig urlOfSchema urlOfConfig' variant, that was
 added to support putting '#!/usr/bin/env peak ZConfig' at the top of
 schema files, but unfortunately that's not valid XML.

 - Standardized file-based URL syntaxes (e.g logfiles and lockfiles) to
   follow RFC 1738/2396, and Python 'urllib'.  This shouldn't affect much
   besides the canonical forms of the URLs.  Added 'pkgfile:some.pkg/filepath'
   URL syntax for ease of referring to files near modules.  (A convenience
   intended mainly for referencing ZConfig schemas.)

 - Added the UML 1.4 metamodel, and thus the ability to load UML 1.4
   models encoded in XMI 1.1.

 - Added support in the mof2py code generator for "unprefixing" enumerated
   values, so that UML and other metamodels' enumerations work correctly
   when loading from XMI.  Also, mof2py no longer emits 'config.setupModule()'
   calls in generated code, as in practice they are not needed.

 - Running 'peak test' from the command line is roughly equivalent to running
   'unittest.py', except that the test suite defaults to the PEAK test suite.
   You can, however run any test suite from the command line with a dotted
   module/attribute path, e.g 'peak test foo.bar.test_suite'.

 - 'binding.Acquire()' now accepts a 'default' value argument, and
   'binding.New()' no longer accepts the 'bindToOwner' flag.

 - There is a new 'binding.IComponentKey' interface that is used to implement
   'IComponent.lookupComponent()'.  Now you can implement this interface,
   or create an adapter for it, in order to make an object usable as an
   argument to 'binding.lookupComponent()' - and therefore usable as a key
   for 'binding.bindTo()' or 'binding.bindToSequence()'.  Not that it's
   necessarily very useful to do so; you're probably better off simply
   creating a naming scheme.  But it might be useful for lookups done
   in the context of classes, since naming schemes aren't usable there.
   (It was actually added in order to factor out all the type testing that
   'lookupComponent' used to do, so it doesn't matter if it's useful for
   much else.)

 - PEAK has been refactored to avoid the use of 'isImplementedBy()' and
   similar introspection, in favor of 'adapt()'.  As a result, some
   'peak.naming' interfaces have changed.  This should not affect you
   if you are only subclassing PEAK-provided naming components and not
   implementing these interfaces "from scratch".  However, the various
   'isAddress', 'isAddressClass', 'isResolver', and 'isName' APIs have
   also been removed, as they were based on 'isImplementedBy()'.

 - REMOVED ability to use '__implements__' and '__class_implements__' to
   declare support for interfaces.  Use 'protocols.advise()' or a related
   API to do this now.  The 'protocols' package is available automatically
   from 'peak.api'.

   Similarly, the ability  to use 'isImplementedBy()' with interfaces declared
   by PEAK is REMOVED.  You can still use 'isImplementedBy()' with Zope
   interfaces, of course, but we recommend you switch to 'adapt()', which
   should work with both PEAK and Zope interfaces.

 - Replaced all use of 'zope.interface' with 'protocols' package because
   the 'protocols' package:

   * is considerably smaller and simpler than 'zope.interface'

   * produces Interface objects that can be inspected with the Python
     'pydoc' and 'help()' tools

   * supports and implements the PEP 246 'adapt()' protocol

   * transparently supports transitive adaptation - i.e. if adapter AB
     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)).

   * Supports "open protocols" that allow you to "superclass" a protocol
     to create a subset protocol; objects that support the first protocol
     will automatically support the subset protocol.  For example, if one
     person defines a "dictionary" protocol, someone else can create a
     "read-only dictionary" protocol, and all objects supporting the
     "dictionary protocol" will be considered to implement the "read-only
     dictionary" protocol.

   * can interoperate with other interface packages, including Zope's, but
     does not require them

   * works with module inheritance (for everything but moduleProvides(), and
     we should get to that by 0.5a2)

   * lets you use Interfaces as abstract base classes (i.e., you can
     inherit from an interface and turn it into an implementation, and
     you can define default attribute values or method implementations in
     your interfaces

   * Lets you mix interface declarations from any number of frameworks and
     any number of interface types, in a single 'implements()' or

   * uses adaptation as the fundamental approach to dealing with interfaces,
     and avoids the use of 'isImplementedBy()'.  In the *rare* case that you
     need to introspect rather than adapt, you can always call adapt() and
     check the result.  (But introspection usually means that you're using
     interfaces as a form of metadata; it's better to create an explicit
     interface that provides the metadata you seek, and adapt to that
     interface, than to use interfaces as data.)

   Most of these features are unavailable in 'zope.interface', and some have
   been declared by the Zope Pope to be unacceptable or undesirable features
   for Zope interfaces.  (Others may be available in some form in future
   versions of Zope X3.)  So, we no longer require or distribute

 - The signatures of the 'getObjectInstance()', 'getStateToBind()', and
   'getURLContext()' methods in the 'peak.naming' package have changed, to
   place the context or parent component as the first, non-optional argument.
   (If you don't know what these methods are for, you don't need to do anything
   about this, as they are part of the naming package's extensibility

 - 'binding.bindTo()' now accepts a 'default=' argument, whose value will be
   used in case of a 'NameNotFound' error.

 - DEPRECATED 'naming.ParsedURL'.  It will disappear in 0.5 alpha 3 or beta.
   It is replaced by the new 'naming.URL.Base'.  The 'naming.URL' package
   provides a new URL parsing framework based on 'peak.model'.  Upgrading from
   'ParsedURL' to 'URL.Base' is trivial for ParsedURL subclasses that used
   only the 'scheme' and 'body' fields, and in fact may not require any
   changes except for the choice of base class.  Also, the 'retrieve()' method
   of URLs is deprecated; please begin defining the 'getObjectInstance()'
   method instead.  This is to cut down a bit on the number of ways that the
   naming package spells the idea of retrieving something!

   For more complex URL classes, the '__init__' methods go away, 'parse'
   methods change slightly, and explicit field definitions (using
   'model.structField' or similar) are required.  See PEAK's 'URL.Base'
   subclasses for examples.  There is also a sophisticated parsing and
   formatting framework (see the 'peak.naming.URL' and 'peak.util.fmtparse'
   modules) that can be used in place of the old regex-based approach.

 - Added 'peak.util.fmtparse', a parsing and formatting framework, and
   integrated it with 'peak.model' so that any element type can have a
   syntax for parsing from, or formatting to, a string.

 - Added 'binding.whenAssembled(...)' as syntax sugar for

 - Removed 'LOG_XYZ' convenience functions from 'peak.api', and refactored
   'peak.running.logs' to use a PEP 282-like interface, 'running.ILogger'.
   Under the new scheme, messages must be sent to a specific entry point
   (e.g. 'self.logger.warning("foo")').  Components can bind an attribute
   directly to a logger object, or via configuration properties or utilities.
   PEAK components that do logging all define a 'logger' attribute, bound
   to a configuration property in the 'peak.logs' property namespace.  By
   a default in 'peak.ini', 'peak.logs.*' is configured to output messages
   of 'WARNING' priority or higher to 'sys.stderr'.

   For compatibility with the PEP 282 logging package, a 'logging.logger:'
   URL scheme has been added; looking up the URL '"logging.logger:foo.bar"'
   is equivalent to 'logging.getLogger("foo.bar")', unless the 'logging'
   package is not available, in which case the configuration property
   '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
   that it only uses PEAK loggers, and never uses the PEP 282 loggers.

 - Added 'binding.metamethod()' wrapper for metaclass methods that might
   not be accessible from their instances if the instances (classes) also
   defined the method for *their* instances.  You must now use this wrapper
   on any such metaclass-defined methods, as PEAK no longer works around
   this via the 'x.__class__.foo(x,...)' trick that was used previously.
   In particular, if you have metaclass definitions of 'getParentComponent',
   '_getConfigData', 'getComponentName', or 'notifyUponAssembly', you need
   to wrap them with 'binding.metamethod' now.

 - Made 'NOT_GIVEN' and 'NOT_FOUND' recognizable by humans (they 'repr'
   and 'str' to their names) and by Python (they can be pickled, and
   when restored they come back as the same object).

 Corrected Problems

 - Fixed a problem in ZConfig 'schema.dtd'; I used 'PCDATA' where I should've
   used 'CDATA'.

 - Fixed a problem with 'binding.supertype()' not working correctly if the MRO
   it was searching contained a "classic" class.  Now 'supertype()' skips any
   classic classes it finds.  (It probably should be rewritten entirely.)

 - Fixed misc. problems with 'fromZConfig()' component constructor

 - Fixed source distributions missing essential setup files

 - Fixed a problem with assembly events, where a parent component that didn't
   need assembly notification, wouldn't ever notify its children of assembly
   if they requested the notification after the parent had already received

 - Fixed a bug in automatic metaclass generation that caused extra unneeded
   metaclasses to be generated.

 - Fixed 'naming.lookup()' and related APIs not setting the parent component
   of created objects without an explicitly supplied 'creationParent' keyword
   argument.  This used to "sort of work" when we had implicit configuration
   parents, but was broken when we went "all explicit" for 0.5 alpha 1.

 - Fixed a problem where initializing single-valued immutable fields of
  'peak.model' types did not perform type/value normalization.

 - Fixed a problem where bindTo would use the attribute name as the
   default value for a lookup, if the requested name/property/utility
   was not found.

 - Fixed 'mof2py' generator script not working

 - Fixed model.Element not getting parent component set when passed as a
   constructor argument.

 - Fixed property/utility lookups not working correctly on model.*

 - Fixed IndentedStream generating all-whitespace lines


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