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version 1205, Wed Jun 25 21:05:33 2003 UTC version 1689, Thu Feb 12 19:56:17 2004 UTC
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  Changed, Enhanced, or Newly Deprecated Features   Changed, Enhanced, or Newly Deprecated Features
   
  - There is now a 'peak.security' package, available from 'peak.api' as   - Added 'model.Repr' type, useful for doing eval/repr conversions of simple
    'security'.  It provides permission management functions: you can define     Python types, and changed the N2 'htmldump' command to use it.
    abstract permissions by subclassing 'security.Permission', then create  
    permission checking rules by subclassing 'security.RuleSet', and declare  
    the permissions needed to access attributes of a class with  
    'security.allow()'.  The test suite demonstrates a complex application  
    ruleset with dynamic, data-driven permissions.  
   
  - There is now an interface for "Active Descriptors":   - Added 'peak.util.mockets', offering imitation socket services like
    'binding.IActiveDescriptor'.  'peak.binding' now uses this interface to     'socket()' and 'select()', allowing socket-based services to be tested
    identify active descriptors, so you can now create your own.  (Previously,     without using real sockets.
    'peak.binding' used 'isinstance()' to detect active descriptors.)  
    - Added limited support for two-phase commit of database connections to Sybase
      and Oracle.  Changed Oracle "outside transaction" semantics to allow read
      operations only, and added a property to set Oracle transactions to
      "serializable" (which effectively requires two-phase commits).  Note that
      the current version of DCOracle2 doesn't properly support two-phase commit
      except for empty (no-op) transactions, which isn't very useful.  However, if
      a later release of DCOracle2 works correctly and doesn't change its API, the
      current PEAK driver should then work correctly.  In the meantime, the
      cx_Oracle driver apparently *does* provide working support for two-phase
      commits.  The controlling properties are of the form 'DRIVER.twoPhaseCommit'
      and 'DRIVER.serializable', where 'DRIVER' is the name of the DBAPI driver
      module, e.g. 'Sybase.twoPhaseCommit' or 'cx_Oracle.serializable'.
   
    - Added properties to the command-line applications framework, allowing
      non-command objects access to 'stdin', 'stdout', 'argv' etc. from their
      context.
   
    - Added '[Named Services]' section parser to 'peak.ini'.  This new section
      type functions similarly to '[Component Factories]', except that
      the keys are property names rather than references to interfaces or other
      component keys, and the values are an expression that creates the actual
      instance, rather than the name of a factory for the service  This should be
      helpful for configuring shared services that all implement the same
      interface, such as SQL connection objects.
   
      Note that to look up a named service, you simply use the appropriate
      property name, as usual.  The difference is that you are guaranteed to
      always use the same *instance* of the service, within a given service area.
   
    - Added 'peak serve' and 'peak launch' commands, for running "CGI" apps in
      a browser from the local machine.  For example, doing this::
   
       PYTHONPATH=examples/trivial_cgi peak launch import:the_cgi.DemoCGI
   
      from the base directory of a PEAK CVS checkout or source distribution will
      launch the 'trivial_cgi' demo program in a new or current browser window.
      Any application runnable with 'peak CGI' should also be runnable with
      'peak serve' or 'peak launch', which makes it very useful for running
      local browser-based apps or testing an application without CGI or FastCGI
      available.  The modules that support this new functionality are
      'peak.util.WSGIServer' (which implements a web server based on Python's
      'BaseHTTPServer', that can run 'running.IRerunnableCGI' objects) and
      'peak.tools.local_server' (which provides PEAK integration.)
   
    - Added 'peak.ddt' framework for Document-Driven Testing.  DDT can parse HTML
      files to extract test descriptions from HTML tables, run the tests, and then
      output an annotated version of the input document, illustrating the results
      by e.g. coloring cells to highlight good/bad results.  To use it, you must
      implement 'ddt.ITableProcessor' components that know how to interpret the
      table contents.
   
    - Added 'fd.file:' URL scheme, for URLs like 'fd.file:stdin' that can be used
      in place of 'file:' URLs for many purposes.
   
    - Added 'model.ExtendedEnum', for enumerations that also support arbitrary
      integers.
   
    - Added 'events.IEventLoop' implementation and refactored 'UntwistedReactor'
      to use it.  'UntwistedReactor' is now nothing more than an adapter from
      'events.IEventLoop' to 'running.IBasicReactor'.  Added 'twisted_support'
      versions of 'peak.events' interfaces (untested).
   
    - 'running.ISignalManager' is now DEPRECATED; please use 'events.ISignalSource'
      instead.
   
    - Added 'events.ISignalSource', that returns 'events.Broadcaster' objects for
      signals.  This allows you to yield to signals in an 'events.Thread', or
      safely set one-time callbacks on them.
   
    - 'running.IMainLoop' has been changed to use an 'events.IReadable' for
      the 'lastActivity' attribute, and the 'setExitCode' and 'childForked'
      methods have been replaced with an 'exitWith()' method.
   
    - The 'peak.running.mainLoop.signalHandler' property has been replaced with
      'peak.running.mainLoop.stopOnSignals', which defaults to including SIGINT,
      SIGTERM, and SIGBREAK.  If you need custom signal handling, please use
      the event sources provided by an 'events.ISignalSource'.
   
    - Simplified configuration for using Twisted, roughly as proposed in
      "this message.":http://www.eby-sarna.com/pipermail/peak/2004-January/001125.html
   
      You can now configure a service area as using Twisted by setting its
      'peak.events.isTwisted' property, or by depending upon the
      'running.ITwistedReactor' interface, as long as it happens early enough.
   
      If you need to make choices based on whether a Twisted reactor is being
      used, you should use the 'events.ifTwisted()' function.  If you would like
      to try to force a service area to use a Twisted reactor, you may use
      'events.makeTwisted()'.
   
    - Added automatic installation of 'csv' module for Python < 2.3.
   
    - Added 'peak.events' package, supporting a simple event-driven programming
      microkernel, including event-driven "ultralight" threads powered by
      generators.
   
    - "Global" services defined by '[Component Factories]' sections now live in
      the closest "service area" to the component that requests them.  A "service
      area" is a parent component that implements 'config.IServiceArea', such as
      a configuration root returned by 'config.makeRoot()'.  Applications loaded
      by the 'peak runIni' command are now created in their own service area,
      which means that settings in the .ini file being run will apply to services
      the application uses.  (Because the application will have its own,
      application-specific service instances, and they will use the configuration
      loaded into the service area.)
   
      If you need to create your own service area, you can do so by mixing in
      'config.ServiceArea' to your component class.  However, you should *not* do
      this unless you know exactly what "outside" services you may need to use
      from "inside" the newly created service area, so that you can explicitly
      connect them "into" the service area.  (In short, if you don't know *why*
      you're creating a service area, don't do it.)
   
    - 'config.Namespace()' objects now have a 'keys()' method that can be used
      when the namespace is bound to a context component.  It returns a list of
      strings that may be used as keys for that namespace.  Example usage::
   
       >>> from peak.api import *
       >>> r=config.makeRoot()
       >>> ns=config.Namespace('peak.naming.schemes',r)
       >>> ns.keys()
       ['https', 'smtp', 'logfile', 'psycopg', 'pkgfile', 'unix.dg', 'win32.dde',
       'sybase', 'timer', 'lockfile', 'pgsql', 'fd.socket', 'uuid', 'tcp', 'file',
       'gadfly', 'http', 'logger', 'icb', 'cxoracle', 'udp', 'winflockfile',
       'import', 'logging.logger', 'nulllockfile', 'nis', 'shlockfile',
       'zconfig.schema', 'flockfile', 'shellcmd', 'dcoracle2', 'config', 'ftp',
       'unix', 'ldap', 'sqlite', 'mockdb']
       >>> ns['ldap']
       'peak.storage.LDAP:ldapURL'
   
    - Log events don't use a positional 'message' argument any more, and
      loggers aren't responsible for interpolating message arguments any more.
      The new signature is 'Event(parent, msg=msg, args=args, ...)'.  Loggers
      also now tell events what logger name they are, via the 'ident' keyword.
   
    - The logging system now uses a property namespace, 'peak.logging.levels', to
      obtain log level names and values.  The various 'logs.LEVEL' constants are
      now DEPRECATED.  Please use the 'getLevelFor()' method of the nearest
      'logs.ILoggingService' instead.  Also note that URL schemes such as
      'logfile:' no longer convert their level names to numbers, since the
      level names are only meaningful in the context of a logging service.
   
    - Support for integration with the Python 2.3/PEP 282 logging module has been
      scaled back.  There are too many globalisms and dependencies there.  When we
      add plugin-based log configuration, it should be possible to use the logging
      package's handlers and formatters with the PEAK logging services.  At that
      point, you'll be able to replace 'logging.getLogger' and
      'logging.getLevelName' with the corresponding methods of a PEAK logging
      service, if you need to force non-PEAK packages to use PEAK's logging.
   
    - Logs are now accessed via a 'logs.ILoggingService' instance.  The 'logger:'
      URL scheme automatically accesses the nearest such service.  For backward
      compatibility, the old 'peak.logs' namespace is still used to supply the
      actual loggers.  This will be gradually replaced with a plugin-based
      mechanism.
   
    - Added 'binding.PluginKeys' and 'binding.PluginsFor'.  These are component
      keys that can be used to 'Obtain' plugins registered within a property
      namespace.  'PluginKeys' obtains a list of the plugins' configuration keys,
      while 'PluginsFor' obtains a list of the actual plugins.
   
    - Replaced 'peak.config.registries.EigenRegistry' with
      'peak.config.registries.ImmutableConfig'.  The only use we had for
      'EigenRegistry' was to keep track of 'offerAs' settings within classes, and
      it didn't need all the extra complexity of eigenstate management.  The new,
      more-specialized class is shorter, simpler, and easier to use.
   
    - Added 'config.iterKeys()' which iterates over all available configuration
      keys in a given namespace (just property names for now).  The 'config:'
      namespace is now a 'naming.IReadContext', so you can navigate it with the
      'n2' command, and do things like 'ls -l config:peak.naming.schemes' to list
      all configured naming schemes.
   
    - Added 'config.parentProviding()' and 'config.parentsProviding()', which
      find the first (or all) parent components of a given component that support
      a given protocol.
   
    - Renamings/refactorings/deprecations in 'peak.config':
   
       'config.getProperty' -- use 'config.lookup()' instead
   
       'config.findUtility' -- use 'config.lookup()' instead
   
       'config.findUtilities' -- use 'config.iterValues()' instead
   
       'config.IPropertyMap' -- use 'config.IConfigMap' or 'config.IConfigurable'
   
       'config.PropertyMap' -- use 'config.ConfigMap' instead
   
       'config.setPropertyFor' -- DEPRECATED, see source for replacement code.
   
       'config.setRuleFor' -- DEPRECATED, see source for replacement code.
   
       'config.setDefaultFor' -- DEPRECATED, see source for replacement code.
   
       'config.instancePerComponent' -- DEPRECATED, use factories instead.
   
       'config.IConfigurationRoot' -- interface has changed; 'propertyNotFound' is
       no longer a method, and 'noMoreUtilities' is now 'noMoreValues'.
   
       'exceptions.PropertyNotFound' -- use 'exceptions.NameNotFound' instead.
   
       'exceptions.OutOfScope' -- REMOVED; it was not actually used in PEAK.
   
      In all cases, the old interface, class, or function is DEPRECATED and will
      go away in the alpha 4 release cycle.  Please take particular note of the
      fact that 'IConfigMap' offers virtually none of the convenience
      methods provided by 'IPropertyMap', so adjust your code accordingly.  Note
      also that even though there are plenty of references to 'IPropertyMap'
      remaining in PEAK itself, these are strictly to provide backward
      compatibility.  Once we enter the alpha 4 release cycle, these will go away.
   
    - Added 'config.MultiKey()' and 'config.UnionOf()' configuration key classes,
      to generalize existing specialty keys such as 'ProviderOf' and 'FactoryFor'.
      (The latter two are now defined in terms of the former two.)  Also, made
      classes and types usable as configuration keys.  This was needed for the
      above generalization, but also makes many other class-lookup concepts
      possible.  (Note that there may be some slight changes to the effective
      registration and lookup order of these and other configuration keys as of
      this change, as there were some previous errors and/or ambiguities to the
      lookup order that were not covered by the test suite.)
   
    - Added "[Import on Demand]" section type to .ini files, allowing you to
      define shortcuts for modules that you frequently reference in your
      configuration.  This lets you replace e.g. 'importString("foo.bar.baz:Spam")'
      with 'foo_baz.Spam' in expressions, by adding something like this::
   
       [Import on Demand]
       foo_bar = "foo.bar.baz"
   
      to your configuration.  The defined shortcut is then available for the
      remainder of that configuration file, and in any .ini files included from
      the current file.  See 'peak.ini' for an example and more info.
   
    - Logging-related interfaces have been moved into the 'peak.running.logs'
      module.  So, what used to be 'running.ILogger' is now 'logs.ILogger'.
   
    - Log events now use a standard component construction signature, and the
      class used for event objects is now configurable as the factory for
      'logs.ILogEvent'.  (See "[Component Factories]" in 'peak.ini'.)
   
    - By popular demand, 'logs.ILogger' (and its default implementation) now
      includes 'trace()', 'notice()', 'alert()' and 'emergency()' methods that use
      the corresponding 'syslog' priority levels.  'logs.IBasicLogger' has been
      added, to reflect the narrower interface provided by PEP 282, and there is
      an adapter that can extend PEP 282 loggers with the other methods.
   
    - The 'logging.logger:' URL scheme has been simplified to 'logger:'.  Please
      convert your scripts and configuration files, as the longer form will go
      away in the alpha 4 development cycle.
   
    - Added 'commands.lookupCommand()' to look up a command shortcut or URL, ala
      the 'peak' script or 'commands.Bootstrap' class.  Also added various
      'commands.ErrorSubcommand' subclasses to make it easier to issue errors
      from/for subcommands.
   
    - Added 'peak.core' as a minimal subset of 'peak.api'.  'peak.core' offers
      only "core" API packages and primitives, not the full set of available
      framework APIs.  'peak.api' will continue to expand as frameworks are added,
      but 'peak.core' will stay as small as practical.  ('peak.exceptions' may in
      fact end up being removed from 'peak.core', or at least renamed.)
   
    - Added 'peak.util.symbol' module, to contain 'NOT_GIVEN', 'NOT_FOUND', and
      the 'Symbol' class used to create them.
   
    - 'peak.running.tools' was promoted to 'peak.tools'.  'peak.running.supervisor'
      was also moved to 'peak.tools.supervisor', and a new 'peak help' command was
      added in 'peak.tools.api_help'.
   
    - Replaced the "[Provide Utilities]" section of .ini files with "[Component
      Factories]".  The new section type is easier to use, much more versatile,
      and does all registration and imports lazily.  See the 'peak.ini' file for
      docs.  "[Provide Utilities]" and 'config.ProvideInstance()' are now
      DEPRECATED, so please convert ASAP.
   
    - 'binding.Make()' now accepts configuration keys, using them to look up a
      factory object that's then invoked to create the attribute.  This makes it
      a lot easier to define a component with its own transaction service
      or other normally "global" component.  It also makes it easier to globally
      specify a factory class for some interface.  Factories are looked up under
      the 'config.FactoryFor(key)' configuration key.  (See below.)
   
    - Added 'config.FactoryFor(key)', a 'config.IConfigKey' implementation that
      provides a configuration namespace for factories.
   
      When you use 'binding.Make(ISomething)', it's roughly equivalent to::
   
           binding.Make(
               lambda self,d,a:
                   binding.lookupComponent(
                       self, config.FactoryFor(ISomething),
                       adaptTo = binding.IRecipe
                   )(self,d,a)
           )
   
      That is, the 'config.FactoryFor(ISomething)' is looked up and invoked.
   
    - Added 'config.CreateViaFactory(key)', a 'config.IRule' implementation that
      creates an implementation of 'key', by looking up 'config.FactoryFor(key)'
      and invoking it.
   
    - Added 'config.ruleForExpr(name,expr)', that returns a 'config.IRule' that
      computes the Python expression in the string 'expr'.  This is the mechanism
      used by configuration files to create rules, factored out into an API call
      so that configuration extensions can use it, too.
   
    - The 'referencedType' of a 'model.StructuralFeature' can now be any
      'binding.IComponentKey', not just a type or a string.  Types are also now
      implicitly component keys, which means you can use 'binding.Obtain(SomeType)'
      to look up 'SomeType'.  (Right now, this is no different than using 'SomeType'
      without the 'binding.Obtain()', but in future releases this will use a
      "class replacement service" to allow easy replacement of model and other
      collaborator classes, while implementing AOP-like features.)
   
    - Added 'naming.Indirect(key)', a 'binding.IComponentKey' that can be used to
      do an indirect lookup via another 'IComponentKey' (such as a name).
   
      Using 'naming.Indirect()', you can replace code like this::
   
           socket = binding.Obtain(
               lambda self: self.lookupComponent(self.socketURL),
               adaptTo=[IListeningSocket]
           )
   
      with code like this::
   
           socket = binding.Obtain(
               naming.Indirect('socketURL'), adaptTo=[IListeningSocket]
           )
   
    - Added 'peak.tools.supervisor', a mini-framework for pre-forking,
      multiprocess servers, such as for FastCGI.  The framework includes a ZConfig
      schema for process supervisors, and support for automatically forking new
      children (up to a predefined maximum, with a minimum interval between
      launches) when a socket has pending connections and all of its child
      processes are busy.  With this setup, you can take more advantage of
      multiprocessor machines for CPU-intensive services.
   
    - Standardized these characteristics of name and address syntax:
   
      * '//' at the beginning of URL bodies is *mandatory* when the URL begins
        with an "authority" as described by RFC 2396.  When the URL is not
        required to contain an authority (e.g. 'peak.storage.SQL.GenericSQL_URL'),
        the '//' is *optional*, and the canonical form of the URL will not include
        it.
   
      * Standardized names for RFC 2396 fields: 'user', 'passwd', 'host', and
        'port'.
   
  - 'peak.naming' no longer automatically converts all addresses to the   - Added 'peak.metamodels.ASDL', a metamodel for the Zephyr Abstract Syntax
    addressed objects.  You must specifically request the interface you want     Description Language.  ASDL is a convenient way to describe a domain model
    by adapting the retrieved object to that interface.  This can be done by     for an abstract syntax tree (AST), and the models generated with the new
    supplying an 'adaptTo=ISomething' keyword argument to the attribute binding     ASDL tool can be combined with concrete syntax to create a complete parsing
    definition or your 'lookupComponent()' call.     solution for "mini languages", possibly including the Python language
      itself.  (Future versions of the Python and Jython compilers are likely to
    The naming system no longer has 'objectFactories' and 'stateFactories';     use AST models based on ASDL, and in the current Python CVS sandbox there's
    these have been replaced with adaptation.  Writable naming contexts must     already an ASDL model of Python's AST available.)
    have a 'serializationProtocol' attribute specifying what interface an object  
    should be adapted to before attempting to store it in that context.   - Enhanced 'fmtparse' and 'peak.model' to allow using types as syntax rules
      for parsing, including abstract types.  An abstract type's syntax is the
      union (using 'fmtparse.Alternatives') of the syntaxes of its subclasses
      (as specified by 'mdl_subclassNames').
   
    - Added 'IMainLoop.exitWith()' method, to allow reactor-driven components to
      control the mainloop's exit code.
   
    - Added 'IBasicReactor.crash()', which forces an immediate reactor loop exit,
      ignoring pending scheduled calls.
   
    - Added 'peak.running.commands.runMain()', a convenience function for starting
      an application's "main" command, that also makes it easy for forked child
      processes to exit and replace the parent process' "main".  The 'peak' script
      has now been shortened to::
   
          from peak.running import commands
          commands.runMain( commands.Bootstrap )
   
      so it's now much easier to create alternative startup scripts, if you need
      to, or to add an 'if __name__=="__main__"' clause to a module.
   
    - Added 'peak.util.mockdb', a "mock object" implementation of a DBAPI 2.0
      driver module.  'mockdb' connections can be told to 'expect()' queries
      and 'provide()' data to their callers, and will raise AssertionErrors when
      they are used in a way that doesn't conform to your supplied expectations.
      This is intended to be used for unit testing components that depend on
      a database connection: you can verify that they send the right SQL, and
      you can provide them with dummy data to use.  There is also a 'mockdb:' URL
      and peak.storage driver, so you can easily use a mock DB connection in place
      of a real one within a PEAK application, for testing purposes.  Note,
      however, that 'peak.util.mockdb' is a DBAPI 2.0 driver in itself, and thus
      can also be used to test DBAPI usage outside of PEAK.
   
    - SQL connection objects now provide an 'appConfig' attribute that is a
      driver-specific 'config.Namespace()'.  This allows you to easily set up
      configuration properties that are driver-specific.  For example, you could
      use properties to configure driver-specific SQL snippets, then access them
      via the connection's 'appConfig' namespace.  The namespaces are of the form
      'DRIVER.appConfig', where 'DRIVER' is the name of the DBAPI module for that
      connection type (e.g. 'pgdb', 'cx_Oracle', etc.).
   
    - Added 'config.Namespace()' convenience class for redirecting property
      lookups from one namespace to another.  See the docstring and 'peak.ini' for
      usage examples.  'PropertyName.of()' now returns 'Namespace' instances
      instead of 'PropertySet' instances.
   
    - DEPRECATED the 'config.PropertySet' class; please convert to using
      'config.Namespace', as 'PropertySet' will disappear in the 0.5alpha4 release
      cycle.
   
    - SQL connection objects now get their type converters from a distinct
      property namespace for each DBAPI driver.  For example a driver using the
      'cx_Oracle' module will get its type converters from the
      'cx_Oracle.sql_types' property namespace, instead of 'peak.sql_types'.  For
      backward compatibility, these driver-specific namespaces are set up to
      fall back to 'peak.sql_types' for their defaults.  Type converter
      construction has also been improved, to eliminate conversion overhead
      completely when no conversions are required for a specific query.  Also,
      SQL connections now offer a method that will create a row conversion
      function for a given result description and optional postprocessing
      function.  This new method should now be used in place of direct access to
      the 'typeMap' attribute of connection objects.
   
    - Added 'binding.Require', 'binding.Obtain', 'binding.Make', and
      'binding.Delegate'.  *ALL* other binding types are now DEPRECATED, and will
      go away before 0.5 beta is released:
   
      'requireBinding("info")' -- use 'Require("info")'
   
      'delegateTo("attr")' -- use 'Delegate("attr")'
   
      'New(type)' -- use 'Make(type)'
   
      'New("module.type")' -- use 'Make("module.type")'
   
      'bindTo(key)' -- use 'Obtain(key)'
   
      'Constant(value)' -- use 'Make(lambda: value)'
   
      'Acquire(key)' -- use 'Obtain(key, offerAs=[key,])'
   
      'Copy(value)' -- use 'Make(lambda: <expr to copy value>)'
   
      'whenAssembled(func)' -- use 'Make(func, uponAssembly=True)'
   
      'bindSequence(key1,key2,...)' -- use 'Obtain([key1,key,...])'
   
      'bindToProperty(x,y)' -- use 'Obtain(PropertyName(x),default=y)'
   
      'bindToParent()' -- use 'Obtain("..")'
   
      'bindToSelf()'  -- use 'Obtain(".")'
   
      'bindToUtilities()' -- no replacement; let me know if you're using this.
   
      Note that 'Make' and 'Obtain' also support sequences of recipes and keys,
      and in those cases will produce a sequence of the results from those recipes
      or keys.  Also, 'Make' will accept no-argument and one-argument callables,
      where 'Once' always required three-argument functions.  This should make it
      a lot easier to write short binding functions.
   
      Also, note that the 'activateUponAssembly' keyword is now 'uponAssembly',
      and 'isVolatile' is now 'noCache'.  (The old names will work as keyword
      arguments until the alpha 4 development cycle begins.)  The
      'binding.IActiveDescriptor' interface also changed as a result of this.
      Last, but not least, a 'binding.IRecipe' interface was added, to support the
      new 'binding.Make' type.
   
   
    - Added a 'lockName' attribute to 'runnning.AdaptiveTask', and a 'LockURL'
      setting to its ZConfig schema.  This allows a lockfile URL to be specified
      for adaptive tasks that need exclusive access to some resource while
      running.
   
    - A list or tuple of 'IComponentKey' instances is now treated as a single
      component key, that returns a tuple of the values returned by each
      constituent component key.  This means that 'binding.Obtain()' and
      'lookupComponent()' can now accept a list or tuple of component keys.  This
      makes 'bindSequence()' obsolete, so 'bindSequence()' is now DEPRECATED.
      'binding.bindSequence(key1,key2,...)' can now be replaced with
      'binding.Obtain([key1,key,...])', and will produce the same results.
   
    - 'naming.IBasicContext.lookup()' and 'naming.lookup()' now accept a 'default'
      argument, similar to that used by 'lookupComponent()' and most other
      lookup-like APIs in PEAK.  This change was made so that component lookups
      don't need to rely on catching 'exceptions.NameNotFound' errors to tell them
      when to use the default value.  This could hide 'NameNotFound' errors that
      were actually from a broken component somewhere in the lookup process.  (In
      general, it's probably a bad idea to have an exception that's used for both
      control flow and real errors!)
   
    - Added new 'version' tool that automatically edits files to update version
      information in them.  Just execute the 'version' file in the main PEAK
      source directory.  (Use '--help' for help.)  You can use this tool with your
      own projects by creating 'version' and 'version.dat' files in your project
      directory, similar to the ones used by PEAK.  The 'version' file is a ZConfig
      file that describes your project's version numbering scheme(s), formats,
      and the files that need to be edited, while the 'version.dat' file contains
      the current version number values.  Source for the tool, including the
      configuration file schema, is in the 'peak.tools.version' package.
      (Error handling and documentation, alas, are still minimal.)
   
    - Added new 'Alias' command in 'peak.running.commands'.  An 'Alias' instance
      can be used as a 'peak.running.shortcut' property that expands to another
      command with arbitrary arguments inserted before the original command's
      arguments.  Thus, one might alias 'mycommand' to 'runIni somefile --option',
      similar to command aliases in many shells.
   
    - 'naming.IName' is now derived from 'binding.IComponentKey', so names and
      addresses must now support the 'findComponent()' method.  All PEAK name and
      address types provide support for this.
   
    - The 'lookup()' method of 'binding.IComponentKey' is now called
      'findComponent()', to better distinguish it from 'lookup()' in
      'naming.IBasicContext', which does something very different.
   
    - 'binding.Obtain()' (formerly 'binding.bindTo()' and 'binding.bindSequence()')
      now pre-adapt their arguments to 'IComponentKey', to speed up lookups at
      runtime, and to ensure that errors due to an unusable parameter type occur
      at class creation time instead of waiting until lookup time.
   
    - There's a new 'peak.storage.files' module, with handy classes like
      'EditableFile'.  'EditableFile' is a class that lets you edit the contents
      of a file "in place", with atomic replacement of the original at transaction
      commit.  If the transaction is aborted, the original file is left unchanged.
   
    - 'peak.running.scheduler.UntwistedReactor' now supports a configuration
      property ('peak.running.reactor.checkInterval') to determine how long it
      should run 'select()' calls for, when there are no scheduled tasks.
   
    - 'peak.running.commands.AbstractCommand' now offers a '_run()' method that
      can be overridden in subclasses, instead of 'run()'.  If you override the
      new '_run()' method instead, you get the advantage of automatic handling
      for invocation errors and 'SystemExit' exceptions, provided for you by the
      'run()' method.
   
    - There is now a 'storage.DMFor(class)' function that returns a configuration
      key for registering or looking up data managers by class.  You can use the
      returned key in a binding's 'offerAs' list, or as the target of a 'bindTo()'
      or 'lookupComponent()'.  The key is constructed using
      'config.ProviderOf(storage.IDataManager,class)'.
   
    - You can now register utilities that are keyed by the combination of an
      interface and one or more classes, using 'config.ProviderOf(iface,*classes)'
      as a configuration key.  Providers are registered under an '(iface,klass)'
      tuple for each specified class, and looked up using the MRO order of the
      class specified for lookup.  In other words, searching for a provider will
      find a provider for the requested class, or one of its base classes, with
      precedence given to the more-specific provider.  This is primarily intended
      for services like data managers and Specialists.
   
    - It's now possible to extend .ini file parsing with custom section types,
      and PEAK defines its own built-in section types using this extension
      mechanism.  Custom section types must include at least one space, (e.g.
      '[My Section]') or they will be treated as a plain property name.
      See the 'peak.config.iniFile.sectionParsers' section in 'peak.ini' for
      more details, along with the 'config.ISettingParser' and 'config.IIniParser'
      interfaces.
   
    - When creating a 'PropertyName()', it's now possible to force conversion of
      invalid characters to '_', using the 'PropertyName.fromString()'
      constructor.  (Note that the input must be a plain-ASCII string.)  Unless
      you request that wildcards ('?' and '*') be kept, they will also be
      converted to '_' characters.  This can be convenient for converting things
      like filenames or text that might contain spaces, to property names.
   
    - It's now possible to declare an attribute as offering a wildcard property;
      such lookups now follow the same rules as other wildcard property lookups.
      The 'config.IConfigKey' interface has been changed to cleanly support
      implied keys at both registration and lookup time, so you can implement
      your own key types that work the way interfaces or property names do for
      configuration lookups.
   
    - The 'EigenRegistry' class has been moved from 'peak.util.EigenData' to
      'peak.config.registries', as it hasn't really been useful outside PEAK for
      a while now.
   
    - .ini files now support "smart property" objects ('config.ISmartProperty').
      If a property rule defined in an .ini file evaluates at runtime to an object
      that implements 'ISmartProperty', the object will be given a chance to
      compute a value for the property, in place of being used itself.  This helps
      to simplify definition of complex property rules in .ini files, by allowing
      the use of helper classes.  Also, 'naming.LinkRef' and 'naming.Reference'
      (indirectly) support this interface, so you can now use them in .ini files
      to refer to an object via the naming system.  (Previously, 'naming.LinkRef'
      wouldn't do the right thing unless the property was looked up via a
      'config:' URL, and 'naming.Reference' didn't exist.)
   
    - 'peak.util.imports.whenImported()' can now be used even when the specified
      module has already been loaded.
   
    - The naming system no longer has 'objectFactories' and 'stateFactories' as
      utilities; they have been replaced with new mechanisms involving adaptation.
      Previously, addresses had a 'retrieve()' method that could be used to
      retrieve the object defined by the address.  Now, to retrieve an object for
      an address, you must either define a context that processes the address, or
      the address must have a 'defaultFactory' attribute, which provides a name
      to be imported to get an 'IObjectFactory' that can construct the referenced
      object.  (This is simpler than it sounds; for URLs that reference
      ManagedConnections, for example, all you need to do is provide the fully
      qualified name of the connection class.)
   
      Meanwhile, writable naming contexts must have a 'serializationProtocol'
      attribute, specifying what interface an object should be adapted to before
      attempting to store it in that context.
   
    The naming system no longer processes the 'creationName' keyword argument;     The naming system no longer processes the 'creationName' keyword argument;
    this is now considered the sole responsibility of 'peak.binding'.  The     this is now considered the sole responsibility of 'peak.binding'.  The
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    rather than a 'state,attrs' tuple.  For most naming contexts, this just     rather than a 'state,attrs' tuple.  For most naming contexts, this just
    means you should change 'return foo, None' statements to just 'return foo'.     means you should change 'return foo, None' statements to just 'return foo'.
   
    - Property definition rules in an .ini file can now refer to 'rulePrefix' and
      'ruleSuffix' variables.  'rulePrefix' is a "."-terminated string,
      representing the name the rule was defined with.  For example, if the
      rule was defined for '"foo.bar.*"', then 'rulePrefix' will be '"foo.bar."'
   
      The 'ruleSuffix' will be the portion of the 'propertyName' that follows
      'rulePrefix'.  So, if looking up property '"foo.bar.baz"', then the
      '"foo.bar.*"' rule will execute with a 'ruleSuffix' of '"baz"'.  This should
      make it easier to work with hierarchical property namespaces.
   
    - Added simple example scripts and small applications in the 'examples'
      directory.
   
    - There is a new command-line namespace introspection tool, 'n2', which
      can be accessed by running 'peak n2'.  Type 'peak n2 -h' for help.
   
    - The PEAK_CONFIG environment variable can now list multiple files, separated
      by the platform's 'os.pathsep' (e.g. ':' on Unix, ';' on Windows).
   
    - It's no longer necessary to provide a '_defaultState()' implementation
      for an EntityDM: a default implementation is now supplied.
   
    - Added automatic installation of 'datetime' package for Python < 2.3.
   
    - CGI support has been moved from 'peak.running.zpublish' into
      'peak.running.commands' (for "raw" CGI/FastCGI) and 'peak.web' (for the
      PEAK high-level publishing framework).  You can use 'peak CGI someName' to
      adapt 'someName' to a 'running.IRerunnableCGI' and run it as a CGI/FastCGI.
   
    - There is now a 'peak.security' package, available from 'peak.api' as
      'security'.  It provides permission management functions: you can define
      abstract permissions by subclassing 'security.Permission', then create
      permission checking rules by subclassing 'security.RuleSet', and declare
      the permissions needed to access attributes of a class with
      'security.allow()'.  The test suite demonstrates a complex application
      ruleset with dynamic, data-driven permissions.
   
    - There is now an interface for "Active Descriptors":
      'binding.IActiveDescriptor'.  'peak.binding' now uses this interface to
      identify active descriptors, so you can now create your own.  (Previously,
      'peak.binding' used 'isinstance()' to detect active descriptors.)
   
  - REMOVED 'naming.ParsedURL'; it was deprecated as of 0.5 alpha 2.   - REMOVED 'naming.ParsedURL'; it was deprecated as of 0.5 alpha 2.
   
  - The 'provides' keyword argument to various 'peak.binding' APIs has been   - The 'provides' keyword argument to various 'peak.binding' APIs has been
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    a binding to suggest a parent component, use 'suggestParent=False' in the     a binding to suggest a parent component, use 'suggestParent=False' in the
    binding definition.     binding definition.
   
   
   
   
   
   
   
   
 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 "this page":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  
    'naming.LinkRef("zconfig.schema:pkgfile:some.package/schema.xml")'.  
   
    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  
      'classProvides()'  
   
    * 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  
    'zope.interface'.  
   
  - 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  
    framework.)  
   
  - '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  
    'binding.Once(...,activateUponAssembly=True)'.  
   
  - 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   Corrected Problems
   
  - Fixed a problem in ZConfig 'schema.dtd'; I used 'PCDATA' where I should've    - 'peak.running.commands.CGICommand' could become confused on certain BSD
    used 'CDATA'.      variants (such as Mac OS/X), and assume it was running under FastCGI, even
       if it wasn't.  (Because the operating systems in question use socket pairs
  - Fixed a problem with 'binding.supertype()' not working correctly if the MRO      to implement pipes.)
    it was searching contained a "classic" class.  Now 'supertype()' skips any  
    classic classes it finds.  (It probably should be rewritten entirely.)    - Fixed some problems with the test suite when running under Python 2.3.
       PEAK itself worked fine, but the test suite was bitten by two minor
  - Fixed misc. problems with 'fromZConfig()' component constructor      semantic changes that took effect in 2.3, resulting in lots of error
       messages about ModuleType needing a parameter, and a test failure for
  - Fixed source distributions missing essential setup files      'checkClassInfo' in the 'FrameInfoTest' test class.
   
  - Fixed a problem with assembly events, where a parent component that didn't    - Transaction participants that raised an error in their 'abortTransaction()'
    need assembly notification, wouldn't ever notify its children of assembly      method, would not receive a 'finishTransaction()' call, the error was
    if they requested the notification after the parent had already received      passed through to the transaction service's caller, and later participants
    it.      might not have received an 'abortTransaction()' message either.
   
  - Fixed a bug in automatic metaclass generation that caused extra unneeded    - SQL connections didn't close their cursors before aborting a transaction
    metaclasses to be generated.  
     - The logging system would raise an error if a log message with no arguments
  - Fixed 'naming.lookup()' and related APIs not setting the parent component      contained a '%' sign.
    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    - There was a typo in peak.naming.arithmetic that caused homogeneous non-URL
    constructor argument.      name subtraction to fail.
   
  - Fixed property/utility lookups not working correctly on model.*    - The default reactor supplied in 'peak.running.scheduler' would consume
    objects.      CPU continuously if it was waiting for I/O and no tasks were scheduled.
   
  - Fixed IndentedStream generating all-whitespace lines    - The 'peak.util.imports.whenImported' function didn't work.
   


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