repoze.bfg 1.3a4

Support and Documentation

See the repoze.bfg website to view documentation, report bugs, and obtain support.

License

repoze.bfg is offered under the BSD-derived Repoze Public License.

Authors

repoze.bfg is made available by Agendaless Consulting and a team of contributors.

Features

• Undocumented hook: make get_app and get_root of the repoze.bfg.paster.BFGShellCommand hookable in cases where endware may interfere with the default versions.

• In earlier versions, a custom route predicate associated with a url dispatch route (each of the predicate functions fed to the custom_predicates argument of repoze.bfg.configuration.Configurator.add_route) has always required a 2-positional argument signature, e.g. (context, request). Before this release, the context argument was always None.

  As of this release, the first argument passed to a predicate is now a dictionary conventionally named info consisting of route, and match. match is a dictionary: it represents the arguments matched in the URL by the route. route is an object representing the route which was matched.

  This is useful when predicates need access to the route match. For example:

  def any_of(segment_name, *args):
      def predicate(info, request):
          if info['match'][segment_name] in args:
              return True
      return predicate
  
  num_one_two_or_three = any_of('num, 'one', 'two', 'three')
  
  add_route('num', '/:num', custom_predicates=(num_one_two_or_three,))

  The route object is an object that has two useful attributes: name and path. The name attribute is the route name. The path attribute is the route pattern. An example of using the route in a set of route predicates:

  def twenty_ten(info, request):
      if info['route'].name in ('ymd', 'ym', 'y'):
          return info['match']['year'] == '2010'
  
  add_route('y', '/:year', custom_predicates=(twenty_ten,))
  add_route('ym', '/:year/:month', custom_predicates=(twenty_ten,))
  add_route('ymd', '/:year/:month:/day', custom_predicates=(twenty_ten,))

• The repoze.bfg.url.route_url API has changed. If a keyword _app_url is present in the arguments passed to route_url, this value will be used as the protocol/hostname/port/leading path prefix of the generated URL. For example, using an _app_url of http://example.com:8080/foo would cause the URL http://example.com:8080/foo/fleeb/flub to be returned from this function if the expansion of the route pattern associated with the route_name expanded to /fleeb/flub.

• It is now possible to use a URL as the name argument fed to repoze.bfg.configuration.Configurator.add_static_view. When the name argument is a URL, the repoze.bfg.url.static_url API will generate join this URL (as a prefix) to a path including the static file name. This makes it more possible to put static media on a separate webserver for production, while keeping static media package-internal and served by the development webserver during development.

Documentation

• The authorization chapter of the ZODB Wiki Tutorial (docs/tutorials/bfgwiki) was changed to demonstrate authorization via a group rather than via a direct username (thanks to Alex Marandon).

• The authorization chapter of the SQLAlchemy Wiki Tutorial (docs/tutorials/bfgwiki2) was changed to demonstrate authorization via a group rather than via a direct username.

• Redirect requests for tutorial sources to http://docs.repoze.org/bfgwiki-1.3 and http://docs.repoze.org/bfgwiki2-1.3/ respectively.

• A section named Custom Route Predicates was added to the URL Dispatch narrative chapter.

• The Static Resources chapter has been updated to mention using static_url to generate URLs to external webservers.

Internal

• Removed repoze.bfg.static.StaticURLFactory in favor of a new abstraction revolving around the (still-internal) repoze.bfg.static.StaticURLInfo helper class.

Paster Templates

• The bfg_alchemy and bfg_routesalchemy templates no longer register a handle_teardown event listener which calls DBSession.remove. This was found by Chris Withers to be unnecessary.

Documentation

• The “bfgwiki2” (URL dispatch wiki) tutorial code and documentation was changed to remove the handle_teardown event listener which calls DBSession.remove.

• Any mention of the handle_teardown event listener as used by the paster templates was removed from the URL Dispatch narrative chapter.

• A section entitled Detecting Available Languages was added to the i18n narrative docs chapter.

Features

• A locale negotiator no longer needs to be registered explicitly. The default locale negotiator at repoze.bfg.i18n.default_locale_negotiator is now used unconditionally as… um, the default locale negotiator.

• The default locale negotiator has become more complex.

  • First, the negotiator looks for the _LOCALE_ attribute of the request object (possibly set by a view or an event listener).

  • Then it looks for the request.params['_LOCALE_'] value.

  • Then it looks for the request.cookies['_LOCALE_'] value.

Backwards Incompatibilities

• The default locale negotiator now looks for the parameter named _LOCALE_ rather than a parameter named locale in request.params.

Behavior Changes

• A locale negotiator may now return None, signifying that the default locale should be used.

Documentation

• Documentation concerning locale negotiation in the Internationalizationa and Localization chapter was updated.

• Expanded portion of i18n narrative chapter docs which discuss working with gettext files.

Features

• Added “exception views”. When you use an exception (anything that inherits from the Python Exception builtin) as view context argument, e.g.:

  from repoze.bfg.view import bfg_view
  from repoze.bfg.exceptions import NotFound
  from webob.exc import HTTPNotFound
  
  @bfg_view(context=NotFound)
  def notfound_view(request):
      return HTTPNotFound()

  For the above example, when the repoze.bfg.exceptions.NotFound exception is raised by any view or any root factory, the notfound_view view callable will be invoked and its response returned.

  Other normal view predicates can also be used in combination with an exception view registration:

  from repoze.bfg.view import bfg_view
  from repoze.bfg.exceptions import NotFound
  from webob.exc import HTTPNotFound
  
  @bfg_view(context=NotFound, route_name='home')
  def notfound_view(request):
      return HTTPNotFound()

  The above exception view names the route_name of home, meaning that it will only be called when the route matched has a name of home. You can therefore have more than one exception view for any given exception in the system: the “most specific” one will be called when the set of request circumstances which match the view registration. The only predicate that cannot be not be used successfully is name. The name used to look up an exception view is always the empty string.

  Existing (pre-1.3) normal views registered against objects inheriting from Exception will continue to work. Exception views used for user-defined exceptions and system exceptions used as contexts will also work.

  The feature can be used with any view registration mechanism (@bfg_view decorator, ZCML, or imperative config.add_view styles).

  This feature was kindly contributed by Andrey Popp.

• Use “Venusian” (http://docs.repoze.org/venusian) to perform bfg_view decorator scanning rather than relying on a BFG-internal decorator scanner. (Truth be told, Venusian is really just a generalization of the BFG-internal decorator scanner).

• Internationalization and localization features as documented in the narrative documentation chapter entitled Internationalization and Localization.

• A new deployment setting named default_locale_name was added. If this string is present as a Paster .ini file option, it will be considered the default locale name. The default locale name is used during locale-related operations such as language translation.

• It is now possible to turn on Chameleon template “debugging mode” for all Chameleon BFG templates by setting a BFG-related Paster .ini file setting named debug_templates. The exceptions raised by Chameleon templates when a rendering fails are sometimes less than helpful. debug_templates allows you to configure your application development environment so that exceptions generated by Chameleon during template compilation and execution will contain more helpful debugging information. This mode is on by default in all new projects.

• Add a new method of the Configurator named derive_view which can be used to generate a BFG view callable from a user-supplied function, instance, or class. This useful for external framework and plugin authors wishing to wrap callables supplied by their users which follow the same calling conventions and response conventions as objects that can be supplied directly to BFG as a view callable. See the derive_view method in the repoze.bfg.configuration.Configurator docs.

ZCML

• Add a translationdir ZCML directive to support localization.

• Add a localenegotiator ZCML directive to support localization.

Deprecations

• The exception views feature replaces the need for the set_notfound_view and set_forbidden_view methods of the Configurator as well as the notfound and forbidden ZCML directives. Those methods and directives will continue to work for the foreseeable future, but they are deprecated in the documentation.

Dependencies

• A new install-time dependency on the venusian distribution was added.

• A new install-time dependency on the translationstring distribution was added.

• Chameleon 1.2.3 or better is now required (internationalization and per-template debug settings).

Internal

• View registrations and lookups are now done with three “requires” arguments instead of two to accomodate orthogonality of exception views.

• The repoze.bfg.interfaces.IForbiddenView and repoze.bfg.interfaces.INotFoundView interfaces were removed; they weren’t APIs and they became vestigial with the addition of exception views.

• Remove repoze.bfg.compat.pkgutil_26.py and import alias repoze.bfg.compat.walk_packages. These were only required by internal scanning machinery; Venusian replaced the internal scanning machinery, so these are no longer required.

Documentation

• Exception view documentation was added to the Hooks narrative chapter.

• A new narrative chapter entitled Internationalization and Localization was added.

• The “Environment Variables and ini File Settings” chapter was changed: documentation about the default_locale_name setting was added.

• A new API chapter for the repoze.bfg.i18n module was added.

• Documentation for the new translationdir and localenegotiator ZCML directives were added.

• A section was added to the Templates chapter entitled “Nicer Exceptions in Templates” describing the result of setting debug_templates = true.

Paster Templates

• All paster templates now create a setup.cfg which includes commands related to nose testing and Babel message catalog extraction/compilation.

• A default_locale_name = en setting was added to each existing paster template.

• A debug_templates = true setting was added to each existing paster template.

Licensing

• The Edgewall (BSD) license was added to the LICENSES.txt file, as some code in the repoze.bfg.i18n derives from Babel source.