What's New in Pyramid 1.2 ========================= This article explains the new features in :app:`Pyramid` version 1.2 as compared to its predecessor, :app:`Pyramid` 1.1. It also documents backwards incompatibilities between the two versions and deprecations added to Pyramid 1.2, as well as software dependency changes and notable documentation additions. Major Feature Additions ----------------------- The major feature additions in Pyramid 1.2 follow. Debug Toolbar ~~~~~~~~~~~~~ The scaffolding packages that come with Pyramid now include a debug toolbar component which can be used to interactively debug an application. See :ref:`debug_toolbar` for more information. ``route_prefix`` Argument to include ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The :meth:`pyramid.config.Configurator.include` method now accepts a ``route_prefix`` argument. This argument allows you to compose URL dispatch applications together from disparate packages. See :ref:`route_prefix` for more information. Tweens ~~~~~~ A :term:`tween` is used to wrap the Pyramid router's primary request handling function. This is a feature that can be used by Pyramid framework extensions, to provide, for example, view timing support and can provide a convenient place to hang bookkeeping code. Tweens are a little like :term:`WSGI` :term:`middleware`, but have access to Pyramid functionality such as renderers and a full-featured request object. To support this feature, a new configurator directive exists named :meth:`pyramid.config.Configurator.add_tween`. This directive adds a "tween". Tweens are further described in :ref:`registering_tweens`. A new paster command now exists: ``paster ptweens``. This command prints the current tween configuration for an application. See the section entitled :ref:`displaying_tweens` for more info. Scaffolding Changes ~~~~~~~~~~~~~~~~~~~ - All scaffolds now use the ``pyramid_tm`` package rather than the ``repoze.tm2`` :term:`middleware` to manage transaction management. - The ZODB scaffold now uses the ``pyramid_zodbconn`` package rather than the ``repoze.zodbconn`` package to provide ZODB integration. - All scaffolds now use the ``pyramid_debugtoolbar`` package rather than the ``WebError`` package to provide interactive debugging features. - Projects created via a scaffold no longer depend on the ``WebError`` package at all; configuration in the ``production.ini`` file which used to require its ``error_catcher`` :term:`middleware` has been removed. Configuring error catching / email sending is now the domain of the ``pyramid_exclog`` package (see https://docs.pylonsproject.org/projects/pyramid_exclog/en/latest/). - All scaffolds now send the ``cache_max_age`` parameter to the ``add_static_view`` method. Minor Feature Additions ----------------------- - The ``[pshell]`` section in an ini configuration file now treats a ``setup`` key as a dotted name that points to a callable that is passed the bootstrap environment. It can mutate the environment as necessary during a ``paster pshell`` session. This feature is described in :ref:`writing_a_script`. - A new configuration setting named ``pyramid.includes`` is now available. It is described in :ref:`including_packages`. - Added a :data:`pyramid.security.NO_PERMISSION_REQUIRED` constant for use in ``permission=`` statements to view configuration. This constant has a value of the string ``__no_permission_required__``. This string value was previously referred to in documentation; now the documentation uses the constant. - Added a decorator-based way to configure a response adapter: :class:`pyramid.response.response_adapter`. This decorator has the same use as :meth:`pyramid.config.Configurator.add_response_adapter` but it's declarative. - The :class:`pyramid.events.BeforeRender` event now has an attribute named ``rendering_val``. This can be used to introspect the value returned by a view in a BeforeRender subscriber. - The Pyramid debug logger now uses the standard logging configuration (usually set up by Paste as part of startup). This means that output from e.g. ``debug_notfound``, ``debug_authorization``, etc. will go to the normal logging channels. The logger name of the debug logger will be the package name of the *caller* of the Configurator's constructor. - A new attribute is available on request objects: ``exc_info``. Its value will be ``None`` until an exception is caught by the Pyramid router, after which it will be the result of ``sys.exc_info()``. - :class:`pyramid.testing.DummyRequest` now implements the ``add_finished_callback`` and ``add_response_callback`` methods implemented by :class:`pyramid.request.Request`. - New methods of the :class:`pyramid.config.Configurator` class: :meth:`~pyramid.config.Configurator.set_authentication_policy` and :meth:`~pyramid.config.Configurator.set_authorization_policy`. These are meant to be consumed mostly by add-on authors who wish to offer packages which register security policies. - New Configurator method: :meth:`pyramid.config.Configurator.set_root_factory`, which can set the root factory after the Configurator has been constructed. - Pyramid no longer eagerly commits some default configuration statements at :term:`Configurator` construction time, which permits values passed in as constructor arguments (e.g. ``authentication_policy`` and ``authorization_policy``) to override the same settings obtained via the :meth:`pyramid.config.Configurator.include` method. - Better Mako rendering exceptions; the template line which caused the error is now shown when a Mako rendering raises an exception. - New request methods: :meth:`~pyramid.request.Request.current_route_url`, :meth:`~pyramid.request.Request.current_route_path`, and :meth:`~pyramid.request.Request.static_path`. - New functions in the :mod:`pyramid.url` module: :func:`~pyramid.url.current_route_path` and :func:`~pyramid.url.static_path`. - The :meth:`pyramid.request.Request.static_url` API (and its brethren :meth:`pyramid.request.Request.static_path`, :func:`pyramid.url.static_url`, and :func:`pyramid.url.static_path`) now accept an absolute filename as a "path" argument. This will generate a URL to an asset as long as the filename is in a directory which was previously registered as a static view. Previously, trying to generate a URL to an asset using an absolute file path would raise a ValueError. - The :class:`~pyramid.authentication.RemoteUserAuthenticationPolicy`, :class:`~pyramid.authentication.AuthTktAuthenticationPolicy`, and :class:`~pyramid.authentication.SessionAuthenticationPolicy` constructors now accept an additional keyword argument named ``debug``. By default, this keyword argument is ``False``. When it is ``True``, debug information will be sent to the Pyramid debug logger (usually on stderr) when the ``authenticated_userid`` or ``effective_principals`` method is called on any of these policies. The output produced can be useful when trying to diagnose authentication-related problems. - New view predicate: ``match_param``. Example: a view added via ``config.add_view(aview, match_param='action=edit')`` will be called only when the ``request.matchdict`` has a value inside it named ``action`` with a value of ``edit``. - Support an ``onerror`` keyword argument to :meth:`pyramid.config.Configurator.scan`. This argument is passed to :meth:`venusian.Scanner.scan` to influence error behavior when an exception is raised during scanning. - The ``request_method`` predicate argument to :meth:`pyramid.config.Configurator.add_view` and :meth:`pyramid.config.Configurator.add_route` is now permitted to be a tuple of HTTP method names. Previously it was restricted to being a string representing a single HTTP method name. - Undeprecated ``pyramid.traversal.find_model``, ``pyramid.traversal.model_path``, ``pyramid.traversal.model_path_tuple``, and ``pyramid.url.model_url``, which were all deprecated in Pyramid 1.0. There's just not much cost to keeping them around forever as aliases to their renamed ``resource_*`` prefixed functions. - Undeprecated ``pyramid.view.bfg_view``, which was deprecated in Pyramid 1.0. This is a low-cost alias to ``pyramid.view.view_config`` which we'll just keep around forever. - Route pattern replacement marker names can now begin with an underscore. See https://github.com/Pylons/pyramid/issues/276. Deprecations ------------ - All Pyramid-related :term:`deployment settings` (e.g. ``debug_all``, ``debug_notfound``) are now meant to be prefixed with the prefix ``pyramid.``. For example: ``debug_all`` -> ``pyramid.debug_all``. The old non-prefixed settings will continue to work indefinitely but supplying them may print a deprecation warning. All scaffolds and tutorials have been changed to use prefixed settings. - The :term:`deployment settings` dictionary now raises a deprecation warning when you attempt to access its values via ``__getattr__`` instead of via ``__getitem__``. Backwards Incompatibilities --------------------------- - If a string is passed as the ``debug_logger`` parameter to a :term:`Configurator`, that string is considered to be the name of a global Python logger rather than a dotted name to an instance of a logger. - The :meth:`pyramid.config.Configurator.include` method now accepts only a single ``callable`` argument. A *sequence* of callables used to be permitted. If you are passing more than one ``callable`` to :meth:`pyramid.config.Configurator.include`, it will break. You now must now instead make a separate call to the method for each callable. - It may be necessary to more strictly order configuration route and view statements when using an "autocommitting" :term:`Configurator`. In the past, it was possible to add a view which named a route name before adding a route with that name when you used an autocommitting configurator. For example: .. code-block:: python config = Configurator(autocommit=True) config.add_view('my.pkg.someview', route_name='foo') config.add_route('foo', '/foo') The above will raise an exception when the view attempts to add itself. Now you must add the route before adding the view: .. code-block:: python config = Configurator(autocommit=True) config.add_route('foo', '/foo') config.add_view('my.pkg.someview', route_name='foo') This won't effect "normal" users, only people who have legacy BFG codebases that used an autocommitting configurator and possibly tests that use the configurator API (the configurator returned by :func:`pyramid.testing.setUp` is an autocommitting configurator). The right way to get around this is to use a default non-autocommitting configurator, which does not have these directive ordering requirements: .. code-block:: python config = Configurator() config.add_view('my.pkg.someview', route_name='foo') config.add_route('foo', '/foo') The above will work fine. - The :meth:`pyramid.config.Configurator.add_route` directive no longer returns a route object. This change was required to make route vs. view configuration processing work properly. Behavior Differences -------------------- - An ETag header is no longer set when serving a static file. A Last-Modified header is set instead. - Static file serving no longer supports the ``wsgi.file_wrapper`` extension. - Instead of returning a ``403 Forbidden`` error when a static file is served that cannot be accessed by the Pyramid process' user due to file permissions, an IOError (or similar) will be raised. Documentation Enhancements -------------------------- - Narrative and API documentation which used the ``route_url``, ``route_path``, ``resource_url``, ``static_url``, and ``current_route_url`` functions in the :mod:`pyramid.url` package have now been changed to use eponymous methods of the request instead. - Added a section entitled :ref:`route_prefix` to the "URL Dispatch" narrative documentation chapter. - Added a new module to the API docs: :mod:`pyramid.tweens`. - Added a :ref:`registering_tweens` section to the "Hooks" narrative chapter. - Added a :ref:`displaying_tweens` section to the "Command-Line Pyramid" narrative chapter. - Added documentation for :ref:`explicit_tween_config` and :ref:`including_packages` to the "Environment Variables and ``.ini`` Files Settings" chapter. - Added a :ref:`logging_chapter` chapter to the narrative docs. - All tutorials now use - The ``route_url``, ``route_path``, ``resource_url``, ``static_url``, and ``current_route_url`` methods of the :class:`pyramid.request.Request` rather than the function variants imported from ``pyramid.url``. - The ZODB wiki tutorial now uses the ``pyramid_zodbconn`` package rather than the ``repoze.zodbconn`` package to provide ZODB integration. - Added :ref:`what_makes_pyramid_unique` to the Introduction narrative chapter. Dependency Changes ------------------ - Pyramid now relies on PasteScript >= 1.7.4. This version contains a feature important for allowing flexible logging configuration. - Pyramid now requires Venusian 1.0a1 or better to support the ``onerror`` keyword argument to :meth:`pyramid.config.Configurator.scan`. - The ``zope.configuration`` package is no longer a dependency.