CHANGES.txt

Next Release
============

Features
--------

- Add ``pdistreport`` script, which prints the Python version in use, the
  Pyramid version in use, and the version number and location of all Python
  distributions currently installed.

- Add the ability to invert the result of any view, route, or subscriber
  predicate using the ``not_`` class.  For example::

     from pyramid.config import not_

     @view_config(route_name='myroute', request_method=not_('POST'))
     def myview(request): ...

  The above example will ensure that the view is called if the request method
  is not POST (at least if no other view is more specific).

  The :class:`pyramid.config.not_` class can be used against any value that is
  a predicate value passed in any of these contexts:

  - ``pyramid.config.Configurator.add_view``

  - ``pyramid.config.Configurator.add_route``

  - ``pyramid.config.Configurator.add_subscriber``

  - ``pyramid.view.view_config``

  - ``pyramid.events.subscriber``

- ``scripts/prequest.py``: add support for submitting ``PUT`` and ``PATCH``
  requests.  See https://github.com/Pylons/pyramid/pull/1033.  add support for
  submitting ``OPTIONS`` and ``PROPFIND`` requests, and  allow users to specify
  basic authentication credentials in the request via a ``--login`` argument to
  the script.  See https://github.com/Pylons/pyramid/pull/1039.

- ``ACLAuthorizationPolicy`` supports ``__acl__`` as a callable. This
  removes the ambiguity between the potential ``AttributeError`` that would
  be raised on the ``context`` when the property was not defined and the
  ``AttributeError`` that could be raised from any user-defined code within
  a dynamic property. It is recommended to define a dynamic ACL as a callable
  to avoid this ambiguity. See https://github.com/Pylons/pyramid/issues/735.

- Allow a protocol-relative URL (e.g. ``//example.com/images``) to be passed to
  ``pyramid.config.Configurator.add_static_view``. This allows
  externally-hosted static URLs to be generated based on the current protocol.

- The ``AuthTktAuthenticationPolicy`` has a new ``parent_domain`` option to
  set the authentication cookie as a wildcard cookie on the parent domain. This
  is useful if you have multiple sites sharing the same domain.

- The ``AuthTktAuthenticationPolicy`` now supports IPv6 addresses when using
  the ``include_ip=True`` option. This is possibly incompatible with
  alternative ``auth_tkt`` implementations, as the specification does not
  define how to properly handle IPv6. See
  https://github.com/Pylons/pyramid/issues/831.

- Make it possible to use variable arguments via
  ``pyramid.paster.get_appsettings``. This also allowed the generated
  ``initialize_db`` script from the ``alchemy`` scaffold to grow support
  for options in the form ``a=1 b=2`` so you can fill in
  values in a parameterized ``.ini`` file, e.g.
  ``initialize_myapp_db etc/development.ini a=1 b=2``.
  See https://github.com/Pylons/pyramid/pull/911

- The ``request.session.check_csrf_token()`` method and the ``check_csrf`` view
  predicate now take into account the value of the HTTP header named
  ``X-CSRF-Token`` (as well as the ``csrf_token`` form parameter, which they
  always did).  The header is tried when the form parameter does not exist.

- View lookup will now search for valid views based on the inheritance
  hierarchy of the context. It tries to find views based on the most
  specific context first, and upon predicate failure, will move up the
  inheritance chain to test views found by the super-type of the context.
  In the past, only the most specific type containing views would be checked
  and if no matching view could be found then a PredicateMismatch would be
  raised. Now predicate mismatches don't hide valid views registered on
  super-types. Here's an example that now works:

  .. code-block:: python

     class IResource(Interface):

         ...

     @view_config(context=IResource)
     def get(context, request):

         ...

     @view_config(context=IResource, request_method='POST')
     def post(context, request):

         ...

     @view_config(context=IResource, request_method='DELETE')
     def delete(context, request):

         ...

     @implementor(IResource)
     class MyResource:

         ...

     @view_config(context=MyResource, request_method='POST')
     def override_post(context, request):

         ...

  Previously the override_post view registration would hide the get
  and delete views in the context of MyResource -- leading to a
  predicate mismatch error when trying to use GET or DELETE
  methods. Now the views are found and no predicate mismatch is
  raised.
  See https://github.com/Pylons/pyramid/pull/786 and
  https://github.com/Pylons/pyramid/pull/1004 and
  https://github.com/Pylons/pyramid/pull/1046

- The ``pserve`` command now takes a ``-v`` (or ``--verbose``) flag and a
  ``-q`` (or ``--quiet``) flag.  Output from running ``pserve`` can be
  controlled using these flags.  ``-v`` can be specified multiple times to
  increase verbosity.  ``-q`` sets verbosity to ``0`` unconditionally.  The
  default verbosity level is ``1``.

- The ``alchemy`` scaffold tests now provide better coverage.  See
  https://github.com/Pylons/pyramid/pull/1029

Bug Fixes
---------

- Make the ``pyramid.config.assets.PackageOverrides`` object implement the API
  for ``__loader__`` objects specified in PEP 302.  Proxies to the
  ``__loader__`` set by the importer, if present; otherwise, raises
  ``NotImplementedError``.  This makes Pyramid static view overrides work
  properly under Python 3.3 (previously they would not).  See
  https://github.com/Pylons/pyramid/pull/1015 for more information.

- ``mako_templating``: added defensive workaround for non-importability of
  ``mako`` due to upstream ``markupsafe`` dropping Python 3.2 support.  Mako
  templating will no longer work under the combination of MarkupSafe 0.17 and
  Python 3.2 (although the combination of MarkupSafe 0.17 and Python 3.3 or any
  supported Python 2 version will work OK).

- Spaces and dots may now be in mako renderer template paths. This was
  broken when support for the new makodef syntax was added in 1.4a1.
  See https://github.com/Pylons/pyramid/issues/950

- ``pyramid.debug_authorization=true`` will now correctly print out
  ``Allowed`` for views registered with ``NO_PERMISSION_REQUIRED`` instead
  of invoking the ``permits`` method of the authorization policy.
  See https://github.com/Pylons/pyramid/issues/954

- Pyramid failed to install on some systems due to being packaged with
  some test files containing higher order characters in their names. These
  files have now been removed. See
  https://github.com/Pylons/pyramid/issues/981

- ``pyramid.testing.DummyResource`` didn't define ``__bool__``, so code under
  Python 3 would use ``__len__`` to find truthiness; this usually caused an
  instance of DummyResource to be "falsy" instead of "truthy".  See
  https://github.com/Pylons/pyramid/pull/1032

- The ``alchemy`` scaffold would break when the database was MySQL during
  tables creation.  See https://github.com/Pylons/pyramid/pull/1049

1.4 (2012-12-18)
================

Docs
----

- Fix functional tests in the ZODB tutorial

1.4b3 (2012-12-10)
==================

- Packaging release only, no code changes.  1.4b2 was a brownbag release due to
  missing directories in the tarball.

1.4b2 (2012-12-10)
==================

Docs
----

- Scaffolding is now PEP-8 compliant (at least for a brief shining moment).

- Tutorial improvements.

Backwards Incompatibilities
---------------------------

- Modified the ``_depth`` argument to ``pyramid.view.view_config`` to accept
  a value relative to the invocation of ``view_config`` itself. Thus, when it
  was previously expecting a value of ``1`` or greater, to reflect that
  the caller of ``view_config`` is 1 stack frame away from ``venusian.attach``,
  this implementation detail is now hidden.

- Modified the ``_backframes`` argument to ``pyramid.util.action_method`` in a
  similar way to the changes described to ``_depth`` above.  This argument
  remains undocumented, but might be used in the wild by some insane person.

1.4b1 (2012-11-21)
==================

Features
--------

- Small microspeed enhancement which anticipates that a
  ``pyramid.response.Response`` object is likely to be returned from a view.
  Some code is shortcut if the class of the object returned by a view is this
  class.  A similar microoptimization was done to
  ``pyramid.request.Request.is_response``.

- Make it possible to use variable arguments on ``p*`` commands (``pserve``,
  ``pshell``, ``pviews``, etc) in the form ``a=1 b=2`` so you can fill in
  values in parameterized ``.ini`` file, e.g. ``pshell etc/development.ini
  http_port=8080``.  See https://github.com/Pylons/pyramid/pull/714

- A somewhat advanced and obscure feature of Pyramid event handlers is their
  ability to handle "multi-interface" notifications.  These notifications have
  traditionally presented multiple objects to the subscriber callable.  For
  instance, if an event was sent by code like this::

     registry.notify(event, context)

  In the past, in order to catch such an event, you were obligated to write and
  register an event subscriber that mentioned both the event and the context in
  its argument list::

     @subscriber([SomeEvent, SomeContextType])
     def asubscriber(event, context):
         pass

  In many subscriber callables registered this way, it was common for the logic
  in the subscriber callable to completely ignore the second and following
  arguments (e.g. ``context`` in the above example might be ignored), because
  they usually existed as attributes of the event anyway.  You could usually
  get the same value by doing ``event.context`` or similar.

  The fact that you needed to put an extra argument which you usually ignored
  in the subscriber callable body was only a minor annoyance until we added
  "subscriber predicates", used to narrow the set of circumstances under which
  a subscriber will be executed, in a prior 1.4 alpha release.  Once those were
  added, the annoyance was escalated, because subscriber predicates needed to
  accept the same argument list and arity as the subscriber callables that they
  were configured against.  So, for example, if you had these two subscriber
  registrations in your code::

     @subscriber([SomeEvent, SomeContextType])
     def asubscriber(event, context):
         pass

     @subscriber(SomeOtherEvent)
     def asubscriber(event):
         pass
 
  And you wanted to use a subscriber predicate::

     @subscriber([SomeEvent, SomeContextType], mypredicate=True)
     def asubscriber1(event, context):
         pass

     @subscriber(SomeOtherEvent, mypredicate=True)
     def asubscriber2(event):
         pass

  If an existing ``mypredicate`` subscriber predicate had been written in such
  a way that it accepted only one argument in its ``__call__``, you could not
  use it against a subscription which named more than one interface in its
  subscriber interface list.  Similarly, if you had written a subscriber
  predicate that accepted two arguments, you couldn't use it against a
  registration that named only a single interface type.

  For example, if you created this predicate::

    class MyPredicate(object):
        # portions elided...
        def __call__(self, event):
            return self.val == event.context.foo

  It would not work against a multi-interface-registered subscription, so in
  the above example, when you attempted to use it against ``asubscriber1``, it
  would fail at runtime with a TypeError, claiming something was attempting to
  call it with too many arguments.

  To hack around this limitation, you were obligated to design the
  ``mypredicate`` predicate to expect to receive in its ``__call__`` either a
  single ``event`` argument (a SomeOtherEvent object) *or* a pair of arguments
  (a SomeEvent object and a SomeContextType object), presumably by doing
  something like this::

    class MyPredicate(object):
        # portions elided...
        def __call__(self, event, context=None):
            return self.val == event.context.foo

  This was confusing and bad.

  In order to allow people to ignore unused arguments to subscriber callables
  and to normalize the relationship between event subscribers and subscriber
  predicates, we now allow both subscribers and subscriber predicates to accept
  only a single ``event`` argument even if they've been subscribed for
  notifications that involve multiple interfaces.  Subscribers and subscriber
  predicates that accept only one argument will receive the first object passed
  to ``notify``; this is typically (but not always) the event object.  The
  other objects involved in the subscription lookup will be discarded.  You can
  now write an event subscriber that accepts only ``event`` even if it
  subscribes to multiple interfaces::

     @subscriber([SomeEvent, SomeContextType])
     def asubscriber(event):
         # this will work!

  This prevents you from needing to match the subscriber callable parameters to
  the subscription type unnecessarily, especially when you don't make use of
  any argument in your subscribers except for the event object itself.

  Note, however, that if the event object is not the first
  object in the call to ``notify``, you'll run into trouble.  For example, if
  notify is called with the context argument first::

     registry.notify(context, event)

  You won't be able to take advantage of the event-only feature.  It will
  "work", but the object received by your event handler won't be the event
  object, it will be the context object, which won't be very useful::

     @subscriber([SomeContextType, SomeEvent])
     def asubscriber(event):
         # bzzt! you'll be getting the context here as ``event``, and it'll 
         # be useless

  Existing multiple-argument subscribers continue to work without issue, so you
  should continue use those if your system notifies using multiple interfaces
  and the first interface is not the event interface.  For example::

     @subscriber([SomeContextType, SomeEvent])
     def asubscriber(context, event):
         # this will still work!

  The event-only feature makes it possible to use a subscriber predicate that
  accepts only a request argument within both multiple-interface subscriber
  registrations and single-interface subscriber registrations.  You needn't
  make slightly different variations of predicates depending on the
  subscription type arguments.  Instead, just write all your subscriber
  predicates so they only accept ``event`` in their ``__call__`` and they'll be
  useful across all registrations for subscriptions that use an event as their
  first argument, even ones which accept more than just ``event``.

  However, the same caveat applies to predicates as to subscriber callables: if
  you're subscribing to a multi-interface event, and the first interface is not
  the event interface, the predicate won't work properly.  In such a case,
  you'll need to match the predicate ``__call__`` argument ordering and
  composition to the ordering of the interfaces.  For example, if the
  registration for the subscription uses ``[SomeContext, SomeEvent]``, you'll
  need to reflect that in the ordering of the parameters of the predicate's
  ``__call__`` method::

        def __call__(self, context, event):
            return event.request.path.startswith(self.val)

  tl;dr: 1) When using multi-interface subscriptions, always use the event type
  as the first subscription registration argument and 2) When 1 is true, use
  only ``event`` in your subscriber and subscriber predicate parameter lists,
  no matter how many interfaces the subscriber is notified with.  This
  combination will result in the maximum amount of reusability of subscriber
  predicates and the least amount of thought on your part.  Drink responsibly.

Bug Fixes
---------

- A failure when trying to locate the attribute ``__text__`` on route and view
  predicates existed when the ``debug_routematch`` setting was true or when the
  ``pviews`` command was used. See https://github.com/Pylons/pyramid/pull/727

Documentation
-------------

- Sync up tutorial source files with the files that are rendered by the
  scaffold that each uses.

1.4a4 (2012-11-14)
==================

Features
--------

- ``pyramid.authentication.AuthTktAuthenticationPolicy`` has been updated to
  support newer hashing algorithms such as ``sha512``. Existing applications
  should consider updating if possible for improved security over the default
  md5 hashing.

- Added an ``effective_principals`` route and view predicate.

- Do not allow the userid returned from the ``authenticated_userid`` or the
  userid that is one of the list of principals returned by
  ``effective_principals`` to be either of the strings ``system.Everyone`` or
  ``system.Authenticated`` when any of the built-in authorization policies that
  live in ``pyramid.authentication`` are in use.  These two strings are
  reserved for internal usage by Pyramid and they will not be accepted as valid
  userids.

- Slightly better debug logging from
  ``pyramid.authentication.RepozeWho1AuthenticationPolicy``.

- ``pyramid.security.view_execution_permitted`` used to return ``True`` if no
  view could be found. It now raises a ``TypeError`` exception in that case, as
  it doesn't make sense to assert that a nonexistent view is
  execution-permitted. See https://github.com/Pylons/pyramid/issues/299.

- Allow a ``_depth`` argument to ``pyramid.view.view_config``, which will
  permit limited composition reuse of the decorator by other software that
  wants to provide custom decorators that are much like view_config.

- Allow an iterable of decorators to be passed to
  ``pyramid.config.Configurator.add_view``. This allows views to be wrapped
  by more than one decorator without requiring combining the decorators
  yourself.

Bug Fixes
---------

- In the past if a renderer returned ``None``, the body of the resulting
  response would be set explicitly to the empty string.  Instead, now, the body
  is left unchanged, which allows the renderer to set a body itself by using
  e.g. ``request.response.body = b'foo'``.  The body set by the renderer will
  be unmolested on the way out.  See
  https://github.com/Pylons/pyramid/issues/709

- In uncommon cases, the ``pyramid_excview_tween_factory`` might have
  inadvertently raised a ``KeyError`` looking for ``request_iface`` as an
  attribute of the request.  It no longer fails in this case.  See
  https://github.com/Pylons/pyramid/issues/700

- Be more tolerant of potential error conditions in ``match_param`` and
  ``physical_path`` predicate implementations; instead of raising an exception,
  return False.

- ``pyramid.view.render_view`` was not functioning properly under Python 3.x
  due to a byte/unicode discrepancy. See
  https://github.com/Pylons/pyramid/issues/721

Deprecations
------------

- ``pyramid.authentication.AuthTktAuthenticationPolicy`` will emit a warning if
  an application is using the policy without explicitly passing a ``hashalg``
  argument. This is because the default is "md5" which is considered
  theoretically subject to collision attacks. If you really want "md5" then you
  must specify it explicitly to get rid of the warning.

Documentation
-------------

- All of the tutorials that use
  ``pyramid.authentication.AuthTktAuthenticationPolicy`` now explicitly pass
  ``sha512`` as a ``hashalg`` argument.


Internals
---------

- Move ``TopologicalSorter`` from ``pyramid.config.util`` to ``pyramid.util``,
  move ``CyclicDependencyError`` from ``pyramid.config.util`` to
  ``pyramid.exceptions``, rename ``Singleton`` to ``Sentinel`` and move from
  ``pyramid.config.util`` to ``pyramid.util``; this is in an effort to
  move that stuff that may be an API one day out of ``pyramid.config.util``,
  because that package should never be imported from non-Pyramid code.
  TopologicalSorter is still not an API, but may become one.

- Get rid of shady monkeypatching of ``pyramid.request.Request`` and
  ``pyramid.response.Response`` done within the ``__init__.py`` of Pyramid.
  Webob no longer relies on this being done.  Instead, the ResponseClass
  attribute of the Pyramid Request class is assigned to the Pyramid response
  class; that's enough to satisfy WebOb and behave as it did before with the
  monkeypatching.

1.4a3 (2012-10-26)
==================

Bug Fixes
---------

- The match_param predicate's text method was fixed to sort its values.
  Part of https://github.com/Pylons/pyramid/pull/705

- 1.4a ``pyramid.scripting.prepare`` behaved differently than 1.3 series
  function of same name.  In particular, if passed a request, it would not
  set the ``registry`` attribute of the request like 1.3 did.  A symptom
  would be that passing a request to ``pyramid.paster.bootstrap`` (which uses
  the function) that did not have a ``registry`` attribute could assume that
  the registry would be attached to the request by Pyramid.  This assumption
  could be made in 1.3, but not in 1.4.  The assumption can now be made in
  1.4 too (a registry is attached to a request passed to bootstrap or
  prepare).

- When registering a view configuration that named a Chameleon ZPT renderer
  with a macro name in it (e.g. ``renderer='some/template#somemacro.pt``) as
  well as a view configuration without a macro name in it that pointed to the
  same template (e.g. ``renderer='some/template.pt'``), internal caching could
  confuse the two, and your code might have rendered one instead of the
  other.

Features
--------

- Allow multiple values to be specified to the ``request_param`` view/route
  predicate as a sequence.  Previously only a single string value was allowed.
  See https://github.com/Pylons/pyramid/pull/705

- Comments with references to documentation sections placed in scaffold
  ``.ini`` files.

- Added an HTTP Basic authentication policy
  at ``pyramid.authentication.BasicAuthAuthenticationPolicy``.

- The Configurator ``testing_securitypolicy`` method now returns the policy
  object it creates.

- The Configurator ``testing_securitypolicy`` method accepts two new
  arguments: ``remember_result`` and ``forget_result``.  If supplied, these
  values influence the result of the policy's ``remember`` and ``forget``
  methods, respectively.

- The DummySecurityPolicy created by ``testing_securitypolicy`` now sets a
  ``forgotten`` value on the policy (the value ``True``) when its ``forget``
  method is called.

- The DummySecurityPolicy created by ``testing_securitypolicy`` now sets a
  ``remembered`` value on the policy, which is the value of the ``principal``
  argument it's called with when its ``remember`` method is called.

- New ``physical_path`` view predicate.  If specified, this value should be a
  string or a tuple representing the physical traversal path of the context
  found via traversal for this predicate to match as true.  For example:
  ``physical_path='/'`` or ``physical_path='/a/b/c'`` or ``physical_path=('',
  'a', 'b', 'c')``.  This is not a path prefix match or a regex, it's a
  whole-path match.  It's useful when you want to always potentially show a
  view when some object is traversed to, but you can't be sure about what kind
  of object it will be, so you can't use the ``context`` predicate.  The
  individual path elements inbetween slash characters or in tuple elements
  should be the Unicode representation of the name of the resource and should
  not be encoded in any way.

1.4a2 (2012-09-27)
==================

Bug Fixes
---------

- When trying to determine Mako defnames and Chameleon macro names in asset
  specifications, take into account that the filename may have a hyphen in
  it.  See https://github.com/Pylons/pyramid/pull/692

Features
--------

- A new ``pyramid.session.check_csrf_token`` convenience function was added.

- A ``check_csrf`` view predicate was added.  For example, you can now do
  ``config.add_view(someview, check_csrf=True)``.  When the predicate is
  checked, if the ``csrf_token`` value in ``request.params`` matches the CSRF
  token in the request's session, the view will be permitted to execute.
  Otherwise, it will not be permitted to execute.

- Add ``Base.metadata.bind = engine`` to alchemy template, so that tables
  defined imperatively will work.

Documentation
-------------

- update wiki2 SQLA tutorial with the changes required after inserting
  ``Base.metadata.bind = engine`` into the alchemy scaffold.

1.4a1 (2012-09-16)
==================

Bug Fixes
---------

- Forward port from 1.3 branch: When no authentication policy was configured,
  a call to ``pyramid.security.effective_principals`` would unconditionally
  return the empty list.  This was incorrect, it should have unconditionally
  returned ``[Everyone]``, and now does.

- Explicit url dispatch regexes can now contain colons.
  https://github.com/Pylons/pyramid/issues/629

- On at least one 64-bit Ubuntu system under Python 3.2, using the
  ``view_config`` decorator caused a ``RuntimeError: dictionary changed size
  during iteration`` exception.  It no longer does.  See
  https://github.com/Pylons/pyramid/issues/635 for more information.

- In Mako Templates lookup, check if the uri is already adjusted and bring
  it back to an asset spec. Normally occurs with inherited templates or
  included components.
  https://github.com/Pylons/pyramid/issues/606
  https://github.com/Pylons/pyramid/issues/607

- In Mako Templates lookup, check for absolute uri (using mako directories) 
  when mixing up inheritance with asset specs.
  https://github.com/Pylons/pyramid/issues/662

- HTTP Accept headers were not being normalized causing potentially
  conflicting view registrations to go unnoticed. Two views that only
  differ in the case ('text/html' vs. 'text/HTML') will now raise an error.
  https://github.com/Pylons/pyramid/pull/620

- Forward-port from 1.3 branch: when registering multiple views with an
  ``accept`` predicate in a Pyramid application runing under Python 3, you
  might have received a ``TypeError: unorderable types: function() <
  function()`` exception.

Features
--------

- Configurator.add_directive now accepts arbitrary callables like partials or
  objects implementing ``__call__`` which dont have ``__name__`` and
  ``__doc__`` attributes.  See https://github.com/Pylons/pyramid/issues/621
  and https://github.com/Pylons/pyramid/pull/647.

- Third-party custom view, route, and subscriber predicates can now be added
  for use by view authors via
  ``pyramid.config.Configurator.add_view_predicate``,
  ``pyramid.config.Configurator.add_route_predicate`` and
  ``pyramid.config.Configurator.add_subscriber_predicate``.  So, for example,
  doing this::

     config.add_view_predicate('abc', my.package.ABCPredicate)

  Might allow a view author to do this in an application that configured that
  predicate::

     @view_config(abc=1)

  Similar features exist for ``add_route``, and ``add_subscriber``.  See
  "Adding A Third Party View, Route, or Subscriber Predicate" in the Hooks
  chapter for more information.

  Note that changes made to support the above feature now means that only
  actions registered using the same "order" can conflict with one another.
  It used to be the case that actions registered at different orders could
  potentially conflict, but to my knowledge nothing ever depended on this
  behavior (it was a bit silly).

- Custom objects can be made easily JSON-serializable in Pyramid by defining
  a ``__json__`` method on the object's class. This method should return
  values natively serializable by ``json.dumps`` (such as ints, lists,
  dictionaries, strings, and so forth).

- The JSON renderer now allows for the definition of custom type adapters to
  convert unknown objects to JSON serializations.

- As of this release, the ``request_method`` predicate, when used, will also
  imply that ``HEAD`` is implied when you use ``GET``.  For example, using
  ``@view_config(request_method='GET')`` is equivalent to using
  ``@view_config(request_method=('GET', 'HEAD'))``.  Using
  ``@view_config(request_method=('GET', 'POST')`` is equivalent to using
  ``@view_config(request_method=('GET', 'HEAD', 'POST')``.  This is because
  HEAD is a variant of GET that omits the body, and WebOb has special support
  to return an empty body when a HEAD is used.

- ``config.add_request_method`` has been introduced to support extending
  request objects with arbitrary callables. This method expands on the
  previous ``config.set_request_property`` by supporting methods as well as
  properties. This method now causes less code to be executed at
  request construction time than ``config.set_request_property`` in
  version 1.3.

- Don't add a ``?`` to URLs generated by ``request.resource_url`` if the
  ``query`` argument is provided but empty.

- Don't add a ``?`` to URLs generated by ``request.route_url`` if the
  ``_query`` argument is provided but empty.

- The static view machinery now raises (rather than returns) ``HTTPNotFound``
  and ``HTTPMovedPermanently`` exceptions, so these can be caught by the
  Not Found View (and other exception views).

- The Mako renderer now supports a def name in an asset spec.  When the def
  name is present in the asset spec, the system will render the template def
  within the template and will return the result. An example asset spec is
  ``package:path/to/template#defname.mako``. This will render the def named
  ``defname`` inside the ``template.mako`` template instead of rendering the
  entire template.  The old way of returning a tuple in the form
  ``('defname', {})`` from the view is supported for backward compatibility,

- The Chameleon ZPT renderer now accepts a macro name in an asset spec.  When
  the macro name is present in the asset spec, the system will render the
  macro listed as a ``define-macro`` and return the result instead of
  rendering the entire template.  An example asset spec:
  ``package:path/to/template#macroname.pt``.  This will render the macro
  defined as ``macroname`` within the ``template.pt`` template instead of the
  entire templae.

- When there is a predicate mismatch exception (seen when no view matches for
  a given request due to predicates not working), the exception now contains
  a textual description of the predicate which didn't match.

- An ``add_permission`` directive method was added to the Configurator.  This
  directive registers a free-standing permission introspectable into the
  Pyramid introspection system.  Frameworks built atop Pyramid can thus use
  the ``permissions`` introspectable category data to build a
  comprehensive list of permissions supported by a running system.  Before
  this method was added, permissions were already registered in this
  introspectable category as a side effect of naming them in an ``add_view``
  call, this method just makes it possible to arrange for a permission to be
  put into the ``permissions`` introspectable category without naming it
  along with an associated view.  Here's an example of usage of
  ``add_permission``::

      config = Configurator()
      config.add_permission('view')

- The ``UnencryptedCookieSessionFactoryConfig`` now accepts
  ``signed_serialize`` and ``signed_deserialize`` hooks which may be used
  to influence how the sessions are marshalled (by default this is done
  with HMAC+pickle).

- ``pyramid.testing.DummyRequest`` now supports methods supplied by the
  ``pyramid.util.InstancePropertyMixin`` class such as ``set_property``.

- Request properties and methods added via ``config.set_request_property`` or
  ``config.add_request_method`` are now available to tweens.

- Request properties and methods added via ``config.set_request_property`` or
  ``config.add_request_method`` are now available in the request object
  returned from ``pyramid.paster.bootstrap``.

- ``request.context`` of environment request during ``bootstrap`` is now the
  root object if a context isn't already set on a provided request.

- The ``pyramid.decorator.reify`` function is now an API, and was added to
  the API documentation.

- Added the ``pyramid.testing.testConfig`` context manager, which can be used
  to generate a configurator in a test, e.g. ``with testing.testConfig(...):``.

- Users can now invoke a subrequest from within view code using a new
  ``request.invoke_subrequest`` API.

Deprecations
------------

- The ``pyramid.config.Configurator.set_request_property`` has been
  documentation-deprecated.  The method remains usable but the more
  featureful ``pyramid.config.Configurator.add_request_method`` should be
  used in its place (it has all of the same capabilities but can also extend
  the request object with methods).

Backwards Incompatibilities
---------------------------

- The Pyramid router no longer adds the values ``bfg.routes.route`` or
  ``bfg.routes.matchdict`` to the request's WSGI environment dictionary.
  These values were docs-deprecated in ``repoze.bfg`` 1.0 (effectively seven
  minor releases ago).  If your code depended on these values, use
  request.matched_route and request.matchdict instead.

- It is no longer possible to pass an environ dictionary directly to
  ``pyramid.traversal.ResourceTreeTraverser.__call__`` (aka
  ``ModelGraphTraverser.__call__``).  Instead, you must pass a request
  object.  Passing an environment instead of a request has generated a
  deprecation warning since Pyramid 1.1.

- Pyramid will no longer work properly if you use the
  ``webob.request.LegacyRequest`` as a request factory.  Instances of the
  LegacyRequest class have a ``request.path_info`` which return a string.
  This Pyramid release assumes that ``request.path_info`` will
  unconditionally be Unicode.

- The functions from ``pyramid.chameleon_zpt`` and ``pyramid.chameleon_text``
  named ``get_renderer``, ``get_template``, ``render_template``, and
  ``render_template_to_response`` have been removed.  These have issued a
  deprecation warning upon import since Pyramid 1.0.  Use
  ``pyramid.renderers.get_renderer()``,
  ``pyramid.renderers.get_renderer().implementation()``,
  ``pyramid.renderers.render()`` or ``pyramid.renderers.render_to_response``
  respectively instead of these functions.

- The ``pyramid.configuration`` module was removed.  It had been deprecated
  since Pyramid 1.0 and printed a deprecation warning upon its use.  Use
  ``pyramid.config`` instead.

- The ``pyramid.paster.PyramidTemplate`` API was removed.  It had been
  deprecated since Pyramid 1.1 and issued a warning on import.  If your code
  depended on this, adjust your code to import
  ``pyramid.scaffolds.PyramidTemplate`` instead.

- The ``pyramid.settings.get_settings()`` API was removed.  It had been
  printing a deprecation warning since Pyramid 1.0.  If your code depended on
  this API, use ``pyramid.threadlocal.get_current_registry().settings``
  instead or use the ``settings`` attribute of the registry available from
  the request (``request.registry.settings``).

- These APIs from the ``pyramid.testing`` module were removed.  They have
  been printing deprecation warnings since Pyramid 1.0:

  * ``registerDummySecurityPolicy``, use
    ``pyramid.config.Configurator.testing_securitypolicy`` instead.

  * ``registerResources`` (aka ``registerModels``, use
    ``pyramid.config.Configurator.testing_resources`` instead.

  * ``registerEventListener``, use
    ``pyramid.config.Configurator.testing_add_subscriber`` instead.

  * ``registerTemplateRenderer`` (aka `registerDummyRenderer``), use
    ``pyramid.config.Configurator.testing_add_template`` instead.

  * ``registerView``, use ``pyramid.config.Configurator.add_view`` instead.

  * ``registerUtility``, use
    ``pyramid.config.Configurator.registry.registerUtility`` instead.

  * ``registerAdapter``, use
    ``pyramid.config.Configurator.registry.registerAdapter`` instead.

  * ``registerSubscriber``, use 
    ``pyramid.config.Configurator.add_subscriber`` instead.

  * ``registerRoute``, use 
    ``pyramid.config.Configurator.add_route`` instead.

  * ``registerSettings``, use 
    ``pyramid.config.Configurator.add_settings`` instead.

- In Pyramid 1.3 and previous, the ``__call__`` method of a Response object
  was invoked before any finished callbacks were executed.  As of this
  release, the ``__call__`` method of a Response object is invoked *after*
  finished callbacks are executed.  This is in support of the
  ``request.invoke_subrequest`` feature.

Documentation
-------------

- Added an "Upgrading Pyramid" chapter to the narrative documentation.  It
  describes how to cope with deprecations and removals of Pyramid APIs and
  how to show Pyramid-generated deprecation warnings while running tests and
  while running a server.

- Added a "Invoking a Subrequest" chapter to the documentation.  It describes
  how to use the new ``request.invoke_subrequest`` API.

Dependencies
------------

- Pyramid now requires WebOb 1.2b3+ (the prior Pyramid release only relied on
  1.2dev+).  This is to ensure that we obtain a version of WebOb that returns
  ``request.path_info`` as text.