Features

--------

- New view predicate: match_val.  The ``match_val`` value represents
  the presence of a value in the structure added to the request named
  ``matchdict`` during URL dispatch representing the match values from
  the route pattern (e.g. if the route pattern has ``:foo`` in it, and
  the route matches, a key will exist in the matchdict named ``foo``).
  Like all other view predicates, this feature is exposed via the
  ``bfg_view`` API, the Configurator ``add_view`` API, and the ZCML
  ``view`` directive.

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

- API documentation for the ``add_view`` method of the configurator
  changed to include ``match_val``.

- ZCML documentation for ``view`` ZCML directive changed to include
  ``match_val``.

- The ``Views`` narrative chapter now contains a description of the
  ``match_val`` predicate.

Bug Fixes
---------

- The ``header`` predicate (when used as either a view predicate or a
  route predicate) had a problem when specified with a name/regex
  pair.  When the header did not exist in the headers dictionary, the
  regex match could be fed ``None``, causing it to throw a
  ``TypeError: expected string or buffer`` exception.  Now, the
  predicate returns False as intended.

Internal
--------

- Remove ``repoze.bfg.configuration.isclass`` function in favor of
  using ``inspect.isclass``.

1 files changed, 27 insertions, 0 deletions

diff --git a/docs/narr/views.rst b/docs/narr/views.rst
index eebaa63de..9b7d6b2dd 100644
--- a/docs/narr/views.rst
+++ b/docs/narr/views.rst
@@ -1358,6 +1358,33 @@ Predicate Arguments
   taken into consideration when deciding whether or not to invoke the
   associated view callable.
 
+``match_val``
+
+  This value represents :term:`URL dispatch` ``request.matchdict``
+  name or a matchdict name/value pair.  ``request.matchdict`` is a
+  dictionary representing the match values from the route pattern
+  (e.g. if the route pattern has ``:foo`` in it, and the route
+  matches, a key will exist in the matchdict named ``foo``).
+
+  If ``match_val`` is specified, it must be the name of a key presumed
+  to be present in the ``matchdict`` or a ``key:regex`` pair.
+
+  If ``match_val`` is specified without a colon in it
+  (e.g. ``action``), the predicate will return true if the
+  ``matchdict`` has a key which exists with any value.
+
+  When the ``match_val`` contains a ``:`` (colon), it will be split at
+  the first colon; the left hand of that split will considered a key
+  and the right hand a regular expression.  For example, in
+  ``action:\w+\.html``, the key part is ``action``, the regex part is
+  ``\w+\.html``.  The resulting predicate will only be true if the
+  matchdict contains a key that matches the key part *and* the
+  matchdict value is matched by the regex part.
+
+  If ``match_val`` is not specified, the composition, presence or
+  absence of values in the matchdict is not taken into consideration
+  when deciding whether or not to invoke the associated view callable.
+
 ``custom_predicates``
   If ``custom_predicates`` is specified, it must be a sequence of
   references to custom predicate callables.  Use custom predicates