From 5fc0d36724a6197c8c0106e846d8e78e1219b1fe Mon Sep 17 00:00:00 2001
From: Chris McDonough <chrism@plope.com>
Date: Wed, 31 Jul 2013 02:30:07 +0200
Subject: [PATCH] first cut at indicating that only some predicates are negatable
---
pyramid/config/util.py | 8 +++
docs/narr/viewconfig.rst | 18 +++++++--
pyramid/config/predicates.py | 8 ++++
pyramid/config/__init__.py | 12 +++++
pyramid/tests/test_config/test_util.py | 26 +++++++++---
5 files changed, 59 insertions(+), 13 deletions(-)
diff --git a/docs/narr/viewconfig.rst b/docs/narr/viewconfig.rst
index fd32293..9292548 100644
--- a/docs/narr/viewconfig.rst
+++ b/docs/narr/viewconfig.rst
@@ -560,8 +560,8 @@
Inverting Predicate Values
~~~~~~~~~~~~~~~~~~~~~~~~~~
-You can invert the meaning of any predicate value by wrapping it in a call to
-:class:`pyramid.config.not_`.
+You can invert the meaning of a supported predicate value by wrapping it in a
+call to :class:`pyramid.config.not_`.
.. code-block:: python
:linenos:
@@ -571,11 +571,21 @@
config.add_view(
'mypackage.views.my_view',
route_name='ok',
- request_method=not_('POST')
+ header=not_('X-Foo')
)
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.
+does not have the ``X-Foo`` header, at least if no other view is more specific.
+
+A predicate must be *negatable* to use ``not_`` against its value. The current
+set of built-in negatable predicates are: ``path_info``, ``request_param``,
+``header``, ``containment``, ``request_type``, ``match_param``,
+``physical_path``, and ``effective_principals``. If you try to use ``not_``
+against a non-negatable predicate, an error will be raised at startup time.
+
+You can make sure a custom view predicate added via
+:meth:`pyramid.config.Configurator.add_view_predicate` is negatable by adding a
+``negatable`` attribute to it that is True.
This technique of wrapping a predicate value in ``not_`` can be used anywhere
predicate values are accepted:
diff --git a/pyramid/config/__init__.py b/pyramid/config/__init__.py
index d52ee0e..698c943 100644
--- a/pyramid/config/__init__.py
+++ b/pyramid/config/__init__.py
@@ -1152,7 +1152,17 @@
# and "i" exist for sorting purposes after conflict resolution.
ainfo = (order, i, action)
- discriminator = undefer(action['discriminator'])
+ try:
+ discriminator = undefer(action['discriminator'])
+ except:
+ t, v, tb = sys.exc_info()
+ try:
+ reraise(ConfigurationExecutionError,
+ ConfigurationExecutionError(t, v, action['info']),
+ tb)
+ finally:
+ del t, v, tb
+
action['discriminator'] = discriminator
if discriminator is None:
diff --git a/pyramid/config/predicates.py b/pyramid/config/predicates.py
index c8f66e8..6caa875 100644
--- a/pyramid/config/predicates.py
+++ b/pyramid/config/predicates.py
@@ -48,6 +48,7 @@
return request.method in self.val
class PathInfoPredicate(object):
+ negatable = True
def __init__(self, val, config):
self.orig = val
try:
@@ -65,6 +66,7 @@
return self.val.match(request.upath_info) is not None
class RequestParamPredicate(object):
+ negatable = True
def __init__(self, val, config):
val = as_sorted_tuple(val)
reqs = []
@@ -95,6 +97,7 @@
return True
class HeaderPredicate(object):
+ negatable = True
def __init__(self, val, config):
name = val
v = None
@@ -137,6 +140,7 @@
return self.val in request.accept
class ContainmentPredicate(object):
+ negatable = True
def __init__(self, val, config):
self.val = config.maybe_dotted(val)
@@ -150,6 +154,7 @@
return find_interface(ctx, self.val) is not None
class RequestTypePredicate(object):
+ negatable = True
def __init__(self, val, config):
self.val = val
@@ -162,6 +167,7 @@
return self.val.providedBy(request)
class MatchParamPredicate(object):
+ negatable = True
def __init__(self, val, config):
val = as_sorted_tuple(val)
self.val = val
@@ -258,6 +264,7 @@
return True
class PhysicalPathPredicate(object):
+ negatable = True
def __init__(self, val, config):
if is_nonstr_iter(val):
self.val = tuple(val)
@@ -276,6 +283,7 @@
return False
class EffectivePrincipalsPredicate(object):
+ negatable = True
def __init__(self, val, config):
if is_nonstr_iter(val):
self.val = set(val)
diff --git a/pyramid/config/util.py b/pyramid/config/util.py
index a98e71c..a0cbeca 100644
--- a/pyramid/config/util.py
+++ b/pyramid/config/util.py
@@ -110,7 +110,13 @@
notted = True
pred = predicate_factory(realval, config)
if notted:
- pred = Notted(pred)
+ if getattr(pred, 'negatable', False):
+ pred = Notted(pred)
+ else:
+ raise ConfigurationError(
+ '%s is not a negatable predicate' % (pred.text(),),
+ )
+
hashes = pred.phash()
if not is_nonstr_iter(hashes):
hashes = [hashes]
diff --git a/pyramid/tests/test_config/test_util.py b/pyramid/tests/test_config/test_util.py
index f6cd414..c813cc5 100644
--- a/pyramid/tests/test_config/test_util.py
+++ b/pyramid/tests/test_config/test_util.py
@@ -365,19 +365,31 @@
from pyramid.exceptions import ConfigurationError
self.assertRaises(ConfigurationError, self._callFUT, unknown=1)
- def test_notted(self):
+ def test_notted_configerror(self):
+ from pyramid.exceptions import ConfigurationError
from pyramid.config import not_
- from pyramid.testing import DummyRequest
- request = DummyRequest()
- _, predicates, _ = self._callFUT(
+ self.assertRaises(ConfigurationError, self._callFUT,
xhr='xhr',
request_method=not_('POST'),
header=not_('header'),
)
+
+ def test_notted_ok(self):
+ from pyramid.config import not_
+ _, predicates, _ = self._callFUT(
+ xhr='xhr',
+ path_info=not_('/path_info'),
+ header=not_('header'),
+ )
+ from pyramid.testing import DummyRequest
+ request = DummyRequest()
+ request.upath_info = request.path_info
+ request.is_xhr = False
self.assertEqual(predicates[0].text(), 'xhr = True')
- self.assertEqual(predicates[1].text(),
- "!request_method = POST")
- self.assertEqual(predicates[2].text(), '!header header')
+ self.assertEqual(predicates[1].text(), '!path_info = /path_info')
+ self.assertEqual(predicates[2].text(),
+ "!header header")
+ self.assertEqual(predicates[0](None, request), False)
self.assertEqual(predicates[1](None, request), True)
self.assertEqual(predicates[2](None, request), True)
--
Gitblit v1.9.3