Added the ability to name URL patterns. Helps with disambiguity reverse matches.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4901 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/conf/urls/defaults.py

@@ -1,19 +1,25 @@
 from django.core.urlresolvers import RegexURLPattern, RegexURLResolver
 
-__all__ = ['handler404', 'handler500', 'include', 'patterns']
+__all__ = ['handler404', 'handler500', 'include', 'patterns', 'url']
 
 handler404 = 'django.views.defaults.page_not_found'
 handler500 = 'django.views.defaults.server_error'
 
 include = lambda urlconf_module: [urlconf_module]
 
-def patterns(prefix, *tuples):
+def patterns(prefix, *args):
     pattern_list = []
-    for t in tuples:
-        regex, view_or_include = t[:2]
-        default_kwargs = t[2:]
-        if type(view_or_include) == list:
-            pattern_list.append(RegexURLResolver(regex, view_or_include[0], *default_kwargs))
+    for t in args:
+        if isinstance(t, (list, tuple)):
+            pattern_list.append(url(prefix=prefix, *t))
         else:
-            pattern_list.append(RegexURLPattern(regex, prefix and (prefix + '.' + view_or_include) or view_or_include, *default_kwargs))
+            pattern_list.append(t)
     return pattern_list
+
+def url(regex, view, kwargs=None, name=None, prefix=''):
+    if type(view) == list:
+        # For include(...) processing.
+        return RegexURLResolver(regex, view[0], kwargs)
+    else:
+        return RegexURLPattern(regex, prefix and (prefix + '.' + view) or view, kwargs, name)
+

django/core/urlresolvers.py

@@ -88,7 +88,7 @@ class MatchChecker(object):
         return str(value) # TODO: Unicode?
 
 class RegexURLPattern(object):
-    def __init__(self, regex, callback, default_args=None):
+    def __init__(self, regex, callback, default_args=None, name=None):
         # regex is a string representing a regular expression.
         # callback is either a string like 'foo.views.news.stories.story_detail'
         # which represents the path to a module and a view function name, or a
@@ -100,6 +100,7 @@ class RegexURLPattern(object):
             self._callback = None
             self._callback_str = callback
         self.default_args = default_args or {}
+        self.name = name
 
     def resolve(self, path):
         match = self.regex.search(path)
@@ -205,6 +206,7 @@ class RegexURLResolver(object):
             try:
                 lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
             except (ImportError, AttributeError):
+                if func_name != '':
                     raise NoReverseMatch
         for pattern in self.urlconf_module.urlpatterns:
             if isinstance(pattern, RegexURLResolver):
@@ -212,7 +214,7 @@ class RegexURLResolver(object):
                     return pattern.reverse_helper(lookup_view, *args, **kwargs)
                 except NoReverseMatch:
                     continue
-            elif pattern.callback == lookup_view:
+            elif pattern.callback == lookup_view or pattern.name == lookup_view:
                 try:
                     return pattern.reverse_helper(*args, **kwargs)
                 except NoReverseMatch:

docs/url_dispatch.txt

@@ -185,10 +185,25 @@ The first argument to ``patterns()`` is a string ``prefix``. See
 
 The remaining arguments should be tuples in this format::
 
-    (regular expression, Python callback function [, optional dictionary])
+    (regular expression, Python callback function [, optional dictionary [, optional name]])
 
-...where ``optional dictionary`` is optional. (See
-_`Passing extra options to view functions` below.)
+...where ``optional dictionary`` and ``optional name`` are optional. (See
+`Passing extra options to view functions`_ below.)
+
+url
+---
+**New in development version**
+
+The ``url()`` function can be used instead of a tuple as an argument to
+``patterns()``. This is convenient if you wish to specify a name without the
+optional extra arguments dictionary. For example::
+
+    urlpatterns = patterns('',
+        url(r'/index/$', index_view, name="main-view"),
+        ...
+    )
+
+See `Naming URL patterns`_ for why then ``name`` parameter is useful.
 
 handler404
 ----------
@@ -479,3 +494,44 @@ The style you use is up to you.
 
 Note that if you use this technique -- passing objects rather than strings --
 the view prefix (as explained in "The view prefix" above) will have no effect.
+
+Naming URL patterns
+===================
+
+**New in development version**
+
+It is fairly common to use the same view function in multiple URL patterns in
+your URLConf. This leads to problems when you come to do reverse URL matching,
+because the ``permalink()`` decorator and ``{% url %}`` template tag use the
+name of the view function to find a match.
+
+To solve this problem, you can give a name to each of your URL patterns in
+order to distinguish them from other patterns using the same views and
+parameters. You can then use this name wherever you would otherwise use the
+name of the view function. For example, if you URLConf contains::
+
+    urlpatterns = patterns('',
+        url(r'/archive/(\d{4})/$', archive, name="full-archive"),
+        url(r'/archive-summary/(\d{4})/$', archive, {'summary': True}, "arch-summary"),
+    )
+
+...you could refer to either the summary archive view in a template as::
+
+    {% url arch-summary 1945 %}
+
+Even though both URL patterns refer to the ``archive`` view here, using the
+``name`` parameter to ``url()`` allows you to tell them apart in templates.
+
+The string used for the URL name can contain any characters you like. You are
+not restricted to valid Python names.
+
+.. note::
+
+    Make sure that when you name your URLs, you use names that are unlikely to
+    clash with any other application's choice of names. If you call your URL
+    pattern *comment* and another application does the same thing, there is no
+    guarantee which URL will be inserted into your template when you use this
+    name. Putting a prefix on your URL names, perhaps derived from
+    the application name, will decrease the chances of collision. Something
+    like *myapp-comment* is recommended over simply *comment*.
+

tests/regressiontests/templates/tests.py

@@ -692,11 +692,12 @@ class Templates(unittest.TestCase):
             'url01' : ('{% url regressiontests.templates.views.client client.id %}', {'client': {'id': 1}}, '/url_tag/client/1/'),
             'url02' : ('{% url regressiontests.templates.views.client_action client.id,action="update" %}', {'client': {'id': 1}}, '/url_tag/client/1/update/'),
             'url03' : ('{% url regressiontests.templates.views.index %}', {}, '/url_tag/'),
+            'url04' : ('{% url named-client client.id %}', {'client': {'id': 1}}, '/url_tag/named-client/1/'),
 
             # Failures
-            'url04' : ('{% url %}', {}, template.TemplateSyntaxError),
-            'url05' : ('{% url no_such_view %}', {}, ''),
-            'url06' : ('{% url regressiontests.templates.views.client no_such_param="value" %}', {}, ''),
+            'url-fail01' : ('{% url %}', {}, template.TemplateSyntaxError),
+            'url-fail02' : ('{% url no_such_view %}', {}, ''),
+            'url-fail03' : ('{% url regressiontests.templates.views.client no_such_param="value" %}', {}, ''),
         }
 
         # Register our custom template loader.

tests/regressiontests/templates/urls.py

@@ -7,4 +7,5 @@ urlpatterns = patterns('',
     (r'^$', views.index),
     (r'^client/(\d+)/$', views.client),
     (r'^client/(\d+)/(?P<action>[^/]+)/$', views.client_action),
+    url(r'^named-client/(\d+)/$', views.client, name="named-client"),
 )