Ticket #14389: future_url-1.diff

django/templatetags/future_url.py

@@ +1 @@
+from django.conf import settings
+from django.template import Library, Node, TemplateSyntaxError
+from django.template.defaulttags import kwarg_re
+
+
+register = Library()
+
+
+class URLNode(Node):
+
+    def __init__(self, view_name, args, kwargs, asvar):
+        self.view_name = view_name
+        self.args = args
+        self.kwargs = kwargs
+        self.asvar = asvar
+
+    def render(self, context):
+        from django.core.urlresolvers import reverse, NoReverseMatch
+        args = [arg.resolve(context) for arg in self.args]
+        kwargs = dict([(smart_str(k, 'ascii'), v.resolve(context))
+                       for k, v in self.kwargs.items()])
+
+        view_name = self.view_name.resolve(context)
+
+        # Try to look up the URL twice: once given the view name, and again
+        # relative to what we guess is the "main" app. If they both fail,
+        # re-raise the NoReverseMatch unless we're using the
+        # {% url ... as var %} construct in which cause return nothing.
+        url = ''
+        try:
+            url = reverse(view_name, args=args, kwargs=kwargs,
+                current_app=context.current_app)
+        except NoReverseMatch, e:
+            if settings.SETTINGS_MODULE:
+                project_name = settings.SETTINGS_MODULE.split('.')[0]
+                try:
+                    url = reverse(project_name + '.' + view_name,
+                              args=args, kwargs=kwargs,
+                              current_app=context.current_app)
+                except NoReverseMatch:
+                    if self.asvar is None:
+                        # Re-raise the original exception, not the one with
+                        # the path relative to the project. This makes a
+                        # better error message.
+                        raise e
+            else:
+                if self.asvar is None:
+                    raise e
+
+        if self.asvar:
+            context[self.asvar] = url
+            return ''
+        else:
+            return url
+
+
+def url(parser, token):
+    """
+    Returns an absolute URL matching given view with its parameters.
+
+    This is a way to define links that aren't tied to a particular URL
+    configuration::
+
+        {% url "path.to.some_view" arg1 arg2 %}
+
+        or
+
+        {% url "path.to.some_view" name1=value1 name2=value2 %}
+
+    The first argument is a path to a view. It can be an absolute python path
+    or just ``app_name.view_name`` without the project name if the view is
+    located inside the project.  Other arguments are comma-separated values
+    that will be filled in place of positional and keyword arguments in the
+    URL. All arguments for the URL should be present.
+
+    For example if you have a view ``app_name.client`` taking client's id and
+    the corresponding line in a URLconf looks like this::
+
+        ('^client/(\d+)/$', 'app_name.client')
+
+    and this app's URLconf is included into the project's URLconf under some
+    path::
+
+        ('^clients/', include('project_name.app_name.urls'))
+
+    then in a template you can create a link for a certain client like this::
+
+        {% url "app_name.client" client.id %}
+
+    The URL will look like ``/clients/client/123/``.
+    """
+    bits = token.split_contents()
+    if len(bits) < 2:
+        raise TemplateSyntaxError("'%s' takes at least one argument"
+                                  " (path to a view)" % bits[0])
+    viewname = parser.compile_filter(bits[1])
+    args = []
+    kwargs = {}
+    asvar = None
+    bits = bits[2:]
+    if len(bits) >= 2 and bits[-2] == 'as':
+        asvar = bits[-1]
+        bits = bits[:-2]
+
+    if len(bits):
+        for bit in bits:
+            match = kwarg_re.match(bit)
+            if not match:
+                raise TemplateSyntaxError("Malformed arguments to url tag")
+            name, value = match.groups()
+            if name:
+                kwargs[name] = parser.compile_filter(value)
+            else:
+                args.append(parser.compile_filter(value))
+
+    return URLNode(viewname, args, kwargs, asvar)
+url = register.tag(url)

django/template/defaulttags.py

@@ -1111 +1111 @@
 
     The URL will look like ``/clients/client/123/``.
     """
+
+    import warnings
+    warnings.warn('The old style url tag is being deprecated. '
+                  'You can start using the new style url (link to docs).',
+                  category=PendingDeprecationWarning)
+
     bits = token.split_contents()
     if len(bits) < 2:
         raise TemplateSyntaxError("'%s' takes at least one argument"

tests/regressiontests/templates/tests.py

@@ -1274 +1274 @@
             'url-asvar02': ('{% url regressiontests.templates.views.index as url %}{{ url }}', {}, '/url_tag/'),
             'url-asvar03': ('{% url no_such_view as url %}{{ url }}', {}, ''),
 
+            # Future url tag
+            'url-future01': ('{% load future_url %}{% url "regressiontests.templates.views.client" client.id %}', {'client': {'id': 1}}, '/url_tag/client/1/'),
+            'url-future02': ('{% load future_url %}{% url url_from_var client.id %}', {'client': {'id': 1}, 'url_from_var': 'regressiontests.templates.views.client'}, '/url_tag/client/1/'),
+
+            # Future url failures
+            'url-future-fail01': ('{% load future_url %}{% url regressiontests.templates.views.client client.id %}', {'client': {'id': 1}}, urlresolvers.NoReverseMatch),
+
             ### CACHE TAG ######################################################
             'cache01': ('{% load cache %}{% cache -1 test %}cache01{% endcache %}', {}, 'cache01'),
             'cache02': ('{% load cache %}{% cache -1 test %}cache02{% endcache %}', {}, 'cache02'),

docs/ref/templates/builtins.txt

@@ -1005 +1005 @@
 signs. Did we mention you shouldn't use this syntax in any new
 projects?
 
+.. versionchanged:: 1.3
+
+If you find yourself needing to use a context variable as the path
+to view, you can now do that. To do so you must load a new url tag
+that overwrites the previous tag.
+
+For example::
+
+    {% load future_url %}
+    {% url path_to_view_var arg1 arg2 %}
+
+Now if you have ``path_to_view_var`` defined in your template context
+it will use that value. Please note that old paths or patterns that are
+not context variables need to be quoted using the new url tag.
+
+For example::
+
+    {% url "path.to.view" arg1 arg2 %}
+
+The new url tag also drops support for the old style comma separated
+arguments.
+
+In version 1.3 the old url tag throws a ``PendingDeprecationWarning``,
+then is version 1.4 this will move to a ``DeprecationWarning`` and finally
+in version 1.5 the old tag will be removed and replaced by the new tag.
+
 .. templatetag:: widthratio
 
 widthratio