request: add a static_resource method to Request instances

src/milla/__init__.py

@@ -70,3 +70,42 @@ class Request(Request):
         if vars:
             url += '?' + urllib.urlencode(vars)
         return url
+
+    def static_resource(self, path):
+        '''Return a URL to the given static resource
+
+        This method combines the defined static resource root URL with the
+        given path to construct a complete URL to the given resource. The
+        resource root should be defined in the application configuration
+        dictionary, under the name ``milla.static_root``, for example::
+
+            app = milla.Application(dispatcher)
+            app.config.update({
+                'milla.static_root': '/static/'
+            })
+
+        Then, calling ``static_resource`` on a :py:class:`Request` object
+        (i.e. inside a controller callable) would combine the given path
+        with ``/static/``, like this::
+
+            request.static_resource('/images/foo.png')
+
+        would return ``/static/images/foo.png``.
+
+        If no ``milla.static_root`` key is found in the configuration
+        dictionary, the path will be returned unaltered.
+
+        :param path: Path to the resource, relative to the defined root
+        '''
+
+        try:
+            root = self.config['milla.static_root']
+        except KeyError:
+            return path
+
+        if path.startswith('/'):
+            path = path[1:]
+        if not root.endswith('/'):
+            root += '/'
+
+        return urlparse.urljoin(root, path)