@@ -393,6 +393,7 @@ class RequestHandler(object): _=self.locale.translate, static_url=self.static_url, xsrf_form_html=self.xsrf_form_html, + reverse_url=self.application.reverse_url ) args.update(self.ui) args.update(kwargs) @@ -659,6 +660,7 @@ class RequestHandler(object): else: return base + url_path + path + def async_callback(self, callback, *args, **kwargs): """Wrap callbacks with this if they are used on asynchronous requests. @@ -873,6 +875,7 @@ class Application(object): else: self.transforms = transforms self.handlers = [] + self.named_handlers = {} self.default_host = default_host self.settings = settings self.ui_modules = {} @@ -923,6 +926,9 @@ class Application(object): pattern += "$" handlers.append((re.compile(pattern), handler, kwargs)) + if isinstance(handler_tuple, URLSpec): + self.named_handlers[handler_tuple.name] = handler_tuple + def add_transform(self, transform_class): """Adds the given OutputTransform to our transform list.""" self.transforms.append(transform_class) @@ -994,6 +1000,14 @@ class Application(object): handler._execute(transforms, *args) return handler + def reverse_url(self, name, *args): + """Returns a URL path for handler named `name` + + The handler must be added to the application as a URLSpec + """ + if name in self.named_handlers: + return self.named_handlers[name].reverse(*args) + raise KeyError("%s not found in named urls" % name) class HTTPError(Exception): """An exception that will turn into an HTTP error response.""" @@ -1222,6 +1236,73 @@ class UIModule(object): def render_string(self, path, **kwargs): return self.handler.render_string(path, **kwargs) +class URLSpec(object): + """A tuple like object for specifying handlers in an application + + Rather than hard code URLs in templates, or redirects, HandlerSpecs allow + us to give a handler a name which we can then use to lookup and compute the + URL. + """ + __slots__ = ('pattern', 'handler', 'kwargs', 'name', + 'path', 'group_count') + def __init__(self, pattern, handler, kwargs=None, name=None): + if not pattern.endswith('$'): + pattern += '$' + self.pattern = pattern + self.handler = handler + self.kwargs = kwargs + self.name = name + path, gc = self._find_groups(pattern) + self.path = path + self.group_count = gc + + def __len__(self): + return 3 if self.kwargs else 2 + + def __getitem__(self, i): + if not isinstance(i, int): + raise TypeError('indices must be integegers') + length = len(self) + attr = self.__slots__[:length][i] + + return getattr(self, attr) + + def _find_groups(self, pattern): + """Returns a tuple (reverse string, group count) for a url. + + For example: Given the url pattern /([0-9]{4})/([a-z-]+)/, this method + would return ('/%s/%s/', 2). + """ + if pattern.startswith('^'): + pattern = pattern[1:] + if pattern.endswith('$'): + pattern = pattern[:-1] + + _pattern = re.compile(pattern) + assert _pattern.groups == pattern.count('('), "Pattern's group count"\ + " does not match the number of right parenthesis" + + pieces = [] + for fragment in pattern.split('('): + if ')' in fragment: + paren_loc = fragment.index(')') + if paren_loc >= 0: + pieces.append('%s' + fragment[paren_loc + 1:]) + else: + pieces.append(fragment) + + return (''.join(pieces), _pattern.groups) + + def reverse(self, *args): + assert len(args) == self.group_count, "required number of arguments "\ + "not found" + import pdb + pdb.set_trace() + if not len(args): + return self.path + return self.path % tuple([str(a) for a in args]) + +url = URLSpec def _utf8(s): if isinstance(s, unicode): tornado/web.py 63f92807a431ab513afc8862718eee39e0bedb7a apgwoz git@apgwoz.com http://github.com/apgwoz/tornado/commit/0b57fbcf992647b6674ad9e433bffffac900f83a 0b57fbcf992647b6674ad9e433bffffac900f83a 2009-10-18T15:18:14-07:00 2009-10-18T15:18:14-07:00 * first crack at reverse_url, which allows you to name pattern, handler, kwarg handler specs to reverse a url in a template, or within an app. c8f0c549e3293096653654c241b819f9a90fb8cd apgwoz git@apgwoz.com