使用Google App Engine的webapp2裝飾器路由

Question

我想通過裝飾我的RequestHandler對象來定義路由，而不是在創建應用程序時為其提供列表。

我的WSGIApplication定義如下：

class WSGIApplication(webapp2.WSGIApplication):
    def __init__(self, *args, **kwargs):
        super(WSGIApplication, self).__init__(*args, **kwargs)
        self.router.set_dispatcher(self.__class__.custom_dispatcher)

    @staticmethod
    def custom_dispatcher(router, request, response):
        rv = router.default_dispatcher(request, response)
        if isinstance(rv, basestring):
            rv = webapp2.Response(rv)
        elif isinstance(rv, tuple):
            rv = webapp2.Response(*rv)

        return rv

    def route(self, url, name):
        def outer_wrapped(cls):
            logging.info("Adding route %s to class %s with name %s"
                         % (url, cls, name))
            self.router.add(RedirectRoute(url, cls,
                                          name=name,
                                          strict_slash=True))
            return cls
        return outer_wrapped

在package.utils

我在package.application定義了我的應用程序

app.yaml有

application: theapplication
version: 1
runtime: python27
api_version: 1
threadsafe: yes

handlers:
- url: .*
  script: package.main.application
  secure: always

package.main如下：

from package.application import application
from package.pages import pages

package.application如下（其中的秘密密鑰已散列）：

from package import utils

conf = {}
conf['webapp2_extras.sessions'] = {'secret_key':
    """##############################################"""}

application = utils.WSGIApplication([], config=conf)

這是package.pages的幾個處理程序：

from package.application import application as app


@app.route('/conversations', 'view_messages')
class Messages(BaseHandler):
    @users.require_login
    def get(self):
        conversations = self.current_user.get_user_conversations()
        return self.render('conversations.slim', conversations=conversations)


@app.route('/', 'index')
class Index(BaseHandler):
    def get(self):
        return self.render('index.slim')

索引頁工作正常，其他所有404都正常運行，日志僅顯示：

INFO     2012-07-23 14:23:46,258 __init__.py:26] /notifications
INFO     2012-07-23 14:23:46,272 dev_appserver.py:2952] "GET /notifications HTTP/1.1" 404 -

我認為這是由於appengine的導入緩存導致某種形式的裝飾器無法運行並將其自身添加到應用程序而造成的。

當然，我以為自己對導致問題的原因有任何線索的陷阱深陷其中。 在嘗試每次分派之前，我添加了更多的日志記錄語句以輸出路由列表，並且發現所有路由都在路由器中，這與預期的一樣：

    ...
    def custom_dispatcher(router, request, response):
        logging.info(router.match_routes)
        logging.info(router.build_routes)
        rv = router.default_dispatcher(request, response)
    ...

將我的瀏覽器指向/ conversations時，輸出以下日志：

INFO     2012-08-04 13:16:40,513 utils.py:13] [<Route('/friendship', <class 'package.pages.pages.Friendship'>, name='friendship', defaults={}, build_only=False)>, <Route('/friendship/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/friendship', <class 'package.pages.pages.Friendship'>, name='friendship', defaults={}, build_only=False)>>, '_name': 'friendship'}, build_only=False)>, <Route('/signup', <class 'package.pages.pages.Signup'>, name='signup', defaults={}, build_only=False)>, <Route('/signup/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/signup', <class 'package.pages.pages.Signup'>, name='signup', defaults={}, build_only=False)>>, '_name': 'signup'}, build_only=False)>, <Route('/preferences', <class 'package.pages.pages.UserPage'>, name='user_prefs', defaults={}, build_only=False)>, <Route('/preferences/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/preferences', <class 'package.pages.pages.UserPage'>, name='user_prefs', defaults={}, build_only=False)>>, '_name': 'user_prefs'}, build_only=False)>, <Route('/<username:[a-zA-Z]+>', <class 'package.pages.pages.UserPage'>, name='user_page', defaults={}, build_only=False)>, <Route('/<username:[a-zA-Z]+>/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/<username:[a-zA-Z]+>', <class 'package.pages.pages.UserPage'>, name='user_page', defaults={}, build_only=False)>>, '_name': 'user_page'}, build_only=False)>, <Route('/message', <class 'package.pages.pages.SendMessagePage'>, name='send_message', defaults={}, build_only=False)>, <Route('/message/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/message', <class 'package.pages.pages.SendMessagePage'>, name='send_message', defaults={}, build_only=False)>>, '_name': 'send_message'}, build_only=False)>, <Route('/conversations', <class 'package.pages.pages.Messages'>, name='view_messages', defaults={}, build_only=False)>, <Route('/conversations/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/conversations', <class 'package.pages.pages.Messages'>, name='view_messages', defaults={}, build_only=False)>>, '_name': 'view_messages'}, build_only=False)>, <Route('/conversation/<conversation_id>', <class 'package.pages.pages.ConversationPage'>, name='conversation', defaults={}, build_only=False)>, <Route('/conversation/<conversation_id>/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/conversation/<conversation_id>', <class 'package.pages.pages.ConversationPage'>, name='conversation', defaults={}, build_only=False)>>, '_name': 'conversation'}, build_only=False)>, <Route('/boards', <class 'package.pages.pages.Boards'>, name='view_boards', defaults={}, build_only=False)>, <Route('/boards/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/boards', <class 'package.pages.pages.Boards'>, name='view_boards', defaults={}, build_only=False)>>, '_name': 'view_boards'}, build_only=False)>, <Route('/boards/<board>', <class 'package.pages.pages.BoardPage'>, name='view_board', defaults={}, build_only=False)>, <Route('/boards/<board>/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/boards/<board>', <class 'package.pages.pages.BoardPage'>, name='view_board', defaults={}, build_only=False)>>, '_name': 'view_board'}, build_only=False)>, <Route('/boards/<board>/new_thread', <class 'package.pages.pages.NewThreadPage'>, name='new_thread', defaults={}, build_only=False)>, <Route('/boards/<board>/new_thread/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/boards/<board>/new_thread', <class 'package.pages.pages.NewThreadPage'>, name='new_thread', defaults={}, build_only=False)>>, '_name': 'new_thread'}, build_only=False)>, <Route('/notifications', <class 'package.pages.pages.Notifications'>, name='notifications', defaults={}, build_only=False)>, <Route('/notifications/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/notifications', <class 'package.pages.pages.Notifications'>, name='notifications', defaults={}, build_only=False)>>, '_name': 'notifications'}, build_only=False)>, <Route('/img/<blob_key>', <class 'package.pages.pages.DisplayImagePage'>, name='display_image', defaults={}, build_only=False)>, <Route('/img/<blob_key>/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/img/<blob_key>', <class 'package.pages.pages.DisplayImagePage'>, name='display_image', defaults={}, build_only=False)>>, '_name': 'display_image'}, build_only=False)>, <Route('/', <class 'package.pages.pages.Index'>, name='index', defaults={}, build_only=False)>, <Route('/', <class 'webapp2.RedirectHandler'>, name=None, defaults={'_uri': <bound method RedirectRoute._redirect of <Route('/', <class 'package.pages.pages.Index'>, name='index', defaults={}, build_only=False)>>, '_name': 'index'}, build_only=False)>]
INFO     2012-08-04 13:16:40,513 utils.py:14] {'index': <Route('/', <class 'package.pages.pages.Index'>, name='index', defaults={}, build_only=False)>, 'view_boards': <Route('/boards', <class 'package.pages.pages.Boards'>, name='view_boards', defaults={}, build_only=False)>, 'notifications': <Route('/notifications', <class 'package.pages.pages.Notifications'>, name='notifications', defaults={}, build_only=False)>, 'friendship': <Route('/friendship', <class 'package.pages.pages.Friendship'>, name='friendship', defaults={}, build_only=False)>, 'signup': <Route('/signup', <class 'package.pages.pages.Signup'>, name='signup', defaults={}, build_only=False)>, 'view_messages': <Route('/conversations', <class 'package.pages.pages.Messages'>, name='view_messages', defaults={}, build_only=False)>, 'conversation': <Route('/conversation/<conversation_id>', <class 'package.pages.pages.ConversationPage'>, name='conversation', defaults={}, build_only=False)>, 'send_message': <Route('/message', <class 'package.pages.pages.SendMessagePage'>, name='send_message', defaults={}, build_only=False)>, 'new_thread': <Route('/boards/<board>/new_thread', <class 'package.pages.pages.NewThreadPage'>, name='new_thread', defaults={}, build_only=False)>, 'view_board': <Route('/boards/<board>', <class 'package.pages.pages.BoardPage'>, name='view_board', defaults={}, build_only=False)>, 'display_image': <Route('/img/<blob_key>', <class 'package.pages.pages.DisplayImagePage'>, name='display_image', defaults={}, build_only=False)>, 'user_prefs': <Route('/preferences', <class 'package.pages.pages.UserPage'>, name='user_prefs', defaults={}, build_only=False)>, 'user_page': <Route('/<username:[a-zA-Z]+>', <class 'package.pages.pages.UserPage'>, name='user_page', defaults={}, build_only=False)>}
INFO     2012-08-04 13:16:40,515 __init__.py:26] /conversations
INFO     2012-08-04 13:16:40,533 dev_appserver.py:2952] "GET /conversations HTTP/1.1" 404 -
INFO     2012-08-04 13:16:40,626 dev_appserver.py:2952] "GET /favicon.ico HTTP/1.1" 200 -

我到底沒有注意到什么？

Answer 1

我有一條路由會覆蓋所有其他路由，但會在它們上面引發404（/ username會導致用戶頁面；沒有用戶稱為“對話”）。 我忘了使此路由在切換到裝飾器路由方法時具有最低優先級。

我首先使用相同的路由方法構建了一個最小的應用程序，以查看它在應用程序引擎上的運行情況，從而弄清楚了這一點。 然后，我在處理程序中捕獲了HTTPNotFound異常，並在發生異常時打印了堆棧跟蹤。 這很清楚，這是我的用戶頁面類的get方法中的一行故意拋出了404，然后問題就很明顯了。