thirdparty/google_appengine/google/appengine/ext/webapp/util.py
changeset 109 620f9b141567
child 686 df109be0567c
equal deleted inserted replaced
108:261778de26ff 109:620f9b141567
       
     1 #!/usr/bin/env python
       
     2 #
       
     3 # Copyright 2007 Google Inc.
       
     4 #
       
     5 # Licensed under the Apache License, Version 2.0 (the "License");
       
     6 # you may not use this file except in compliance with the License.
       
     7 # You may obtain a copy of the License at
       
     8 #
       
     9 #     http://www.apache.org/licenses/LICENSE-2.0
       
    10 #
       
    11 # Unless required by applicable law or agreed to in writing, software
       
    12 # distributed under the License is distributed on an "AS IS" BASIS,
       
    13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       
    14 # See the License for the specific language governing permissions and
       
    15 # limitations under the License.
       
    16 #
       
    17 
       
    18 """Convience functions for the Webapp framework."""
       
    19 
       
    20 
       
    21 
       
    22 
       
    23 
       
    24 __all__ = ["login_required", "run_wsgi_app"]
       
    25 
       
    26 import os
       
    27 import sys
       
    28 import wsgiref.util
       
    29 
       
    30 from google.appengine.api import users
       
    31 from google.appengine.ext import webapp
       
    32 
       
    33 
       
    34 def login_required(handler_method):
       
    35   """A decorator to require that a user be logged in to access a handler.
       
    36 
       
    37   To use it, decorate your get() or post() method like this:
       
    38 
       
    39     @login_required
       
    40     def get(self):
       
    41       user = users.GetCurrentUser(self)
       
    42       self.response.out.write('Hello, ' + user.nickname())
       
    43 
       
    44   We will redirect to a login page if the user is not logged in. We always
       
    45   redirect to the request URI, and Google Accounts only redirects back as a GET request,
       
    46   so this should not be used for POSTs.
       
    47   """
       
    48   def check_login(self, *args):
       
    49     if self.request.method != 'GET':
       
    50       raise webapp.Error('The check_login decorator can only be used for GET '
       
    51                          'requests')
       
    52     user = users.GetCurrentUser()
       
    53     if not user:
       
    54       self.redirect(users.CreateLoginURL(self.request.uri))
       
    55       return
       
    56     else:
       
    57       handler_method(self, *args)
       
    58   return check_login
       
    59 
       
    60 
       
    61 def run_wsgi_app(application):
       
    62   """Runs your WSGI-compliant application object in a CGI environment.
       
    63 
       
    64   Compared to wsgiref.handlers.CGIHandler().run(application), this
       
    65   function takes some shortcuts.  Those are possible because the
       
    66   app server makes stronger promises than the CGI standard.
       
    67   """
       
    68   env = dict(os.environ)
       
    69   env["wsgi.input"] = sys.stdin
       
    70   env["wsgi.errors"] = sys.stderr
       
    71   env["wsgi.version"] = (1, 0)
       
    72   env["wsgi.run_once"] = True
       
    73   env["wsgi.url_scheme"] = wsgiref.util.guess_scheme(env)
       
    74   env["wsgi.multithread"] = False
       
    75   env["wsgi.multiprocess"] = False
       
    76   result = application(env, _start_response)
       
    77   if result is not None:
       
    78     for data in result:
       
    79       sys.stdout.write(data)
       
    80 
       
    81 
       
    82 def _start_response(status, headers, exc_info=None):
       
    83   """A start_response() callable as specified by PEP 333"""
       
    84   if exc_info is not None:
       
    85     raise exc_info[0], exc_info[1], exc_info[2]
       
    86   print "Status: %s" % status
       
    87   for name, val in headers:
       
    88     print "%s: %s" % (name, val)
       
    89   print
       
    90   return sys.stdout.write