search/product_search_python/base_handler.py

   1 #!/usr/bin/env python
   2 #
   3 # Copyright 2012 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 """ The base request handler class.
  18 """
  19
  20
  21 import webapp2
  22 from webapp2_extras import jinja2
  23 import json
  24
  25 from google.appengine.api import users
  26
  27
  28 class BaseHandler(webapp2.RequestHandler):
  29   """The other handlers inherit from this class.  Provides some helper methods
  30   for rendering a template and generating template links."""
  31
  32   @classmethod
  33   def logged_in(cls, handler_method):
  34     """
  35     This decorator requires a logged-in user, and returns 403 otherwise.
  36     """
  37     def auth_required(self, *args, **kwargs):
  38       if (users.get_current_user() or
  39           self.request.headers.get('X-AppEngine-Cron')):
  40         handler_method(self, *args, **kwargs)
  41       else:
  42         self.error(403)
  43     return auth_required
  44
  45   @webapp2.cached_property
  46   def jinja2(self):
  47     return jinja2.get_jinja2(app=self.app)
  48
  49   def render_template(self, filename, template_args):
  50     template_args.update(self.generateSidebarLinksDict())
  51     self.response.write(self.jinja2.render_template(filename, **template_args))
  52
  53   def render_json(self, response):
  54     self.response.write("%s(%s);" % (self.request.GET['callback'],
  55                                      json.dumps(response)))
  56
  57   def getLoginLink(self):
  58     """Generate login or logout link and text, depending upon the logged-in
  59     status of the client."""
  60     if users.get_current_user():
  61       url = users.create_logout_url(self.request.uri)
  62       url_linktext = 'Logout'
  63     else:
  64       url = users.create_login_url(self.request.uri)
  65       url_linktext = 'Login'
  66     return (url, url_linktext)
  67
  68   def getAdminManageLink(self):
  69     """Build link to the admin management page, if the user is logged in."""
  70     if users.get_current_user():
  71       admin_url = '/admin/manage'
  72       return (admin_url, 'Admin/Add sample data')
  73     else:
  74       return (None, None)
  75
  76   def createProductAdminLink(self):
  77     if users.get_current_user():
  78       admin_create_url = '/admin/create_product'
  79       return (admin_create_url, 'Create new product (admin)')
  80     else:
  81       return (None, None)
  82
  83   def generateSidebarLinksDict(self):
  84     """Build a dict containing login/logout and admin links, which will be
  85     included in the sidebar for all app pages."""
  86
  87     url, url_linktext = self.getLoginLink()
  88     admin_create_url, admin_create_text = self.createProductAdminLink()
  89     admin_url, admin_text = self.getAdminManageLink()
  90     return {
  91         'admin_create_url': admin_create_url,
  92         'admin_create_text': admin_create_text,
  93         'admin_url': admin_url,
  94         'admin_text': admin_text,
  95         'url': url,
  96         'url_linktext': url_linktext
  97         }
  98