mediagoblin/app.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import os
  18 import urllib
  19
  20 import routes
  21 from webob import Request, exc
  22
  23 from mediagoblin import routing, util, middleware
  24 from mediagoblin.mg_globals import setup_globals
  25 from mediagoblin.init.celery import setup_celery_from_config
  26 from mediagoblin.init import (get_jinja_loader, get_staticdirector,
  27     setup_global_and_app_config, setup_workbench, setup_database,
  28     setup_storage, setup_beaker_cache)
  29
  30
  31 class MediaGoblinApp(object):
  32     """
  33     WSGI application of MediaGoblin
  34
  35     ... this is the heart of the program!
  36     """
  37     def __init__(self, config_path, setup_celery=True):
  38         """
  39         Initialize the application based on a configuration file.
  40
  41         Arguments:
  42          - config_path: path to the configuration file we're opening.
  43          - setup_celery: whether or not to setup celery during init.
  44            (Note: setting 'celery_setup_elsewhere' also disables
  45            setting up celery.)
  46         """
  47         ##############
  48         # Setup config
  49         ##############
  50
  51         # Open and setup the config
  52         global_config, app_config = setup_global_and_app_config(config_path)
  53
  54         ##########################################
  55         # Setup other connections / useful objects
  56         ##########################################
  57
  58         # Set up the database
  59         self.connection, self.db = setup_database()
  60
  61         # Get the template environment
  62         self.template_loader = get_jinja_loader(
  63             app_config.get('user_template_path'))
  64
  65         # Set up storage systems
  66         self.public_store, self.queue_store = setup_storage()
  67
  68         # set up routing
  69         self.routing = routing.get_mapper()
  70
  71         # set up staticdirector tool
  72         self.staticdirector = get_staticdirector(app_config)
  73
  74         # set up caching
  75         self.cache = setup_beaker_cache()
  76
  77         # Setup celery, if appropriate
  78         if setup_celery and not app_config.get('celery_setup_elsewhere'):
  79             if os.environ.get('CELERY_ALWAYS_EAGER'):
  80                 setup_celery_from_config(
  81                     app_config, global_config,
  82                     force_celery_always_eager=True)
  83             else:
  84                 setup_celery_from_config(app_config, global_config)
  85
  86         #######################################################
  87         # Insert appropriate things into mediagoblin.mg_globals
  88         #
  89         # certain properties need to be accessed globally eg from
  90         # validators, etc, which might not access to the request
  91         # object.
  92         #######################################################
  93
  94         setup_globals(app = self)
  95
  96         # Workbench *currently* only used by celery, so this only
  97         # matters in always eager mode :)
  98         setup_workbench()
  99
 100         # instantiate application middleware
 101         self.middleware = [util.import_component(m)(self)
 102                            for m in middleware.ENABLED_MIDDLEWARE]
 103
 104
 105     def __call__(self, environ, start_response):
 106         request = Request(environ)
 107
 108         # pass the request through our middleware classes
 109         for m in self.middleware:
 110             response = m.process_request(request)
 111             if response is not None:
 112                 return response(environ, start_response)
 113
 114         ## Routing / controller loading stuff
 115         path_info = request.path_info
 116         route_match = self.routing.match(path_info)
 117
 118         ## Attach utilities to the request object
 119         request.matchdict = route_match
 120         request.urlgen = routes.URLGenerator(self.routing, environ)
 121         # Do we really want to load this via middleware?  Maybe?
 122         request.session = request.environ['beaker.session']
 123         # Attach self as request.app
 124         # Also attach a few utilities from request.app for convenience?
 125         request.app = self
 126         request.locale = util.get_locale_from_request(request)
 127
 128         request.template_env = util.get_jinja_env(
 129             self.template_loader, request.locale)
 130         request.db = self.db
 131         request.staticdirect = self.staticdirector
 132
 133         util.setup_user_in_request(request)
 134
 135         # No matching page?
 136         if route_match is None:
 137             # Try to do see if we have a match with a trailing slash
 138             # added and if so, redirect
 139             if not path_info.endswith('/') \
 140                     and request.method == 'GET' \
 141                     and self.routing.match(path_info + '/'):
 142                 new_path_info = path_info + '/'
 143                 if request.GET:
 144                     new_path_info = '%s?%s' % (
 145                         new_path_info, urllib.urlencode(request.GET))
 146                 redirect = exc.HTTPFound(location=new_path_info)
 147                 return request.get_response(redirect)(environ, start_response)
 148
 149             # Okay, no matches.  404 time!
 150             request.matchdict = {}  # in case our template expects it
 151             return util.render_404(request)(environ, start_response)
 152
 153         controller = util.import_component(route_match['controller'])
 154         request.start_response = start_response
 155
 156         # get the response from the controller
 157         response = controller(request)
 158
 159         # pass the response through the middleware
 160         for m in self.middleware[::-1]:
 161             m.process_response(request, response)
 162
 163         return response(environ, start_response)
 164
 165
 166 def paste_app_factory(global_config, **app_config):
 167     mgoblin_app = MediaGoblinApp(app_config['config'])
 168
 169     return mgoblin_app