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)
  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         # Setup celery, if appropriate
  75         if setup_celery and not app_config.get('celery_setup_elsewhere'):
  76             if os.environ.get('CELERY_ALWAYS_EAGER'):
  77                 setup_celery_from_config(
  78                     app_config, global_config,
  79                     force_celery_always_eager=True)
  80             else:
  81                 setup_celery_from_config(app_config, global_config)
  82
  83         #######################################################
  84         # Insert appropriate things into mediagoblin.mg_globals
  85         #
  86         # certain properties need to be accessed globally eg from
  87         # validators, etc, which might not access to the request
  88         # object.
  89         #######################################################
  90
  91         setup_globals(app = self)
  92
  93         # Workbench *currently* only used by celery, so this only
  94         # matters in always eager mode :)
  95         setup_workbench()
  96
  97         # instantiate application middleware
  98         self.middleware = [util.import_component(m)(self)
  99                            for m in middleware.ENABLED_MIDDLEWARE]
 100
 101
 102     def __call__(self, environ, start_response):
 103         request = Request(environ)
 104
 105         # pass the request through our middleware classes
 106         for m in self.middleware:
 107             response = m.process_request(request)
 108             if response is not None:
 109                 return response(environ, start_response)
 110
 111         ## Routing / controller loading stuff
 112         path_info = request.path_info
 113         route_match = self.routing.match(path_info)
 114
 115         ## Attach utilities to the request object
 116         request.matchdict = route_match
 117         request.urlgen = routes.URLGenerator(self.routing, environ)
 118         # Do we really want to load this via middleware?  Maybe?
 119         request.session = request.environ['beaker.session']
 120         # Attach self as request.app
 121         # Also attach a few utilities from request.app for convenience?
 122         request.app = self
 123         request.locale = util.get_locale_from_request(request)
 124
 125         request.template_env = util.get_jinja_env(
 126             self.template_loader, request.locale)
 127         request.db = self.db
 128         request.staticdirect = self.staticdirector
 129
 130         util.setup_user_in_request(request)
 131
 132         # No matching page?
 133         if route_match is None:
 134             # Try to do see if we have a match with a trailing slash
 135             # added and if so, redirect
 136             if not path_info.endswith('/') \
 137                     and request.method == 'GET' \
 138                     and self.routing.match(path_info + '/'):
 139                 new_path_info = path_info + '/'
 140                 if request.GET:
 141                     new_path_info = '%s?%s' % (
 142                         new_path_info, urllib.urlencode(request.GET))
 143                 redirect = exc.HTTPFound(location=new_path_info)
 144                 return request.get_response(redirect)(environ, start_response)
 145
 146             # Okay, no matches.  404 time!
 147             request.matchdict = {}  # in case our template expects it
 148             return util.render_404(request)(environ, start_response)
 149
 150         controller = util.import_component(route_match['controller'])
 151         request.start_response = start_response
 152
 153         # get the response from the controller
 154         response = controller(request)
 155
 156         # pass the response through the middleware
 157         for m in self.middleware[::-1]:
 158             m.process_response(request, response)
 159
 160         return response(environ, start_response)
 161
 162
 163 def paste_app_factory(global_config, **app_config):
 164     mgoblin_app = MediaGoblinApp(app_config['config'])
 165
 166     return mgoblin_app