Moved app.load_controller -> util.import_component and added tests.

mediagoblin/app.py

@@ -14,10 +14,8 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
 import urllib
 
-from beaker.middleware import SessionMiddleware
 import routes
 import mongokit
 from webob import Request, exc
@@ -29,14 +27,6 @@ class Error(Exception): pass
 class ImproperlyConfigured(Error): pass
 
 
-def load_controller(string):
-    module_name, func_name = string.split(':', 1)
-    __import__(module_name)
-    module = sys.modules[module_name]
-    func = getattr(module, func_name)
-    return func
-
-
 class MediaGoblinApp(object):
     """
     Really basic wsgi app using routes and WebOb.
@@ -71,7 +61,7 @@ class MediaGoblinApp(object):
             # Okay, no matches.  404 time!
             return exc.HTTPNotFound()(environ, start_response)
 
-        controller = load_controller(route_match['controller'])
+        controller = util.import_component(route_match['controller'])
         request.start_response = start_response
 
         request.matchdict = route_match
@@ -87,9 +77,13 @@ class MediaGoblinApp(object):
 
 
 def paste_app_factory(global_config, **kw):
+    # Get the database connection
     connection = mongokit.Connection(
         kw.get('db_host'), kw.get('db_port'))
 
+    # Set up the storage systems.
+    ## TODO: allow for extra storage systems that aren't just
+    ## BasicFileStorage.
     mgoblin_app = MediaGoblinApp(
         connection, kw.get('db_name', 'mediagoblin'),
         user_template_path=kw.get('local_templates'))

mediagoblin/tests/test_util.py

@@ -0,0 +1,30 @@
+# GNU MediaGoblin -- federated, autonomous media hosting
+# Copyright (C) 2011 Free Software Foundation, Inc
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from mediagoblin import util
+
+
+def _import_component_testing_method(silly_string):
+    # Just for the sake of testing that our component importer works.
+    return u"'%s' is the silliest string I've ever seen" % silly_string
+
+
+def test_import_component():
+    imported_func = util.import_component(
+        'mediagoblin.tests.test_util:_import_component_testing_method')
+    result = imported_func('hooobaladoobala')
+    expected = u"'hooobaladoobala' is the silliest string I've ever seen"
+    assert result == expected

mediagoblin/util.py

@@ -14,6 +14,8 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
+
 import jinja2
 import mongokit
 
@@ -54,3 +56,19 @@ def setup_user_in_request(request):
         request.session.invalidate()
 
     request.user = user
+
+
+def import_component(import_string):
+    """
+    Import a module component defined by STRING.  Probably a method,
+    class, or global variable.
+
+    Args:
+     - import_string: a string that defines what to import.  Written
+       in the format of "module1.module2:component"
+    """
+    module_name, func_name = import_string.split(':', 1)
+    __import__(module_name)
+    module = sys.modules[module_name]
+    func = getattr(module, func_name)
+    return func