Add event hook for attaching Rattail config to new requests.

tailbone/subscribers.py

@@ -36,6 +36,35 @@ from rattail.db.model import User
 from rattail.db.auth import has_permission
 
 
+def add_rattail_config_attribute_to_request(event):
+    """
+    Add a ``rattail_config`` attribute to a request object.
+
+    This function is really just a matter of convenience, but it should help to
+    make other code more terse (example below).  It is designed to act as a
+    subscriber to the Pyramid ``NewRequest`` event.
+
+    A global Rattail ``config`` should already be present within the Pyramid
+    application registry's settings, which would normally be accessed via::
+    
+       request.registry.settings['rattail_config']
+
+    This function merely "promotes" this config object so that it is more
+    directly accessible, a la::
+
+       request.rattail_config
+
+    .. note::
+       All this of course assumes that a Rattail ``config`` object *has* in
+       fact already been placed in the application registry settings.  If this
+       is not the case, this function will do nothing.
+    """
+    request = event.request
+    rattail_config = request.registry.settings.get('rattail_config')
+    if rattail_config:
+        request.rattail_config = rattail_config
+
+
 def before_render(event):
     """
     Adds goodies to the global template renderer context.
@@ -96,5 +125,6 @@ def context_found(event):
 
 
 def includeme(config):
+    config.add_subscriber(add_rattail_config_attribute_to_request, 'pyramid.events.NewRequest')
     config.add_subscriber(before_render, 'pyramid.events.BeforeRender')
     config.add_subscriber(context_found, 'pyramid.events.ContextFound')