Added process_response URL hook

doc/development/api/general.rst

@@ -35,7 +35,7 @@ Request flow
 """"""""""""
 
 .. automodule:: pretix.presale.signals
-   :members: process_request
+   :members: process_request, process_response
 
 Vouchers
 """"""""

src/pretix/presale/middleware.py

@@ -1,5 +1,7 @@
 from django.core.urlresolvers import resolve
 
+from pretix.presale.signals import process_response
+
 from .utils import _detect_event
 
 
@@ -19,3 +21,8 @@ class EventMiddleware:
             # We need to create session even if we do not yet store something there, because we need the session
             # key for e.g. saving the user's cart
             request.session['_'] = '_'
+
+    def process_response(self, request, response):
+        for receiver, r in process_response.send(request.event, request=request, response=response):
+            response = r
+        return response

src/pretix/presale/signals.py

@@ -52,7 +52,7 @@ process_request = EventPluginSignal(
 """
 This signal is sent out whenever a request is made to a event presale page. Most of the
 time, this will be called from the middleware layer (except on plugin-provided pages
-this will be caled by the @event_view decorator). Similarly to Django's process_request
+this will be called by the @event_view decorator). Similarly to Django's process_request
 middleware method, if you return a Response, that response will be used and the request
 won't be processed any further down the stack.
 
@@ -61,3 +61,20 @@ easy to cause serious performance problems.
 
 As with all plugin signals, the ``sender`` keyword argument will contain the event.
 """
+
+process_response = EventPluginSignal(
+    providing_args=["request", "response"]
+)
+"""
+This signal is sent out whenever a response is sent from a event presale page. Most of
+the time, this will be called from the middleware layer (except on plugin-provided pages
+this will be called by the @event_view decorator). Similarly to Django's process_response
+middleware method you must return a response object, that will be passed further up the
+stack to other handlers of the signal. If you do not want to alter the response, just
+return the ``response`` parameter.
+
+WARNING: Be very careful about using this signal as listening to it makes it really
+easy to cause serious performance problems.
+
+As with all plugin signals, the ``sender`` keyword argument will contain the event.
+"""

src/pretix/presale/utils.py

@@ -9,7 +9,7 @@ from django.utils.translation import ugettext_lazy as _
 from pretix.base.middleware import LocaleMiddleware
 from pretix.base.models import Event, EventPermission, Organizer
 from pretix.multidomain.urlreverse import get_domain
-from pretix.presale.signals import process_request
+from pretix.presale.signals import process_request, process_response
 
 
 def _detect_event(request):
@@ -80,5 +80,8 @@ def event_view(func):
         if ret:
             return ret
         else:
-            return func(request=request, *args, **kwargs)
+            response = func(request=request, *args, **kwargs)
+            for receiver, r in process_response.send(request.event, request=request, response=response):
+                response = r
+            return response
     return wrap