Enforce start and end time of presale (#15)

src/pretix/base/models.py

@@ -482,6 +482,20 @@ class Event(Versionable):
         """
         return SettingsProxy(self, type=EventSetting, parent=self.organizer)
 
+    @property
+    def presale_has_ended(self):
+        if self.presale_end and now() > self.presale_end:
+            return True
+        return False
+
+    @property
+    def presale_is_running(self):
+        if self.presale_start and now() < self.presale_start:
+            return False
+        if self.presale_end and now() > self.presale_end:
+            return False
+        return True
+
 
 class EventPermission(Versionable):
     """

src/pretix/base/settings.py

@@ -41,6 +41,14 @@ DEFAULTS = {
         'default': 'True',
         'type': bool
     },
+    'presale_start_show_date': {
+        'default': 'True',
+        'type': bool
+    },
+    'show_items_outside_presale_period': {
+        'default': 'True',
+        'type': bool
+    },
     'timezone': {
         'default': settings.TIME_ZONE,
         'type': str