Add signal to display html in quota detail view (#264)

doc/development/api/general.rst

@@ -47,7 +47,7 @@ Backend
 -------
 
 .. automodule:: pretix.control.signals
-   :members: nav_event, html_head
+   :members: nav_event, html_head, quota_detail_html
 
 
 .. automodule:: pretix.base.signals

src/pretix/control/signals.py

@@ -94,3 +94,13 @@ You will receive the default form class (or the class set by a previous plugin)
 
 As with all plugin signals, the ``sender`` keyword argument will contain the event.
 """
+
+quota_detail_html = EventPluginSignal(
+    providing_args=['quota']
+)
+"""
+This signal allows you to append HTML to a Quota's detail view. You receive the
+quota as argument in the ``quota`` keyword argument.
+
+As with all plugin signals, the ``sender`` keyword argument will contain the event.
+"""

src/pretix/control/templates/pretixcontrol/items/quota.html

@@ -1,6 +1,7 @@
 {% extends "pretixcontrol/items/base.html" %}
 {% load i18n %}
 {% load bootstrap3 %}
+{% load eventsignal %}
 {% block title %}{% blocktrans with name=quota.name %}Quota: {{ name }}{% endblocktrans %}{% endblock %}
 {% block inside %}
     <h1>
@@ -54,4 +55,5 @@
             </div>
         </div>
     </div>
+    {% eventsignal request.event "pretix.control.signals.quota_detail_html" quota=quota %}
 {% endblock %}