Include Forum deletion facilities

forums/templates/forums/forum_confirm_delete.html

+{% extends 'forums/base.html' %}
+
+{% load bootstrap %}
+
+{% block pagetitle %}: Delete Forum{% endblock pagetitle %}
+
+{% block content %}
+<div class="row">
+    <div class="col-12">
+        <h1 class="highlight">Delete Forum</h1>
+	{{ object }}
+    </div>
+</div>
+<div class="row">
+  <div class="col-12">
+    <form method="post">
+      {% csrf_token %}
+      <h3 class="mb-2">Are you sure you want to delete this Forum (and all associated Posts)?</h3>
+      <input type="submit" class="btn btn-danger" value="Yes, delete it" />
+    </form>
+  </div>
+</div>
+
+{% endblock content %}

forums/templates/forums/forum_detail.html

@@ -19,9 +19,24 @@
   <div class="col-12">
     <h3 class="highlight">{{ forum.name }}</h3>
 
+    {% if forum.parent %}
+    <p>Parent: <a href="{{ forum.parent.get_absolute_url }}">{{ forum.parent }}</a></p>
+    {% endif %}
+    {% if forum.child_forums.all|length > 0 %}
+    <p>Descendants: {% for child in forum.child_forums.all %}<a href="{{ child.get_absolute_url }}">{{ child }}</a>{% if not forloop.last %}, {% endif %}{% endfor %}</p>
+    {% endif %}
+
     {% if perms.forums.add_forum or "can_change_forum" in user_perms %}
+    <h4>Admin actions:</h4>
     <ul>
       <li><a href="{% url 'forums:forum_create' parent_model='forum' parent_id=forum.id %}">Create a (sub)Forum within this one</a></li>
+      <li>
+	{% if not forum.child_forums %}
+	<a href="{% url 'forums:forum_delete' slug=forum.slug %}" class="text-danger">Delete this Forum (and all Posts it contains)</a>
+	{% else %}
+	<span class="text-danger" style="text-decoration: line-through;">Delete this Forum</span> Please delete descendant Forums first.
+	{% endif %}
+      </li>
     </ul>
 
     <div class="card">

forums/urls.py

@@ -22,6 +22,11 @@ urlpatterns = [
         views.ForumDetailView.as_view(),
         name='forum_detail'
     ),
+    url(
+        r'^(?P<slug>[\w-]+)/delete/$',
+        views.ForumDeleteView.as_view(),
+        name='forum_delete'
+    ),
     url(
         r'^(?P<slug>[\w-]+)/permissions/(?P<group_id>[0-9]+)/$',
         views.ForumPermissionsView.as_view(),

forums/views.py

@@ -2,16 +2,17 @@ __copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
 __license__ = "AGPL v3"
 
 
+from django.contrib import messages
 from django.contrib.auth.models import Group
 from django.contrib.auth.mixins import UserPassesTestMixin
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import PermissionDenied
 from django.core.urlresolvers import reverse_lazy
 from django.http import Http404
-from django.shortcuts import get_object_or_404
+from django.shortcuts import get_object_or_404, redirect
 from django.utils import timezone
 from django.views.generic.detail import DetailView
-from django.views.generic.edit import CreateView, UpdateView
+from django.views.generic.edit import CreateView, UpdateView, DeleteView
 from django.views.generic.list import ListView
 
 from guardian.mixins import PermissionRequiredMixin
@@ -46,6 +47,28 @@ class ForumCreateView(PermissionsMixin, CreateView):
         return initial
 
 
+class ForumDeleteView(PermissionRequiredMixin, DeleteView):
+    permission_required = 'forums.delete_forum'
+    model = Forum
+    success_url = reverse_lazy('forums:forums')
+
+    def delete(self, request, *args, **kwargs):
+        """
+        A Forum can only be deleted if it does not have any descendants.
+        Upon deletion, all object-level permissions associated to the
+        Forum are explicitly removed.
+        """
+        forum = get_object_or_404(Forum, slug=self.kwargs.get('slug'))
+        groups_perms_dict = get_groups_with_perms(forum, attach_perms=True)
+        if forum.child_forums.all().count() > 0:
+            messages.warning(request, 'A Forum with descendants cannot be deleted.')
+            return redirect(forum.get_absolute_url())
+        for group, perms_list in groups_perms_dict.items():
+            for perm in perms_list:
+                remove_perm(perm, group, forum)
+        return super().delete(request, *args, **kwargs)
+
+
 class ForumDetailView(PermissionRequiredMixin, DetailView):
     permission_required = 'forums.can_view_forum'
     model = Forum

organizations/views.py

@@ -8,7 +8,8 @@ from django.contrib.auth.mixins import UserPassesTestMixin
 from django.core.exceptions import PermissionDenied
 from django.core.urlresolvers import reverse_lazy
 from django.db import transaction
-from django.shortcuts import get_object_or_404, render, reverse, redirect
+from django.shortcuts import get_object_or_404, render, redirect
+from django.urls import reverse
 from django.utils import timezone
 from django.views.generic.detail import DetailView
 from django.views.generic.edit import CreateView, UpdateView, DeleteView