make it possible to delete graph nodes again

src/c3nav/editor/static/editor/css/editor.css

@@ -119,6 +119,9 @@ legend {
     right: 8px;
     top: 8px;
 }
+[data-active-node] form button {
+    margin-top: 5px;
+}
 [data-levels], [data-sublevels], #sidebar .nav, [data-modal-close] {
     display:none;
 }

src/c3nav/editor/static/editor/js/editor.js

@@ -259,7 +259,12 @@ editor = {
         var btn = $(this).data('btn');
         if (btn !== undefined && btn !== null) {
             if ($(btn).is('[name]')) {
-                data += '&' + $('<input>').attr('name', $(btn).attr('name')).val($(btn).val()).serialize();
+                var name = $(btn).attr('name');
+                data += '&' + $('<input>').attr('name', name).val($(btn).val()).serialize();
+                if (name === 'delete_confirm') {
+                    editor._active_graph_node = null;
+                    editor._active_graph_node_html = null;
+                }
             }
         }
         var action = $(this).attr('action');

src/c3nav/editor/templates/editor/graph.html

@@ -33,6 +33,11 @@
             {% blocktrans %}in space {{ space_title }}{% endblocktrans %}<br>
             {% blocktrans %}on level {{ level_title }}{% endblocktrans %}
         {% endwith %}
+        <form action="{{ request.path }}" method="post">
+            {% csrf_token %}
+            <input type="hidden" name="pk" value="{{ active_node.pk }}">
+            <button type="submit" class="btn btn-danger btn-xs" name="delete" value="1">{% trans 'Delete Node' %}</button>
+        </form>
     </div>
 {% else %}
     <div data-active-node class="well well-sm"></div>

src/c3nav/editor/views/edit.py

@@ -419,6 +419,27 @@ def graph_edit(request, level=None, space=None):
         create_nodes = True
 
     if request.method == 'POST':
+        if request.POST.get('delete') == '1':
+            # Delete this graphnode!
+            node = get_object_or_404(GraphNode, pk=request.POST.get('pk'))
+
+            if request.POST.get('delete_confirm') == '1':
+                with request.changeset.lock_to_edit(request) as changeset:
+                    if changeset.can_edit(request):
+                        node.edges_from_here.all().delete()
+                        node.edges_to_here.all().delete()
+                        node.delete()
+                    else:
+                        messages.error(request, _('You can not edit changes on this changeset.'))
+                        return redirect(request.path)
+                messages.success(request, _('Graph Node was successfully deleted.'))
+                return redirect(request.path)
+            return render(request, 'editor/delete.html', {
+                'model_title': GraphNode._meta.verbose_name,
+                'pk': node.pk,
+                'obj_title': node.title
+            })
+
         edge_settings_form = GraphEdgeSettingsForm(instance=GraphEdge(), request=request, data=request.POST)
         graph_action_form = GraphEditorActionForm(request=request, allow_clicked_position=create_nodes,
                                                   data=request.POST)