add button for non-owner members to leave group

bookwyrm/templates/groups/group.html

@@ -10,8 +10,9 @@
 
         {% block searchresults %}
         {% endblock %}
-
-        {% include "groups/members.html"  with group=group %}
+        <div class="mb-2">
+          {% include "groups/members.html"  with group=group %}
+        </div>
 
         <h2 class="title is-5">Lists</h2>
         {% if not lists %}

bookwyrm/templates/groups/members.html

@@ -2,6 +2,7 @@
 {% load utilities %}
 {% load humanize %}
 {% load bookwyrm_tags %}
+{% load bookwyrm_group_tags %}
 
 <h2 class="title is-5">Group Members</h2>
 <p class="subtitle is-6">{% trans "Members can add and remove books on a group's book lists" %}</p>
@@ -29,4 +30,19 @@
     </div>
     {% endwith %}
     {% endfor %}
-  </div>
+  </div>
+
+{% if group.user != request.user and group|is_member:request.user %}
+<form action="{% url 'remove-group-member' %}" method="POST" class="my-4">
+    {% csrf_token %}
+    <input type="hidden" name="group" value="{{ group.id }}">
+    <input type="hidden" name="user" value="{{ user.username }}">
+    <button class="button is-small is-danger is-light" type="submit">
+      {% if show_username %}
+      {% blocktrans with username=user.localname %}Remove @{{ username }}{% endblocktrans %}
+      {% else %}
+      {% trans "Remove self from group" %}
+      {% endif %}
+  </button>
+</form>
+{% endif %}

bookwyrm/views/group.py

@@ -194,7 +194,7 @@ def remove_member(request):
 
         memberships = models.GroupMember.objects.filter(group=group)
         model = apps.get_model("bookwyrm.Notification", require_ready=True)
-        notification_type = "LEAVE" if "self_removal" in request.POST and request.POST["self_removal"] else "REMOVE"
+        notification_type = "LEAVE" if user == request.user else "REMOVE"
         # let the other members know about it
         for membership in memberships:
             member = membership.user