add signup links to shift list, only show unregisterd shifts

shiftregister/app/templates/shiftlist.html

@@ -5,7 +5,7 @@
 <h2>Freie Scchichten:</h2>
 <ul>
     {% for shift in free_shifts %}
-        <li>{{ shift.room.name }} {{shift.start_at}}<a href="todo reg url">Mithelfen</a></li>
+        <li>{{ shift.room.name }} {{shift.start_at}}<a href="{%url 'shift' shift.id%}">Mithelfen</a></li>
     {% endfor %}
     </ul>
 {% endblock %}

shiftregister/app/views.py

@@ -1,18 +1,25 @@
 from django.shortcuts import render, redirect, get_object_or_404
 from .models import Shift, LoginToken, Helper, ShiftRegistration
 import datetime
-from django.db.models import F, Count
+from django.db.models import F, Count, Q
 from .forms import RegisterForm, EmptyForm
 
 def index(request):
-    del request.session['last_seen_shift']
+    if request.session.get('last_seen_shift'):
+        del request.session['last_seen_shift']
     # dont show shifts starting in <60 minutes?
     # currently only sorts by date
+    context = {}
+    helper = None
+    if request.session.get('token'):
+        helper = LoginToken.objects.get(pk=request.session['token']).helper
+        context['helper'] = helper
     free_shifts = Shift.objects.annotate(reg_count=Count('shiftregistration')).filter(start_at__gt=datetime.datetime.now(),
                     room__required_helpers__gt=F('reg_count')).order_by('start_at')
-    context = {'free_shifts': free_shifts}
-    if request.session.get('token'):
-        context['helper'] = LoginToken.objects.get(pk=request.session['token']).helper
+    if helper:
+        free_shifts = Shift.objects.annotate(reg_count=Count('shiftregistration')).filter(start_at__gt=datetime.datetime.now(),
+                    room__required_helpers__gt=F('reg_count')).filter( ~Q(shiftregistration__helper=helper)).order_by('start_at')
+    context['free_shifts']= free_shifts
     return render(request, 'shiftlist.html', context)
 
 def login(request, token):