Navigation and dashboard: Hide useless items (#5995)

* Navigation and dashboard: Hide useless items

If a user has access to *no organizer teams*, hide a number of things
from navigation and dashboard. This happens e.g. if a user only has
permissions in scope of the pretix-resellers or pretix-scheduling
plugins.

* New mechanism

src/pretix/base/models/auth.py

@@ -49,6 +49,7 @@ from django.core.exceptions import BadRequest, PermissionDenied
 from django.db import IntegrityError, models, transaction
 from django.db.models import Q
 from django.utils.crypto import get_random_string, salted_hmac
+from django.utils.functional import cached_property
 from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 from django_otp.models import Device
@@ -667,6 +668,11 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
         self.session_token = generate_session_token()
         self.save(update_fields=['session_token'])
 
+    @cached_property
+    @scopes_disabled()
+    def is_in_any_teams(self):
+        return self.teams.exists()
+
 
 class UserKnownLoginSource(models.Model):
     user = models.ForeignKey('User', on_delete=models.CASCADE, related_name="known_login_sources")

src/pretix/control/navigation.py

@@ -340,6 +340,9 @@ def get_global_navigation(request):
             'active': (url.url_name == 'index'),
             'icon': 'dashboard',
         },
+    ]
+    if request.user.is_in_any_teams:
+        nav += [
             {
                 'label': _('Events'),
                 'url': reverse('control:events'),
@@ -372,6 +375,8 @@ def get_global_navigation(request):
                     },
                 ]
             },
+        ]
+    nav += [
         {
             'label': _('User settings'),
             'url': reverse('control:user.settings'),

src/pretix/control/templates/pretixcontrol/dashboard.html

@@ -12,6 +12,7 @@
                 class="event-dropdown dropdown-menu">
         </ul>
     </div>
+    {% if upcoming or can_create_event %}
         <h2>{% trans "Your upcoming events" %}</h2>
         <div class="dashboard">
             {% if can_create_event %}
@@ -33,6 +34,7 @@
                 </div>
             {% endfor %}
         </div>
+    {% endif %}
     {% if upcoming %}
         <p class="">
             <a href="{% url "control:events" %}?ordering=date_from&status=date_future" class="">