Group-Based Features

Group-based feature toggles allow developers to show or hide features based on a user's membership in Django groups. This system is used for alpha/beta testing, gradual rollouts, and access control.

Implementation

The feature toggle system uses a custom Django template filter that checks group membership.

Template Tag

The in_group filter is defined in core/templatetags/group_tags.py:

@register.filter
def in_group(user, group_name):
    """Check if a user is in a specific group by name."""
    if not user or not user.is_authenticated:
        return False

    try:
        group = Group.objects.get(name=group_name)
        return user.groups.filter(pk=group.pk).exists()
    except Group.DoesNotExist:
        return False

Usage in Templates

Load the template tag library:

<div data-gb-custom-block data-tag="load"></div>

Check group membership:

<div data-gb-custom-block data-tag="if" data-0='Campaigns Alpha'>

    <!-- Content only visible to group members -->

</div>

Examples

Navigation Items

<div data-gb-custom-block data-tag="if" data-0='Campaigns Alpha'>

    <li class="nav-item">
        <a class="nav-link

<div data-gb-custom-block data-tag="active_view" data-0='core:campaigns'></div>"
           href="<div data-gb-custom-block data-tag="url" data-0='core:campaigns'></div>

">Campaigns</a>
    </li>

</div>

Feature Sections

<div data-gb-custom-block data-tag="if" data-0='Beta Features'>

    <div class="card">
        <h2>Beta Features</h2>
        <!-- Beta content -->
    </div>

</div>

Conditional Elements

<div data-gb-custom-block data-tag="if" data-0='Premium Users'>

    <button class="btn btn-primary">Advanced Export</button>

<div data-gb-custom-block data-tag="else"></div>

    <button class="btn btn-secondary" disabled>
        Advanced Export (Premium Only)
    </button>

</div>

Managing Groups

Creating Groups

Via Django Admin:

1. Navigate to /admin/auth/group/

2. Click "Add Group"

3. Enter group name

4. Save

Via Django Shell:

from django.contrib.auth.models import Group
Group.objects.create(name="Feature Group Name")

Via Data Migration:

def create_groups(apps, schema_editor):
    Group = apps.get_model('auth', 'Group')
    Group.objects.create(name="Campaigns Alpha")

Adding Users to Groups

Via Django Admin:

1. Navigate to user's detail page

2. Select groups in "Groups" field

3. Save

Via Django Shell:

from django.contrib.auth.models import User, Group
user = User.objects.get(username="username")
group = Group.objects.get(name="Campaigns Alpha")
user.groups.add(group)

Testing

Test group membership in unit tests:

def test_feature_visible_to_group_members(self):
    user = User.objects.create_user(username="test")
    group = Group.objects.create(name="Test Feature")
    user.groups.add(group)

    response = self.client.get('/feature-url/')
    self.assertContains(response, "Feature Content")

Current Feature Groups

Group Name	Purpose	Features
Campaigns Alpha	Early access to campaign features	Campaign navigation link, campaign creation

Best Practices

1. Descriptive Names: Use clear group names like "Campaigns Alpha", "Beta Testers"

2. Document Groups: Maintain a list of active groups and their purposes

3. Fail Safe: The filter returns False for non-existent groups

4. Clean Up: Remove groups after features are fully released

5. Test Coverage: Include tests for both group members and non-members

Security Considerations

• Group membership is checked server-side

• Template filter prevents rendering, not just hiding with CSS

• Groups should not be used for critical security permissions

• Use Django's permission system for access control

Performance

The in_group filter:

• Makes one database query per check

• Results are not cached by default

• Consider using select_related('groups') for user queries if checking many groups