from django.apps import apps


def get_permission_change_data(sender, permissions, **kwargs):
    """
    Yields all necessary collections from the topics app if
    'agenda.can_see' permission changes, because topics are strongly
    connected to the agenda items.
    """
    topics_app = apps.get_app_config(app_label='topics')
    for permission in permissions:
        # There could be only one 'agenda.can_see' and then we want to return data.
        if permission.content_type.app_label == 'agenda' and permission.codename == 'can_see':
            yield from topics_app.get_startup_elements()