Restructure the create_permission signal handler to perform fewer SQL queries,...

Creates permissions for all installed apps that need permissions.

"""

from django.db.models import get_models, signals

from django.contrib.auth import models as auth_app

from django.db.models import get_models, signals

def _get_permission_codename(action, opts):

    return u'%s_%s' % (action, opts.object_name.lower())

    from django.contrib.contenttypes.models import ContentType

    app_models = get_models(app)

    # This will hold the permissions we're looking for as

    # (content_type, (codename, name))

    searched_perms = set()

    # The codenames and ctypes that should exist.

    ctypes = set()

    codenames = set()

    for klass in app_models:

        ctype = ContentType.objects.get_for_model(klass)

        for codename, name in _get_all_permissions(klass._meta):

            p, created = auth_app.Permission.objects.get_or_create(

        ctypes.add(ctype)

        for perm in _get_all_permissions(klass._meta):

            codenames.add(perm[0])

            searched_perms.add((ctype, perm))

    # Find all the Permissions that a) have a content_type for a model we're

    # looking for, and b) have a codename we're looking for. It doesn't need to

    # have both, we have a list of exactly what we want, and it's faster to

    # write the query with fewer conditions.

    all_perms = set(auth_app.Permission.objects.filter(

        content_type__in=ctypes,

        codename__in=codenames

    ).values_list(

        "content_type", "codename"

    ))

    for ctype, (codename, name) in searched_perms:

        # If the permissions exists, move on.

        if (ctype.pk, codename) in all_perms:

            continue

        p = auth_app.Permission.objects.create(

            codename=codename,

                content_type__pk=ctype.id,

                defaults={

                    'name': name,

                    'content_type': ctype

                }

            name=name,

            content_type=ctype

        )

            if created and verbosity >= 2:

        if verbosity >= 2:

            print "Adding permission '%s'" % p

def create_superuser(app, created_models, verbosity, **kwargs):

    from django.core.management import call_command