EVOLUTION-MANAGER

Edit File: wipe-evolution.py

from optparse import make_option

from django.core.management.base import BaseCommand, CommandError
from django.db.models import Q

from django_evolution.models import Evolution

class Command(BaseCommand):
    """Wipes an evolutions from the history.

This is a very dangerous operation, and should only be done after a
    full database backup.
    """
    option_list = BaseCommand.option_list + (
        make_option(
            '--noinput', action='store_false', dest='interactive',
            default=True,
            help='Tells Django to NOT prompt the user for input of any kind.'),
        make_option(
            '--app-label', action='store', dest='app_label',
            help='The app label the evolution label applies to.'),
    )

def handle(self, *evolution_labels, **options):
        if not evolution_labels:
            raise CommandError(
                'One or more evolution labels must be provided.')

# Sanity-check each app to make sure it exists only once, and is
        # in the given app (if specified).
        to_wipe_ids = []
        app_label = options['app_label']

for evolution_label in evolution_labels:
            q = Q(label=evolution_label)

if app_label:
                q = q & Q(app_label=app_label)

evolutions = list(Evolution.objects.filter(q).values('pk'))

if len(evolutions) == 0:
                if app_label:
                    raise CommandError(
                        "Unable to find evolution '%s' for app label '%s'" %
                        (evolution_label, app_label))
                else:
                    raise CommandError(
                        "Unable to find evolution '%s'" % evolution_label)
            if len(evolutions) > 1:
                if app_label:
                    raise CommandError(
                        "Too many evolutions named '%s' for app label '%s'" %
                        (evolution_label, app_label))
                else:
                    raise CommandError(
                        "Too many evolutions named '%s'" % evolution_label)

to_wipe_ids.append(evolutions[0]['pk'])

if to_wipe_ids:
            if options['interactive']:
                confirm = raw_input("""
You have requested to delete %s evolution(s). This may cause permanent
problems, and should only be done after a FULL BACKUP and under direct
guidance.

Are you sure you want to wipe these evolutions from the database?

Type 'yes' to continue, or 'no' to cancel: """ % len(to_wipe_ids))
            else:
                confirm = 'yes'

if confirm == 'yes':
                Evolution.objects.filter(pk__in=to_wipe_ids).delete()

print '%s evolution(s) have been deleted.' % len(to_wipe_ids)