debian-south/south/management/commands/schemamigration.py

230 lines
10 KiB
Python

"""
Startmigration command, version 2.
"""
from __future__ import print_function
import sys
import os
import re
import string
import random
import inspect
from optparse import make_option
try:
set
except NameError:
from sets import Set as set
from django.core.management.base import BaseCommand
from django.core.management.color import no_style
from django.core.exceptions import ImproperlyConfigured
from django.db import models
from django.conf import settings
from south.migration import Migrations, migrate_app
from south.models import MigrationHistory
from south.exceptions import NoMigrations
from south.creator import changes, actions, freezer
from south.management.commands.datamigration import Command as DataCommand
class Command(DataCommand):
option_list = DataCommand.option_list + (
make_option('--add-model', action='append', dest='added_model_list', type='string',
help='Generate a Create Table migration for the specified model. Add multiple models to this migration with subsequent --add-model parameters.'),
make_option('--add-field', action='append', dest='added_field_list', type='string',
help='Generate an Add Column migration for the specified modelname.fieldname - you can use this multiple times to add more than one column.'),
make_option('--add-index', action='append', dest='added_index_list', type='string',
help='Generate an Add Index migration for the specified modelname.fieldname - you can use this multiple times to add more than one column.'),
make_option('--initial', action='store_true', dest='initial', default=False,
help='Generate the initial schema for the app.'),
make_option('--auto', action='store_true', dest='auto', default=False,
help='Attempt to automatically detect differences from the last migration.'),
make_option('--empty', action='store_true', dest='empty', default=False,
help='Make a blank migration.'),
make_option('--update', action='store_true', dest='update', default=False,
help='Update the most recent migration instead of creating a new one. Rollback this migration if it is already applied.'),
)
help = "Creates a new template schema migration for the given app"
usage_str = "Usage: ./manage.py schemamigration appname migrationname [--empty] [--initial] [--auto] [--add-model ModelName] [--add-field ModelName.field_name] [--stdout]"
def handle(self, app=None, name="", added_model_list=None, added_field_list=None, freeze_list=None, initial=False, auto=False, stdout=False, added_index_list=None, verbosity=1, empty=False, update=False, **options):
# Any supposed lists that are None become empty lists
added_model_list = added_model_list or []
added_field_list = added_field_list or []
added_index_list = added_index_list or []
freeze_list = freeze_list or []
# --stdout means name = -
if stdout:
name = "-"
# Only allow valid names
if re.search('[^_\w]', name) and name != "-":
self.error("Migration names should contain only alphanumeric characters and underscores.")
# Make sure options are compatable
if initial and (added_model_list or added_field_list or auto):
self.error("You cannot use --initial and other options together\n" + self.usage_str)
if auto and (added_model_list or added_field_list or initial):
self.error("You cannot use --auto and other options together\n" + self.usage_str)
if not app:
self.error("You must provide an app to create a migration for.\n" + self.usage_str)
# See if the app exists
app = app.split(".")[-1]
try:
app_module = models.get_app(app)
except ImproperlyConfigured:
print("There is no enabled application matching '%s'." % app)
return
# Get the Migrations for this app (creating the migrations dir if needed)
migrations = Migrations(app, force_creation=True, verbose_creation=int(verbosity) > 0)
# What actions do we need to do?
if auto:
# Get the old migration
try:
last_migration = migrations[-2 if update else -1]
except IndexError:
self.error("You cannot use --auto on an app with no migrations. Try --initial.")
# Make sure it has stored models
if migrations.app_label() not in getattr(last_migration.migration_class(), "complete_apps", []):
self.error("You cannot use automatic detection, since the previous migration does not have this whole app frozen.\nEither make migrations using '--freeze %s' or set 'SOUTH_AUTO_FREEZE_APP = True' in your settings.py." % migrations.app_label())
# Alright, construct two model dicts to run the differ on.
old_defs = dict(
(k, v) for k, v in last_migration.migration_class().models.items()
if k.split(".")[0] == migrations.app_label()
)
new_defs = dict(
(k, v) for k, v in freezer.freeze_apps([migrations.app_label()]).items()
if k.split(".")[0] == migrations.app_label()
)
change_source = changes.AutoChanges(
migrations = migrations,
old_defs = old_defs,
old_orm = last_migration.orm(),
new_defs = new_defs,
)
elif initial:
# Do an initial migration
change_source = changes.InitialChanges(migrations)
else:
# Read the commands manually off of the arguments
if (added_model_list or added_field_list or added_index_list):
change_source = changes.ManualChanges(
migrations,
added_model_list,
added_field_list,
added_index_list,
)
elif empty:
change_source = None
else:
print("You have not passed any of --initial, --auto, --empty, --add-model, --add-field or --add-index.", file=sys.stderr)
sys.exit(1)
# Validate this so we can access the last migration without worrying
if update and not migrations:
self.error("You cannot use --update on an app with no migrations.")
# if not name, there's an error
if not name:
if change_source:
name = change_source.suggest_name()
if update:
name = re.sub(r'^\d{4}_', '', migrations[-1].name())
if not name:
self.error("You must provide a name for this migration\n" + self.usage_str)
# Get the actions, and then insert them into the actions lists
forwards_actions = []
backwards_actions = []
if change_source:
for action_name, params in change_source.get_changes():
# Run the correct Action class
try:
action_class = getattr(actions, action_name)
except AttributeError:
raise ValueError("Invalid action name from source: %s" % action_name)
else:
action = action_class(**params)
action.add_forwards(forwards_actions)
action.add_backwards(backwards_actions)
print(action.console_line(), file=sys.stderr)
# Nowt happen? That's not good for --auto.
if auto and not forwards_actions:
self.error("Nothing seems to have changed.")
# Work out which apps to freeze
apps_to_freeze = self.calc_frozen_apps(migrations, freeze_list)
# So, what's in this file, then?
file_contents = self.get_migration_template() % {
"forwards": "\n".join(forwards_actions or [" pass"]),
"backwards": "\n".join(backwards_actions or [" pass"]),
"frozen_models": freezer.freeze_apps_to_string(apps_to_freeze),
"complete_apps": apps_to_freeze and "complete_apps = [%s]" % (", ".join(map(repr, apps_to_freeze))) or ""
}
# Deal with update mode as late as possible, avoid a rollback as long
# as something else can go wrong.
if update:
last_migration = migrations[-1]
if MigrationHistory.objects.filter(applied__isnull=False, app_name=app, migration=last_migration.name()):
print("Migration to be updated, %s, is already applied, rolling it back now..." % last_migration.name(), file=sys.stderr)
migrate_app(migrations, 'current-1', verbosity=verbosity)
for ext in ('py', 'pyc'):
old_filename = "%s.%s" % (os.path.join(migrations.migrations_dir(), last_migration.filename), ext)
if os.path.isfile(old_filename):
os.unlink(old_filename)
migrations.remove(last_migration)
# See what filename is next in line. We assume they use numbers.
new_filename = migrations.next_filename(name)
# - is a special name which means 'print to stdout'
if name == "-":
print(file_contents)
# Write the migration file if the name isn't -
else:
fp = open(os.path.join(migrations.migrations_dir(), new_filename), "w")
fp.write(file_contents)
fp.close()
verb = 'Updated' if update else 'Created'
if empty:
print("%s %s. You must now edit this migration and add the code for each direction." % (verb, new_filename), file=sys.stderr)
else:
print("%s %s. You can now apply this migration with: ./manage.py migrate %s" % (verb, new_filename, app), file=sys.stderr)
def get_migration_template(self):
return MIGRATION_TEMPLATE
MIGRATION_TEMPLATE = """# -*- coding: utf-8 -*-
from south.utils import datetime_utils as datetime
from south.db import db
from south.v2 import SchemaMigration
from django.db import models
class Migration(SchemaMigration):
def forwards(self, orm):
%(forwards)s
def backwards(self, orm):
%(backwards)s
models = %(frozen_models)s
%(complete_apps)s"""