django1/django/core/management/commands/makemigrations.py

88 lines
3.8 KiB
Python

import sys
import os
from optparse import make_option
from django.core.management.base import BaseCommand
from django.core.exceptions import ImproperlyConfigured
from django.db import connections, DEFAULT_DB_ALIAS
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.autodetector import MigrationAutodetector, InteractiveMigrationQuestioner
from django.db.migrations.state import ProjectState
from django.db.migrations.writer import MigrationWriter
from django.db.models.loading import cache
class Command(BaseCommand):
option_list = BaseCommand.option_list + (
make_option('--empty', action='store_true', dest='empty', default=False,
help='Make a blank migration.'),
)
help = "Creates new migration(s) for apps."
usage_str = "Usage: ./manage.py makemigrations [--empty] [app [app ...]]"
def handle(self, *app_labels, **options):
self.verbosity = int(options.get('verbosity'))
self.interactive = options.get('interactive')
# Make sure the app they asked for exists
app_labels = set(app_labels)
bad_app_labels = set()
for app_label in app_labels:
try:
cache.get_app(app_label)
except ImproperlyConfigured:
bad_app_labels.add(app_label)
if bad_app_labels:
for app_label in bad_app_labels:
self.stderr.write("App '%s' could not be found. Is it in INSTALLED_APPS?" % app_label)
sys.exit(2)
# Load the current graph state. Takes a connection, but it's not used
# (makemigrations doesn't look at the database state).
loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
# Detect changes
autodetector = MigrationAutodetector(
loader.graph.project_state(),
ProjectState.from_app_cache(cache),
InteractiveMigrationQuestioner(specified_apps=app_labels),
)
changes = autodetector.changes(graph=loader.graph, trim_to_apps=app_labels or None)
# No changes? Tell them.
if not changes and self.verbosity >= 1:
if len(app_labels) == 1:
self.stdout.write("No changes detected in app '%s'" % app_labels.pop())
elif len(app_labels) > 1:
self.stdout.write("No changes detected in apps '%s'" % ("', '".join(app_labels)))
else:
self.stdout.write("No changes detected")
return
directory_created = {}
for app_label, migrations in changes.items():
if self.verbosity >= 1:
self.stdout.write(self.style.MIGRATE_HEADING("Migrations for '%s':" % app_label) + "\n")
for migration in migrations:
# Describe the migration
writer = MigrationWriter(migration)
if self.verbosity >= 1:
self.stdout.write(" %s:\n" % (self.style.MIGRATE_LABEL(writer.filename),))
for operation in migration.operations:
self.stdout.write(" - %s\n" % operation.describe())
# Write it
migrations_directory = os.path.dirname(writer.path)
if not directory_created.get(app_label, False):
if not os.path.isdir(migrations_directory):
os.mkdir(migrations_directory)
init_path = os.path.join(migrations_directory, "__init__.py")
if not os.path.isfile(init_path):
open(init_path, "w").close()
# We just do this once per app
directory_created[app_label] = True
migration_string = writer.as_string()
with open(writer.path, "wb") as fh:
fh.write(migration_string)