def migration_strings(f):
"""
"""
models, complete_apps = parse_migration(f)
strings = set(complete_apps)
_deep_add(strings, models)
return strings
def squash_migrations(app_to_migration_path):
"""
Squash many initial migrations into a single migration.
`app_to_migration_path` is a dict from app name to the path of the initial
migration for that app.
Returns the squashed migration as a StringIO object.
The squashed migration has:
- no dependencies
- a forwards() function obtained by concatenating the forwards() functions
of all the given migrations
- a backwards() function that raises RuntimeError
- all frozen models in all the given migrations
- all complete_apps in all the given migrations
"""
output = StringIO()
# Write header and start the forwards() method.
print >>output, _imports
print >>output, _class_def
print >>output, _forwards
# In forwards(), concatenate all the forwards() of individual migrations.
for app, migration_path in sorted(app_to_migration_path.items()):
print >>output, "\n ### {} app ###\n".format(app)
output.write(forwards_contents(open(migration_path)))
# Write the backwards() method.
print >>output, _backwards
# Collect all frozen models from individual migrations, and write all of
# them to the new migration.
all_models = {}
for app, migration_path in app_to_migration_path.iteritems():
models, complete_apps = parse_migration(open(migration_path))
if complete_apps != [app]:
raise ValueError("App '{}' has unexpected complete_apps {}.".format(
app, complete_apps))
all_models.update(models)
_pretty_print_models(all_models, output)
# Write complete_apps for the new migration.
_pretty_print_complete_apps(app_to_migration_path.keys(), output)
return output
def make_dummy_migration(app, migration_path, destination_app,
squashed_migration_name):
"""
Make a new initial migration for an app whose initial migration has been
squashed.
`app` is the name of the app for which to create an initial migration.
`migration_path` is the path to the initial migration for that app.
`destination_app` is the app containing the new squashed migration.
`squashed_migration_name` is the name of the squashed migration (without
the '.py' suffix)
Returns the new initial migration as a StringIO object.
The new migration has:
- a dependency on the squashed migration
- a forwards() function that does nothing
- a backwards() function that raises RuntimeError
- all frozen models in the original migration
- the complete_apps in the original migration
"""
output = StringIO()
# Write header, depends_on, dummy forwards, and backwards.
print >>output, _imports
print >>output, _class_def
print >>output, _depends_on.format(destination_app, squashed_migration_name)
print >>output, _forwards
print >>output, " pass"
print >>output, _backwards
# Write the original frozen models and complete_apps for this migration.
models, complete_apps = parse_migration(open(migration_path))
_pretty_print_models(models, output)
_pretty_print_complete_apps(complete_apps, output)
return output
