using flask-migrate with flask-script and application factory -

i'm building flask application , decided try application factory approach time, got trouble flask-migrate , can't figure out simple solution.

please note want pass config location option script

manage.py:

manager = manager(create_app) manager.add_option("-c", "--config", dest="config_module", required=false) 

then need create migrate instance , add command manager:

with manager.app.app_context():     migrate = migrate(current_app, db)     manager.add_command('db', migratecommand) 

but app instance not created yet, fails

i know can pass config in environment variable , create application before creating manager instance, how using manager options?

when use --config option have use application factory function know, function gets config argument , allows create app right configuration.

since have app factory, have use deferred initialization extensions. instantiate extensions without passing arguments, , in app factory function after create application, call init_app on extensions, passing app , db have them.

the migratecommand separate this, can add manager without having app , db instances created.

example:

manage.py:

from app import create_app flask_migrate import migratecommand  manager = manager(create_app) manager.add_option("-c", "--config", dest="config_module", required=false) manager.add_command('db', migratecommand) 

app.py (or app factory module called)

from flask import flask flask_sqlalchemy import sqlalchemy flask_migrate import migrate  db = sqlalchemy() migrate = migrate()  def create_app(config):     app = flask(__name__)     # apply configuration     # ...      # initialize extensions     db.init_app(app)     migrate.init_app(app, db)      return app