class FlaskDB(object):
"""
Convenience wrapper for configuring a Peewee database for use with a Flask
application. Provides a base `Model` class and registers handlers to manage
the database connection during the request/response cycle.
Usage::
from flask import Flask
from peewee import *
from playhouse.flask_utils import FlaskDB
# The database can be specified using a database URL, or you can pass a
# Peewee database instance directly:
DATABASE = 'postgresql:///my_app'
DATABASE = PostgresqlDatabase('my_app')
# If we do not want connection-management on any views, we can specify
# the view names using FLASKDB_EXCLUDED_ROUTES. The db connection will
# not be opened/closed automatically when these views are requested:
FLASKDB_EXCLUDED_ROUTES = ('logout',)
app = Flask(__name__)
app.config.from_object(__name__)
# Now we can configure our FlaskDB:
flask_db = FlaskDB(app)
# Or use the "deferred initialization" pattern:
flask_db = FlaskDB()
flask_db.init_app(app)
# The `flask_db` provides a base Model-class for easily binding models
# to the configured database:
class User(flask_db.Model):
email = CharField()
"""
def __init__(self,
app=None,
database=None,
model_class=Model,
excluded_routes=None):
self.database = None # Reference to actual Peewee database instance.
self.base_model_class = model_class
self._app = app
self._db = database # dict, url, Database, or None (default).
self._excluded_routes = excluded_routes or ()
if app is not None:
self.init_app(app)
def init_app(self, app):
self._app = app
if self._db is None:
if 'DATABASE' in app.config:
initial_db = app.config['DATABASE']
elif 'DATABASE_URL' in app.config:
initial_db = app.config['DATABASE_URL']
else:
raise ValueError('Missing required configuration data for '
'database: DATABASE or DATABASE_URL.')
else:
initial_db = self._db
if 'FLASKDB_EXCLUDED_ROUTES' in app.config:
self._excluded_routes = app.config['FLASKDB_EXCLUDED_ROUTES']
self._load_database(app, initial_db)
self._register_handlers(app)
def _load_database(self, app, config_value):
if isinstance(config_value, Database):
database = config_value
elif isinstance(config_value, dict):
database = self._load_from_config_dict(dict(config_value))
else:
# Assume a database connection URL.
database = db_url_connect(config_value)
if isinstance(self.database, Proxy):
self.database.initialize(database)
else:
self.database = database
def _load_from_config_dict(self, config_dict):
try:
name = config_dict.pop('name')
engine = config_dict.pop('engine')
except KeyError:
raise RuntimeError('DATABASE configuration must specify a '
'`name` and `engine`.')
if '.' in engine:
path, class_name = engine.rsplit('.', 1)
else:
path, class_name = 'peewee', engine
try:
__import__(path)
module = sys.modules[path]
database_class = getattr(module, class_name)
assert issubclass(database_class, Database)
except ImportError:
raise RuntimeError('Unable to import %s' % engine)
except AttributeError:
raise RuntimeError('Database engine not found %s' % engine)
except AssertionError:
raise RuntimeError('Database engine not a subclass of '
'peewee.Database: %s' % engine)
return database_class(name, **config_dict)
def _register_handlers(self, app):
app.before_request(self.connect_db)
app.teardown_request(self.close_db)
def get_model_class(self):
if self.database is None:
raise RuntimeError('Database must be initialized.')
class BaseModel(self.base_model_class):
class Meta:
database = self.database
return BaseModel
@property
def Model(self):
if self._app is None:
database = getattr(self, 'database', None)
if database is None:
self.database = Proxy()
if not hasattr(self, '_model_class'):
self._model_class = self.get_model_class()
return self._model_class
def connect_db(self):
if self._excluded_routes and request.endpoint in self._excluded_routes:
return
self.database.connect()
def close_db(self, exc):
if self._excluded_routes and request.endpoint in self._excluded_routes:
return
if not self.database.is_closed():
self.database.close()
class FlaskDB(object):
def __init__(self, app=None, database=None):
self.database = None # Reference to actual Peewee database instance.
self._app = app
self._db = database # dict, url, Database, or None (default).
if app is not None:
self.init_app(app)
def init_app(self, app):
self._app = app
if self._db is None:
if 'DATABASE' in app.config:
initial_db = app.config['DATABASE']
elif 'DATABASE_URL' in app.config:
initial_db = app.config['DATABASE_URL']
else:
raise ValueError('Missing required configuration data for '
'database: DATABASE or DATABASE_URL.')
else:
initial_db = self._db
self._load_database(app, initial_db)
self._register_handlers(app)
def _load_database(self, app, config_value):
if isinstance(config_value, Database):
database = config_value
elif isinstance(config_value, dict):
database = self._load_from_config_dict(dict(config_value))
else:
# Assume a database connection URL.
database = db_url_connect(config_value)
if isinstance(self.database, Proxy):
self.database.initialize(database)
else:
self.database = database
def _load_from_config_dict(self, config_dict):
try:
name = config_dict.pop('name')
engine = config_dict.pop('engine')
except KeyError:
raise RuntimeError('DATABASE configuration must specify a '
'`name` and `engine`.')
if '.' in engine:
path, class_name = engine.rsplit('.', 1)
else:
path, class_name = 'peewee', engine
try:
__import__(path)
module = sys.modules[path]
database_class = getattr(module, class_name)
assert issubclass(database_class, Database)
except ImportError:
raise RuntimeError('Unable to import %s' % engine)
except AttributeError:
raise RuntimeError('Database engine not found %s' % engine)
except AssertionError:
raise RuntimeError('Database engine not a subclass of '
'peewee.Database: %s' % engine)
return database_class(name, **config_dict)
def _register_handlers(self, app):
app.before_request(self.connect_db)
app.teardown_request(self.close_db)
def get_model_class(self):
if self.database is None:
raise RuntimeError('Database must be initialized.')
class BaseModel(Model):
class Meta:
database = self.database
return BaseModel
@property
def Model(self):
if self._app is None:
database = getattr(self, 'database', None)
if database is None:
self.database = Proxy()
if not hasattr(self, '_model_class'):
self._model_class = self.get_model_class()
return self._model_class
def connect_db(self):
self.database.connect()
def close_db(self, exc):
if not self.database.is_closed():
self.database.close()
class FlaskDB(object):
def __init__(self, app=None):
self._app = app
self.database = None
if app is not None:
self.init_app(app)
def init_app(self, app):
self._app = app
self._load_database(app)
self._register_handlers(app)
def _load_database(self, app):
config_value = app.config['DATABASE']
if isinstance(config_value, dict):
database = self._load_from_config_dict(dict(config_value))
else:
# Assume a database connection URL.
database = db_url_connect(config_value)
if isinstance(self.database, Proxy):
self.database.initialize(database)
else:
self.database = database
def _load_from_config_dict(self, config_dict):
try:
name = config_dict.pop('name')
engine = config_dict.pop('engine')
except KeyError:
raise RuntimeError('DATABASE configuration must specify a '
'`name` and `engine`.')
if '.' in engine:
path, class_name = engine.rsplit('.', 1)
else:
path, class_name = 'peewee', engine
try:
__import__(path)
module = sys.modules[path]
database_class = getattr(module, class_name)
assert issubclass(database_class, _Database)
except ImportError:
raise RuntimeError('Unable to import %s' % engine)
except AttributeError:
raise RuntimeError('Database engine not found %s' % engine)
except AssertionError:
raise RuntimeError('Database engine not a subclass of '
'peewee.Database: %s' % engine)
return database_class(name, **config_dict)
def _register_handlers(self, app):
app.before_request(self.connect_db)
app.teardown_request(self.close_db)
def get_model_class(self):
if self.database is None:
raise RuntimeError('Database must be initialized.')
class BaseModel(Model):
class Meta:
database = self.database
return BaseModel
@property
def Model(self):
if self._app is None:
database = getattr(self, 'database', None)
if database is None:
self.database = Proxy()
if not hasattr(self, '_model_class'):
self._model_class = self.get_model_class()
return self._model_class
def connect_db(self):
self.database.connect()
def close_db(self, exc):
if not self.database.is_closed():
self.database.close()
class Peewee(object):
def __init__(self, app=None):
"""
Initialize the plugin.
"""
self.app = app
self.database = Proxy()
if app is not None:
self.init_app(app)
def init_app(self, app, database=None):
"""
Initialize an application.
"""
if not app:
raise RuntimeError('Invalid application.')
self.app = app
if not hasattr(app, 'extensions'):
app.extensions = {}
app.extensions['peewee'] = self
app.config.setdefault('PEEWEE_CONNECTION_PARAMS', {})
app.config.setdefault('PEEWEE_DATABASE_URI', 'sqlite:///peewee.sqlite')
app.config.setdefault('PEEWEE_MANUAL', False)
app.config.setdefault('PEEWEE_MIGRATE_DIR', 'migrations')
app.config.setdefault('PEEWEE_MIGRATE_TABLE', 'migratehistory')
app.config.setdefault('PEEWEE_MODELS_CLASS', Model)
app.config.setdefault('PEEWEE_MODELS_IGNORE', [])
app.config.setdefault('PEEWEE_MODELS_MODULE', '')
app.config.setdefault('PEEWEE_READ_SLAVES', '')
app.config.setdefault('PEEWEE_USE_READ_SLAVES', True)
# Initialize database
params = app.config['PEEWEE_CONNECTION_PARAMS']
database = database or app.config.get('PEEWEE_DATABASE_URI')
if not database:
raise RuntimeError('Invalid database.')
database = get_database(database, **params)
# Configure read slaves
slaves = app.config['PEEWEE_READ_SLAVES']
if isinstance(slaves, str):
slaves = slaves.split(',')
self.slaves = [
get_database(slave, **params) for slave in slaves if slave
]
self.database.initialize(database)
if self.database.database == ':memory:':
app.config['PEEWEE_MANUAL'] = True
# TODO: Replace this code, when a solution will be found
#if not app.config['PEEWEE_MANUAL']:
# app.before_request(self.connect)
# app.teardown_request(self.close)
def connect(self):
"""
Initialize connection to database.
"""
LOGGER.info('Connecting [%s]', os.getpid())
return self.database.connect()
def close(self, response):
"""
Close connection to database.
"""
LOGGER.info('Closing [%s]', os.getpid())
if not self.database.is_closed():
self.database.close()
return response
@cached_property
def Model(self):
"""
Bind model to self database.
"""
Model_ = self.app.config['PEEWEE_MODELS_CLASS']
meta_params = {'database': self.database}
if self.slaves and self.app.config['PEEWEE_USE_READ_SLAVES']:
meta_params['read_slaves'] = self.slaves
Meta = type('Meta', (), meta_params)
return type('Model', (Model_, ), {'Meta': Meta})
@property
def models(self):
"""
Return self.application models.py.
"""
Model_ = self.app.config['PEEWEE_MODELS_CLASS']
ignore = self.app.config['PEEWEE_MODELS_IGNORE']
models = []
if Model_ is not Model:
try:
mod = import_module(self.app.config['PEEWEE_MODELS_MODULE'])
for model in dir(mod):
models = getattr(mod, model)
if not isinstance(model, PeeweeModel):
continue
models.append(models)
except ImportError:
return models
elif isinstance(Model_, BaseSignalModel):
models = BaseSignalModel.models
return [m for m in models if m._meta.name not in ignore]
def cmd_create(self, name, auto=False):
"""
Create a new migration.
"""
LOGGER.setLevel('INFO')
LOGGER.propagate = 0
router = Router(self.database,
migrate_dir=self.app.config['PEEWEE_MIGRATE_DIR'],
migrate_table=self.app.config['PEEWEE_MIGRATE_TABLE'])
if auto:
auto = self.models
router.create(name, auto=auto)
def cmd_migrate(self, name=None, fake=False):
"""
Run migrations.
"""
LOGGER.setLevel('INFO')
LOGGER.propagate = 0
router = Router(self.database,
migrate_dir=self.app.config['PEEWEE_MIGRATE_DIR'],
migrate_table=self.app.config['PEEWEE_MIGRATE_TABLE'])
migrations = router.run(name, fake=fake)
if migrations:
LOGGER.warn('Migrations are completed: %s' % ', '.join(migrations))
def cmd_rollback(self, name):
"""
Rollback migrations.
"""
LOGGER.setLevel('INFO')
LOGGER.propagate = 0
router = Router(self.database,
migrate_dir=self.app.config['PEEWEE_MIGRATE_DIR'],
migrate_table=self.app.config['PEEWEE_MIGRATE_TABLE'])
router.rollback(name)
def cmd_list(self):
"""
List migrations.
"""
LOGGER.setLevel('DEBUG')
LOGGER.propagate = 0
router = Router(self.database,
migrate_dir=self.app.config['PEEWEE_MIGRATE_DIR'],
migrate_table=self.app.config['PEEWEE_MIGRATE_TABLE'])
LOGGER.info('Migrations are done:')
LOGGER.info('\n'.join(router.done))
LOGGER.info('')
LOGGER.info('Migrations are undone:')
LOGGER.info('\n'.join(router.diff))
def cmd_merge(self):
"""
Merge migrations.
"""
LOGGER.setLevel('DEBUG')
LOGGER.propagate = 0
router = Router(self.database,
migrate_dir=self.app.config['PEEWEE_MIGRATE_DIR'],
migrate_table=self.app.config['PEEWEE_MIGRATE_TABLE'])
router.merge()
@cached_property
def manager(self):
"""
Integration with the Sanic-Script package.
"""
from sanic_script import Manager, Command
manager = Manager(usage="Migrate database.")
manager.add_command('create', Command(self.cmd_create))
manager.add_command('migrate', Command(self.cmd_migrate))
manager.add_command('rollback', Command(self.cmd_rollback))
manager.add_command('list', Command(self.cmd_list))
manager.add_command('merge', Command(self.cmd_merge))
return manager
@cached_property
def cli(self):
import click
@click.group()
def cli():
pass
@cli.command()
@click.argument('name')
@click.option('--auto', is_flag=True)
def create(name, auto=False):
"""
Create a new migration.
"""
return self.cmd_create(name, auto)
@cli.command()
@click.argument('name', default=None, required=False)
@click.option('--fake', is_flag=True)
def migrate(name, fake=False):
"""
Run migrations.
"""
return self.cmd_migrate(name, fake)
@cli.command()
@click.argument('name')
def rollback(name):
"""
Rollback migrations.
"""
return self.cmd_rollback(name)
@cli.command()
def list():
"""
List migrations.
"""
return self.cmd_list()
return cli
