python-dependency-injector/examples/containers/declarative_injections.py
2016-06-03 19:20:34 +03:00

48 lines
1.3 KiB
Python

"""Declarative IoC container's provider injections example."""
import sqlite3
import dependency_injector.containers as containers
import dependency_injector.providers as providers
class UsersService(object):
"""Users service, that has dependency on database."""
def __init__(self, db):
"""Initializer."""
self.db = db
class AuthService(object):
"""Auth service, that has dependencies on users service and database."""
def __init__(self, db, users_service):
"""Initializer."""
self.db = db
self.users_service = users_service
class Services(containers.DeclarativeContainer):
"""IoC container of service providers."""
database = providers.Singleton(sqlite3.connect, ':memory:')
users = providers.Factory(UsersService,
db=database)
auth = providers.Factory(AuthService,
db=database,
users_service=users)
# Retrieving service providers from container:
users_service = Services.users()
auth_service = Services.auth()
# Making some asserts:
assert users_service.db is auth_service.db is Services.database()
assert isinstance(auth_service.users_service, UsersService)
assert users_service is not Services.users()
assert auth_service is not Services.auth()