mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-22 17:47:02 +03:00
67 lines
1.9 KiB
Python
67 lines
1.9 KiB
Python
"""Concept example of `Dependency Injector`."""
|
|
|
|
import sqlite3
|
|
|
|
from dependency_injector import catalogs
|
|
from dependency_injector import providers
|
|
from dependency_injector import injections
|
|
|
|
|
|
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(catalogs.DeclarativeCatalog):
|
|
"""Catalog of service providers."""
|
|
|
|
database = providers.Singleton(sqlite3.connect, ':memory:')
|
|
""":type: providers.Provider -> sqlite3.Connection"""
|
|
|
|
users = providers.Factory(UsersService,
|
|
db=database)
|
|
""":type: providers.Provider -> UsersService"""
|
|
|
|
auth = providers.Factory(AuthService,
|
|
db=database,
|
|
users_service=users)
|
|
""":type: providers.Provider -> AuthService"""
|
|
|
|
|
|
# Retrieving catalog providers:
|
|
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()
|
|
|
|
|
|
# Making some "inline" injections:
|
|
@injections.inject(users_service=Services.users)
|
|
@injections.inject(auth_service=Services.auth)
|
|
@injections.inject(database=Services.database)
|
|
def example(users_service, auth_service, database):
|
|
"""Example callback."""
|
|
assert users_service.db is auth_service.db
|
|
assert auth_service.db is database
|
|
assert database is Services.database()
|
|
|
|
|
|
# Making a call of decorated callback:
|
|
example()
|