python-dependency-injector/examples/providers/overriding_users_model.py

94 lines
2.6 KiB
Python

"""Overriding user's model example."""
from dependency_injector import providers
class User(object):
"""Example class User."""
def __init__(self, id, password):
"""Initializer."""
self.id = id
self.password = password
super(User, self).__init__()
class UserService(object):
"""Example class UserService."""
def __init__(self, user_cls):
"""Initializer."""
self.user_cls = user_cls
super(UserService, self).__init__()
def get_by_id(self, id):
"""Find user by his id and return user model."""
return self.user_cls(id=id, password='secret' + str(id))
# Users factory and UserService provider:
users_service = providers.Factory(UserService, user_cls=User)
# Getting several users and making some asserts:
user1 = users_service().get_by_id(1)
user2 = users_service().get_by_id(2)
assert isinstance(user1, User)
assert user1.id == 1
assert user1.password == 'secret1'
assert isinstance(user2, User)
assert user2.id == 2
assert user2.password == 'secret2'
assert user1 is not user2
# Extending user model and user service for adding custom attributes without
# making any changes to client's code.
class ExtendedUser(User):
"""Example class ExtendedUser."""
def __init__(self, id, password, first_name=None, last_name=None,
gender=None):
"""Initializer."""
self.first_name = first_name
self.last_name = last_name
self.gender = gender
super(ExtendedUser, self).__init__(id, password)
class ExtendedUserService(UserService):
"""Example class ExtendedUserService."""
def get_by_id(self, id):
"""Find user by his id and return user model."""
user = super(ExtendedUserService, self).get_by_id(id)
user.first_name = 'John' + str(id)
user.last_name = 'Smith' + str(id)
user.gender = 'male'
return user
# Overriding users_service provider:
extended_users_service = providers.Factory(ExtendedUserService,
user_cls=ExtendedUser)
users_service.override(extended_users_service)
# Getting few other users users and making some asserts:
user3 = users_service().get_by_id(3)
user4 = users_service().get_by_id(4)
assert isinstance(user3, ExtendedUser)
assert user3.id == 3
assert user3.password == 'secret3'
assert user3.first_name == 'John3'
assert user3.last_name == 'Smith3'
assert isinstance(user4, ExtendedUser)
assert user4.id == 4
assert user4.password == 'secret4'
assert user4.first_name == 'John4'
assert user4.last_name == 'Smith4'
assert user3 is not user4