mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-22 17:47:02 +03:00
46 lines
1.3 KiB
Python
46 lines
1.3 KiB
Python
"""`NewInstance` and `Singleton` providers with injections example."""
|
|
|
|
import sqlite3
|
|
|
|
from objects.providers import Singleton
|
|
from objects.providers import NewInstance
|
|
|
|
from objects.injections import KwArg
|
|
from objects.injections import Attribute
|
|
|
|
|
|
class ObjectA(object):
|
|
|
|
"""ObjectA has dependency on database."""
|
|
|
|
def __init__(self, database):
|
|
"""Initializer.
|
|
|
|
Database dependency need to be injected via init arg."""
|
|
self.database = database
|
|
|
|
def get_one(self):
|
|
"""Select one from database and return it."""
|
|
return self.database.execute('SELECT 1').fetchone()[0]
|
|
|
|
|
|
# Database and `ObjectA` providers.
|
|
database = Singleton(sqlite3.Connection,
|
|
KwArg('database', ':memory:'),
|
|
KwArg('timeout', 30),
|
|
KwArg('detect_types', True),
|
|
KwArg('isolation_level', 'EXCLUSIVE'),
|
|
Attribute('row_factory', sqlite3.Row))
|
|
|
|
object_a = NewInstance(ObjectA,
|
|
KwArg('database', database))
|
|
|
|
# Creating several `ObjectA` instances.
|
|
object_a_1 = object_a()
|
|
object_a_2 = object_a()
|
|
|
|
# Making some asserts.
|
|
assert object_a_1 is not object_a_2
|
|
assert object_a_1.database is object_a_2.database is database()
|
|
assert object_a_1.get_one() == object_a_2.get_one() == 1
|