mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-25 19:14:00 +03:00
57 lines
1.2 KiB
Python
57 lines
1.2 KiB
Python
"""
|
|
Example of providers delegate.
|
|
"""
|
|
|
|
from objects import AbstractCatalog
|
|
from objects.providers import (
|
|
Singleton,
|
|
NewInstance,
|
|
)
|
|
from objects.injections import (
|
|
InitArg,
|
|
Attribute,
|
|
)
|
|
|
|
|
|
import sqlite3
|
|
|
|
|
|
# Some example classes.
|
|
class ObjectA(object):
|
|
def __init__(self, db):
|
|
self.db = db
|
|
|
|
|
|
class ObjectB(object):
|
|
def __init__(self, a_factory):
|
|
self.a_factory = a_factory
|
|
|
|
|
|
# Catalog of objects providers.
|
|
class Catalog(AbstractCatalog):
|
|
"""
|
|
Objects catalog.
|
|
"""
|
|
|
|
database = Singleton(sqlite3.Connection,
|
|
InitArg('database', ':memory:'),
|
|
Attribute('row_factory', sqlite3.Row))
|
|
""" :type: (objects.Provider) -> sqlite3.Connection """
|
|
|
|
object_a = NewInstance(ObjectA,
|
|
InitArg('db', database))
|
|
""" :type: (objects.Provider) -> ObjectA """
|
|
|
|
object_b = Singleton(ObjectB,
|
|
InitArg('a_factory', object_a.delegate()))
|
|
""" :type: (objects.Provider) -> ObjectB """
|
|
|
|
|
|
# Catalog static provides.
|
|
b = Catalog.object_b()
|
|
a1, a2 = b.a_factory(), b.a_factory()
|
|
|
|
# Some asserts.
|
|
assert a1 is not a2
|
|
assert a1.db is a2.db is Catalog.database()
|