mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-23 01:56:58 +03:00
64 lines
1.6 KiB
Python
64 lines
1.6 KiB
Python
"""External dependency example."""
|
|
|
|
from objects import AbstractCatalog
|
|
|
|
from objects.providers import Singleton
|
|
from objects.providers import NewInstance
|
|
from objects.providers import ExternalDependency
|
|
|
|
from objects.injections import InitArg
|
|
from objects.injections import Attribute
|
|
|
|
import sqlite3
|
|
|
|
|
|
class ObjectA(object):
|
|
|
|
"""Example class ObjectA, that has dependency on database."""
|
|
|
|
def __init__(self, db):
|
|
"""Initializer."""
|
|
self.db = db
|
|
|
|
|
|
class ObjectB(object):
|
|
|
|
"""Example class ObjectB, that has dependencies on ObjectA and database."""
|
|
|
|
def __init__(self, a, db):
|
|
"""Initializer."""
|
|
self.a = a
|
|
self.db = db
|
|
|
|
|
|
class Catalog(AbstractCatalog):
|
|
|
|
"""Catalog of objects providers."""
|
|
|
|
database = ExternalDependency(instance_of=sqlite3.Connection)
|
|
""":type: (objects.Provider) -> sqlite3.Connection"""
|
|
|
|
object_a = NewInstance(ObjectA,
|
|
InitArg('db', database))
|
|
""":type: (objects.Provider) -> ObjectA"""
|
|
|
|
object_b = NewInstance(ObjectB,
|
|
InitArg('a', object_a),
|
|
InitArg('db', database))
|
|
""":type: (objects.Provider) -> ObjectB"""
|
|
|
|
|
|
# Satisfaction of external dependency.
|
|
Catalog.database.override(Singleton(sqlite3.Connection,
|
|
InitArg('database', ':memory:'),
|
|
Attribute('row_factory', sqlite3.Row)))
|
|
|
|
# Catalog static provides.
|
|
a1, a2 = Catalog.object_a(), Catalog.object_a()
|
|
b1, b2 = Catalog.object_b(), Catalog.object_b()
|
|
|
|
# Some asserts.
|
|
assert a1 is not a2
|
|
assert b1 is not b2
|
|
assert a1.db is a2.db is b1.db is b2.db is Catalog.database()
|