python-dependency-injector/examples/overrides.py
Roman Mogilatov 143ba92b0a 0.0.4 version
2015-01-11 18:10:11 +02:00

57 lines
1.3 KiB
Python

"""
Concept example of objects overrides.
"""
from objects import Catalog, Singleton, NewInstance, InitArg, Attribute, overrides
import sqlite3
# Some example class.
class ObjectA(object):
def __init__(self, db):
self.db = db
class ObjectAMock(ObjectA):
pass
# Catalog of objects providers.
class AppCatalog(Catalog):
"""
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 """
# Overriding AppCatalog by SandboxCatalog with some mocks.
@overrides(AppCatalog)
class SandboxCatalog(AppCatalog):
"""
Sandbox objects catalog with some mocks.
"""
object_a = NewInstance(ObjectAMock,
InitArg('db', AppCatalog.database))
""" :type: (objects.Provider) -> ObjectA """
# Catalog static provides.
a1 = AppCatalog.object_a()
a2 = AppCatalog.object_a()
# Some asserts.
assert isinstance(a1, ObjectAMock)
assert isinstance(a2, ObjectAMock)
assert a1 is not a2
assert a1.db is a2.db is AppCatalog.database()