mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-22 09:36:48 +03:00
103 lines
2.5 KiB
Python
103 lines
2.5 KiB
Python
"""
|
|
Concept example of objects catalogs.
|
|
"""
|
|
|
|
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, db):
|
|
self.a = a
|
|
self.db = db
|
|
|
|
|
|
# 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 = NewInstance(ObjectB,
|
|
InitArg('a', object_a),
|
|
InitArg('db', database))
|
|
""" :type: (objects.Provider) -> ObjectB """
|
|
|
|
|
|
# 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()
|
|
|
|
|
|
# Dependencies injection (The Python Way) into class.
|
|
class Consumer(object):
|
|
|
|
dependencies = Catalog(Catalog.object_a,
|
|
Catalog.object_b)
|
|
|
|
def test(self):
|
|
a1 = self.dependencies.object_a()
|
|
a2 = self.dependencies.object_a()
|
|
|
|
b1 = self.dependencies.object_b()
|
|
b2 = self.dependencies.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
|
|
|
|
try:
|
|
self.dependencies.database()
|
|
except AttributeError:
|
|
pass
|
|
else:
|
|
raise Exception('Database is not listed as a dependency')
|
|
|
|
Consumer().test()
|
|
|
|
|
|
# Dependencies injection (The Python Way) into a callback.
|
|
def consumer_callback(dependencies=Catalog(Catalog.object_a,
|
|
Catalog.object_b)):
|
|
a1 = dependencies.object_a()
|
|
a2 = dependencies.object_a()
|
|
|
|
b1 = dependencies.object_b()
|
|
b2 = dependencies.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
|
|
|
|
try:
|
|
dependencies.database()
|
|
except AttributeError:
|
|
pass
|
|
else:
|
|
raise Exception('Database is not listed as a dependency')
|