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46 lines
1.3 KiB
Python
46 lines
1.3 KiB
Python
"""`Factory` and `Singleton` providers with injections example."""
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import sqlite3
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from objects.providers import Singleton
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from objects.providers import Factory
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from objects.injections import KwArg
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from objects.injections import Attribute
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class ObjectA(object):
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"""ObjectA has dependency on database."""
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def __init__(self, database):
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"""Initializer.
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Database dependency need to be injected via init arg."""
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self.database = database
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def get_one(self):
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"""Select one from database and return it."""
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return self.database.execute('SELECT 1').fetchone()[0]
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# Database and `ObjectA` providers.
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database = Singleton(sqlite3.Connection,
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KwArg('database', ':memory:'),
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KwArg('timeout', 30),
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KwArg('detect_types', True),
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KwArg('isolation_level', 'EXCLUSIVE'),
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Attribute('row_factory', sqlite3.Row))
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object_a_factory = Factory(ObjectA,
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KwArg('database', database))
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# Creating several `ObjectA` instances.
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object_a_1 = object_a_factory()
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object_a_2 = object_a_factory()
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# Making some asserts.
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assert object_a_1 is not object_a_2
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assert object_a_1.database is object_a_2.database is database()
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assert object_a_1.get_one() == object_a_2.get_one() == 1
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