python-dependency-injector/docs/providers/callable.rst
2015-07-16 02:39:21 +03:00

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Callable providers
------------------
``Callable`` provider is a provider that wraps particular callable with
some injections. Every call of this provider returns result of call of initial
callable.
``Callable`` provider uses ``KwArg`` injections. ``KwArg`` injections are
done by passing injectable values as keyword arguments during call time.
Context keyword arguments have higher priority than ``KwArg`` injections.
Example:
.. image:: /images/callable.png
:width: 100%
:align: center
.. code-block:: python
"""`Callable` providers example."""
from passlib.hash import sha256_crypt
from objects.providers import Callable
from objects.injections import KwArg
# Password hasher and verifier providers (hash function could be changed
# anytime (for example, to sha512) without any changes in client's code):
password_hasher = Callable(sha256_crypt.encrypt,
KwArg('salt_size', 16),
KwArg('rounds', 10000))
password_verifier = Callable(sha256_crypt.verify)
# Making some asserts (client's code):
hashed_password = password_hasher('super secret')
assert password_verifier('super secret', hashed_password)