python-dependency-injector/dependency_injector/injections.py
2015-09-01 00:30:38 +03:00

80 lines
1.8 KiB
Python

"""Injections module."""
import six
from .utils import is_provider
from .utils import ensure_is_injection
from .utils import get_injectable_kwargs
class Injection(object):
"""Base injection class."""
__IS_INJECTION__ = True
__slots__ = ('name', 'injectable')
def __init__(self, name, injectable):
"""Initializer."""
self.name = name
self.injectable = injectable
@property
def value(self):
"""Return injectable value."""
if is_provider(self.injectable):
return self.injectable()
return self.injectable
class KwArg(Injection):
"""Keyword argument injection."""
__IS_KWARG_INJECTION__ = True
class Attribute(Injection):
"""Attribute injection."""
__IS_ATTRIBUTE_INJECTION__ = True
class Method(Injection):
"""Method injection."""
__IS_METHOD_INJECTION__ = True
def inject(*args, **kwargs):
"""Dependency injection decorator.
:type injection: Injection
:return: (callable) -> (callable)
"""
injections = tuple((KwArg(name, value)
for name, value in six.iteritems(kwargs)))
if args:
injections += tuple((ensure_is_injection(injection)
for injection in args))
def decorator(callback):
"""Dependency injection decorator."""
if hasattr(callback, '_injections'):
callback._injections += injections
return callback
@six.wraps(callback)
def decorated(*args, **kwargs):
"""Decorated with dependency injection callback."""
return callback(*args,
**get_injectable_kwargs(kwargs,
decorated._injections))
decorated._injections = injections
return decorated
return decorator