"""Dependency injector injections module.""" import six from dependency_injector.providers.base import ( _parse_positional_injections, _parse_keyword_injections, ) from dependency_injector import utils from dependency_injector import errors def inject(*args, **kwargs): """Dependency injection decorator. :py:func:`inject` decorator can be used for making inline dependency injections. It patches decorated callable in such way that dependency injection will be done during every call of decorated callable. :py:func:`inject` decorator supports different syntaxes of passing injections: .. code-block:: python # Positional arguments injections: @inject(1, 2) def some_function(arg1, arg2): pass # Keyword arguments injections: @inject(arg1=1) @inject(arg2=2) def some_function(arg1, arg2): pass # Keyword arguments injections into class init: @inject(arg1=1) @inject(arg2=2) class SomeClass(object): def __init__(self, arg1, arg2): pass :param args: Tuple of context positional arguments. :type args: tuple[object] :param kwargs: Dictionary of context keyword arguments. :type kwargs: dict[str, object] :return: Class / callable decorator :rtype: (callable) -> (type | callable) """ arg_injections = _parse_positional_injections(args) kwarg_injections = _parse_keyword_injections(kwargs) def decorator(callback_or_cls): """Dependency injection decorator.""" if isinstance(callback_or_cls, six.class_types): cls = callback_or_cls cls_init = utils.fetch_cls_init(cls) if not cls_init: raise errors.Error( 'Class {0}.{1} has no __init__() '.format(cls.__module__, cls.__name__) + 'method and could not be decorated with @inject decorator') cls.__init__ = decorator(cls_init) return cls callback = callback_or_cls if hasattr(callback, '__INJECT_DECORATED__'): callback.args += arg_injections callback.kwargs.update(kwarg_injections) return callback @six.wraps(callback) def decorated(*args, **kwargs): """Decorated with dependency injection callback.""" if decorated.args: args = tuple(arg.provide_injection() for arg in decorated.args) + args for name, arg in six.iteritems(decorated.kwargs): if name not in kwargs: kwargs[name] = arg.provide_injection() return callback(*args, **kwargs) decorated.__INJECT_DECORATED__ = True decorated.origin = callback decorated.args = arg_injections decorated.kwargs = kwarg_injections return decorated return decorator