Wiring container injection (#353)

* Add container injections to wiring

* Add example

* Update docs

* Update changelog

* Improve typing

docs/main/changelog.rst

@@ -7,6 +7,10 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Development version
+-------------------
+- Add container injection support for wiring.
+
 4.6.1
 -----
 - Add Disqus comments widget to the provider's async injections docs page.

docs/wiring.rst

@@ -77,6 +77,13 @@ You can use configuration, provided instance and sub-container providers as you
 You can compound wiring and ``Resource`` provider to implement per-function execution scope.
 See :ref:`Resources, wiring and per-function execution scope <resource-provider-wiring-closing>` for details.
 
+Also you can use ``Provide`` marker to inject a container.
+
+.. literalinclude:: ../examples/wiring/example_container.py
+   :language: python
+   :emphasize-lines: 16-19
+   :lines: 3-
+
 Wiring with modules and packages
 --------------------------------
 

examples/wiring/example_container.py

@@ -0,0 +1,28 @@
+"""Wiring container injection example."""
+
+import sys
+
+from dependency_injector import containers, providers
+from dependency_injector.wiring import inject, Provide
+
+
+class Service:
+    ...
+
+
+class Container(containers.DeclarativeContainer):
+
+    service = providers.Factory(Service)
+
+
+@inject
+def main(container: Container = Provide[Container]):
+    service = container.service()
+    ...
+
+
+if __name__ == '__main__':
+    container = Container()
+    container.wire(modules=[sys.modules[__name__]])
+
+    main()

src/dependency_injector/containers.pyi

@@ -25,6 +25,7 @@ class Container:
     provider_type: Type[Provider] = Provider
     providers: Dict[str, Provider]
     overridden: Tuple[Provider]
+    __self__: Provider
     def __init__(self) -> None: ...
     def __deepcopy__(self, memo: Optional[Dict[str, Any]]) -> Provider: ...
     def __setattr__(self, name: str, value: Union[Provider, Any]) -> None: ...

src/dependency_injector/containers.pyx

@@ -13,6 +13,7 @@ import six
 from .errors import Error
 from .providers cimport (
     Provider,
+    Object,
     Resource,
     deepcopy,
 )
@@ -70,6 +71,7 @@ class DynamicContainer(object):
         self.declarative_parent = None
         self.wired_to_modules = []
         self.wired_to_packages = []
+        self.__self__ = Object(self)
         super(DynamicContainer, self).__init__()
 
     def __deepcopy__(self, memo):
@@ -102,7 +104,7 @@ class DynamicContainer(object):
 
         :rtype: None
         """
-        if isinstance(value, Provider):
+        if isinstance(value, Provider) and name != '__self__':
             _check_provider_type(self, value)
             self.providers[name] = value
         super(DynamicContainer, self).__setattr__(name, value)
@@ -282,6 +284,8 @@ class DeclarativeContainerMetaClass(type):
 
         cls = <type>type.__new__(mcs, class_name, bases, attributes)
 
+        cls.__self__ = Object(cls)
+
         for provider in six.itervalues(cls.providers):
             _check_provider_type(cls, provider)
 
@@ -301,7 +305,7 @@ class DeclarativeContainerMetaClass(type):
 
         :rtype: None
         """
-        if isinstance(value, Provider):
+        if isinstance(value, Provider) and name != '__self__':
             _check_provider_type(cls, value)
             cls.providers[name] = value
             cls.cls_providers[name] = value
@@ -381,6 +385,12 @@ class DeclarativeContainer(object):
     :type: tuple[:py:class:`DeclarativeContainer`]
     """
 
+    __self__ = None
+    """Provider that provides current container.
+
+    :type: :py:class:`dependency_injector.providers.Provider`
+    """
+
     def __new__(cls, **overriding_providers):
         """Constructor.
 

src/dependency_injector/wiring.py

@@ -18,6 +18,7 @@ from typing import (
     Generic,
     TypeVar,
     Type,
+    Union,
     cast,
 )
 
@@ -75,8 +76,8 @@ class ProvidersMap:
     def __init__(self, container):
         self._container = container
         self._map = self._create_providers_map(
-            current_providers=container.providers,
-            original_providers=container.declarative_parent.providers,
+            current_container=container,
+            original_container=container.declarative_parent,
         )
 
     def resolve_provider(
@@ -173,9 +174,15 @@ class ProvidersMap:
     @classmethod
     def _create_providers_map(
             cls,
-            current_providers: Dict[str, providers.Provider],
-            original_providers: Dict[str, providers.Provider],
+            current_container: Container,
+            original_container: Container,
     ) -> Dict[providers.Provider, providers.Provider]:
+        current_providers = current_container.providers
+        current_providers['__self__'] = current_container.__self__
+
+        original_providers = original_container.providers
+        original_providers['__self__'] = original_container.__self__
+
         providers_map = {}
         for provider_name, current_provider in current_providers.items():
             original_provider = original_providers[provider_name]
@@ -184,8 +191,8 @@ class ProvidersMap:
             if isinstance(current_provider, providers.Container) \
                     and isinstance(original_provider, providers.Container):
                 subcontainer_map = cls._create_providers_map(
-                    current_providers=current_provider.container.providers,
-                    original_providers=original_provider.container.providers,
+                    current_container=current_provider.container,
+                    original_container=original_provider.container,
                 )
                 providers_map.update(subcontainer_map)
 
@@ -479,6 +486,12 @@ def _is_declarative_container_instance(instance: Any) -> bool:
             and getattr(instance, 'declarative_parent', None) is not None)
 
 
+def _is_declarative_container(instance: Any) -> bool:
+    return (isinstance(instance, type)
+            and getattr(instance, '__IS_CONTAINER__', False) is True
+            and getattr(instance, 'declarative_parent', None) is None)
+
+
 class ClassGetItemMeta(GenericMeta):
     def __getitem__(cls, item):
         # Spike for Python 3.6
@@ -487,8 +500,10 @@ class ClassGetItemMeta(GenericMeta):
 
 class _Marker(Generic[T], metaclass=ClassGetItemMeta):
 
-    def __init__(self, provider: providers.Provider) -> None:
-        self.provider = provider
+    def __init__(self, provider: Union[providers.Provider, Container]) -> None:
+        if _is_declarative_container(provider):
+            provider = provider.__self__
+        self.provider: providers.Provider = provider
 
     def __class_getitem__(cls, item) -> T:
         return cls(item)

tests/unit/samples/wiringsamples/module.py

@@ -91,3 +91,7 @@ class ClassDecorator:
 @inject
 def test_class_decorator(service: Service = Provide[Container.service]):
     return service
+
+
+def test_container(container: Container = Provide[Container]):
+    return container.service()

tests/unit/wiring/test_wiring_py36.py

@@ -239,6 +239,10 @@ class WiringTest(unittest.TestCase):
         service = module.test_class_decorator()
         self.assertIsInstance(service, Service)
 
+    def test_container(self):
+        service = module.test_container()
+        self.assertIsInstance(service, Service)
+
 
 class WiringAndFastAPITest(unittest.TestCase):