Add docs and example for Factory.add_attributes() method

Author: rmk135

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 docs and example for ``Factory.add_attributes()`` method.
+
 4.29.0
 ------
 - Implement context manager interface for resetting a singleton provider.

docs/providers/factory.rst

@@ -40,6 +40,14 @@ injected following these rules:
    :language: python
    :lines: 3-
 
+``Factory`` provider can inject attributes. Use ``.add_attributes()`` method to specify
+attribute injections.
+
+.. literalinclude:: ../../examples/providers/factory_attribute_injections.py
+   :language: python
+   :lines: 3-
+   :emphasize-lines: 18-18
+
 Passing arguments to the underlying providers
 ---------------------------------------------
 

examples/providers/factory_attribute_injections.py

@@ -0,0 +1,28 @@
+"""`Factory` provider attribute injections example."""
+
+from dependency_injector import containers, providers
+
+
+class Client:
+    ...
+
+
+class Service:
+    def __init__(self) -> None:
+        self.client = None
+
+
+class Container(containers.DeclarativeContainer):
+
+    client = providers.Factory(Client)
+
+    service = providers.Factory(Service)
+    service.add_attributes(clent=client)
+
+
+if __name__ == '__main__':
+    container = Container()
+
+    service = container.service()
+
+    assert isinstance(service.client, Client)