Add container usage for all singleton provider examples

docs/providers/singleton.rst

@@ -41,7 +41,7 @@ provider.
 .. literalinclude:: ../../examples/providers/singleton_resetting.py
    :language: python
    :lines: 3-
-   :emphasize-lines: 14
+   :emphasize-lines: 18
 
 .. note::
    Resetting of the memorized object clears the reference to it. Further object's lifecycle is
@@ -64,7 +64,7 @@ There are two thread-safe singleton implementations out of the box:
 .. literalinclude:: ../../examples/providers/singleton_thread_locals.py
    :language: python
    :lines: 3-
-   :emphasize-lines: 11,12
+   :emphasize-lines: 13,15
 
 Implementing scopes
 -------------------

examples/providers/singleton.py

@@ -1,16 +1,20 @@
 """`Singleton` provider example."""
 
-from dependency_injector import providers
+from dependency_injector import containers, providers
 
 
 class UserService:
     ...
 
 
-user_service_provider = providers.Singleton(UserService)
+class Container(containers.DeclarativeContainer):
+
+    user_service_provider = providers.Singleton(UserService)
 
 
 if __name__ == '__main__':
-    user_service1 = user_service_provider()
-    user_service2 = user_service_provider()
+    container = Container()
+
+    user_service1 = container.user_service_provider()
+    user_service2 = container.user_service_provider()
     assert user_service1 is user_service2

examples/providers/singleton_resetting.py

@@ -1,19 +1,23 @@
 """`Singleton` provider resetting example."""
 
-from dependency_injector import providers
+from dependency_injector import containers, providers
 
 
 class UserService:
     ...
 
 
-user_service_provider = providers.Singleton(UserService)
+class Container(containers.DeclarativeContainer):
+
+    user_service_provider = providers.Singleton(UserService)
 
 
 if __name__ == '__main__':
-    user_service1 = user_service_provider()
+    container = Container()
 
-    user_service_provider.reset()
+    user_service1 = container.user_service_provider()
 
-    users_service2 = user_service_provider()
+    container.user_service_provider.reset()
+
+    users_service2 = container.user_service_provider()
     assert users_service2 is not user_service1

examples/providers/singleton_scoped.py

@@ -1,30 +1,35 @@
 """`Singleton` - Flask request scope example."""
 
-from dependency_injector import providers
-from flask import Flask
+from dependency_injector import containers, providers
+from flask import Flask, current_app
 
 
 class Service:
     ...
 
 
-service_provider = providers.Singleton(Service)
+class Container(containers.DeclarativeContainer):
+
+    service_provider = providers.Singleton(Service)
 
 
 def index_view():
-    service_1 = service_provider()
-    service_2 = service_provider()
+    service_1 = current_app.container.service_provider()
+    service_2 = current_app.container.service_provider()
     assert service_1 is service_2
     print(service_1)
     return 'Hello  World!'
 
 
 def teardown_context(request):
-    service_provider.reset()
+    current_app.container.service_provider.reset()
     return request
 
 
+container = Container()
+
 app = Flask(__name__)
+app.container = container
 app.add_url_rule('/', 'index', view_func=index_view)
 app.after_request(teardown_context)
 

examples/providers/singleton_thread_locals.py

@@ -3,31 +3,39 @@
 import threading
 import queue
 
-from dependency_injector import providers
+from dependency_injector import containers, providers
 
 
 def put_in_queue(example_object, queue_object):
     queue_object.put(example_object)
 
 
-thread_local_object = providers.ThreadLocalSingleton(object)
-queue_provider = providers.ThreadSafeSingleton(queue.Queue)
-put_in_queue = providers.Callable(
-    put_in_queue,
-    example_object=thread_local_object,
-    queue_object=queue_provider,
-)
-thread_factory = providers.Factory(
-    threading.Thread,
-    target=put_in_queue.provider,
-)
+class Container(containers.DeclarativeContainer):
+
+    thread_local_object = providers.ThreadLocalSingleton(object)
+
+    queue_provider = providers.ThreadSafeSingleton(queue.Queue)
+
+    put_in_queue = providers.Callable(
+        put_in_queue,
+        example_object=thread_local_object,
+        queue_object=queue_provider,
+    )
+
+    thread_factory = providers.Factory(
+        threading.Thread,
+        target=put_in_queue.provider,
+    )
 
 
 if __name__ == '__main__':
+    container = Container()
+
+    n = 10
     threads = []
-    for thread_number in range(10):
+    for thread_number in range(n):
         threads.append(
-            thread_factory(name='Thread{0}'.format(thread_number)),
+            container.thread_factory(name='Thread{0}'.format(thread_number)),
         )
     for thread in threads:
         thread.start()
@@ -35,9 +43,9 @@ if __name__ == '__main__':
         thread.join()
 
     all_objects = set()
-    while not queue_provider().empty():
-        all_objects.add(queue_provider().get())
+    while not container.queue_provider().empty():
+        all_objects.add(container.queue_provider().get())
 
-    assert len(all_objects) == len(threads)
+    assert len(all_objects) == len(threads) == n
     # Queue contains same number of objects as number of threads where
     # thread-local singleton provider was used.