Add flask example to the docs

docs/examples/flask.rst

@@ -0,0 +1,85 @@
+Flask example
+=============
+
+.. meta::
+   :keywords: Python,Dependency Injection,Flask,Example
+   :description: This example demonstrates a usage of the Flask and Dependency Injector.
+
+
+This example shows how to use ``Dependency Injector`` with `Flask <https://flask.palletsprojects.com/en/1.1.x/>`_.
+
+The example application helps to search for repositories on the Github.
+
+.. image:: images/flask.png
+    :width: 100%
+    :align: center
+
+The source code is available on the `Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/flask>`_.
+
+:ref:`flask-tutorial` demonstrates how to build this application step-by-step.
+
+Application structure
+---------------------
+
+Application has next structure:
+
+.. code-block:: bash
+
+   ./
+   ├── githubnavigator/
+   │   ├── templates
+   │   │   ├── base.html
+   │   │   └── index.py
+   │   ├── __init__.py
+   │   ├── application.py
+   │   ├── containers.py
+   │   ├── services.py
+   │   ├── tests.py
+   │   └── views.py
+   ├── config.yml
+   └── requirements.txt
+
+Container
+---------
+
+Declarative container is defined in ``githubnavigator/containers.py``:
+
+.. literalinclude:: ../../examples/miniapps/flask/githubnavigator/containers.py
+   :language: python
+
+Views
+-----
+
+View has dependencies on search service and some config options. The dependencies are injected
+using :ref:`wiring` feature.
+
+Listing of ``githubnavigator/views.py``:
+
+.. literalinclude:: ../../examples/miniapps/flask/githubnavigator/views.py
+   :language: python
+
+Application factory
+-------------------
+Application factory creates container, wires it with the ``views`` module, creates
+``Flask`` app and setup routes.
+
+Listing of ``githubnavigator/application.py``:
+
+.. literalinclude:: ../../examples/miniapps/flask/githubnavigator/application.py
+   :language: python
+
+Tests
+-----
+
+Tests use :ref:`provider-overriding` feature to replace search service with a mock ``githubnavigator/tests.py``:
+
+.. literalinclude:: ../../examples/miniapps/flask/githubnavigator/tests.py
+   :language: python
+   :emphasize-lines: 44,67
+
+Sources
+-------
+
+Explore the sources on the `Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/flask>`_.
+
+.. disqus::

docs/examples/index.rst

@@ -14,6 +14,7 @@ Explore the examples to see the ``Dependency Injector`` in action.
     application-multiple-containers
     decoupled-packages
     django
+    flask
     sanic
 
 .. disqus::

docs/examples/sanic.rst

@@ -54,7 +54,7 @@ Listing of ``giphynavigator/handlers.py``:
 Application factory
 -------------------
 Application factory creates container, wires it with the ``handlers`` module, creates
-``Sanic`` app instance and setup routes.
+``Sanic`` app and setup routes.
 
 Listing of ``giphynavigator/application.py``:
 
@@ -64,7 +64,7 @@ Listing of ``giphynavigator/application.py``:
 Tests
 -----
 
-Tests use :ref:`provider-overriding` feature to replace search service with a mock ``web/giphynavigator.py``:
+Tests use :ref:`provider-overriding` feature to replace search service with a mock ``giphynavigator/tests.py``:
 
 .. literalinclude:: ../../examples/miniapps/sanic/giphynavigator/tests.py
    :language: python