Minor formatting adjustments. Add file comments for main.py.

Change-Id: Iaf5a7d00f15ed548b9e3e29ce63c84c039156866

Author: AndrewMBurke

flask/01-basic-app/main.py

@@ -1,38 +1,44 @@
+#!/usr/bin/env python3
 # Copyright 2021 Google LLC
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
 #
 #     https://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+"""The Flask server application. Defines routes.
+
+Ensure that you select an approprate run strategy at the bottom of this file.
+"""
 
 import flask
 import os
 
+# Instantiate the Flask application.
 app = flask.Flask(__name__)
 
-# Note: A secret key is included in the sample so that it works.
-# If you use this code in your application, replace this with a truly secret
-# key. See https://flask.palletsprojects.com/quickstart/#sessions.
+# Note: A secret key is included in the sample so that it works. If you use this
+# code in your application, replace this with a truly secret key. See
+# https://flask.palletsprojects.com/quickstart/#sessions.
 app.secret_key = "REPLACE ME - this value is here as a placeholder."
 
 
 @app.route("/")
 def index():
     """
     Render the index page from the "index.html" template. This is meant to act
-    as a facsimile of a company's home page.
-    The Add-on Discovery URL should be set to the /classroom-addon route below.
+    as a facsimile of a company's home page. The Add-on Discovery URL should be
+    set to the /classroom-addon route below.
     """
 
-    return flask.render_template("index.html",
-                                 message="You've reached the index page.")
+    return flask.render_template(
+        "index.html", message="You've reached the index page.")
 
 
 @app.route("/classroom-addon")
@@ -54,23 +60,23 @@ def classroom_addon():
     ### OPTION 1: Unsecured localhost
     # When running locally on unsecured HTTP, use this line to disable
     # OAuthlib's HTTPs verification.
+
     # Important: When running in production *do not* leave this option enabled.
-    # os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
+    os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
 
     # Run the application on a local server, defaults to http://localhost:5000.
     # Note: the OAuth flow requires a TLD, *not* an IP address; "localhost" is
-    #   acceptable, but http://127.0.0.1 is not.
+    # acceptable, but http://127.0.0.1 is not.
     app.run(debug=True)
 
     ### OPTION 2: Secure localhost
     # Run the application over HTTPs with a locally stored certificate and key.
     # Defaults to https://localhost:5000.
     # app.run(host="localhost",
-    #         ssl_context=("localhost.pem", "localhost-key.pem"),
-    #         debug=True)
+    #   ssl_context=("localhost.pem", "localhost-key.pem"), debug=True)
 
     ### OPTION 3: Production- or cloud-ready server
-    # Start a Gunicorn server, which is appropriate for use in
-    # production or a cloud deployment.
+    # Start a Gunicorn server, which is appropriate for use in production or a
+    # cloud deployment.
     # server_port = os.environ.get("PORT", "8080")
     # app.run(debug=True, port=server_port, host="0.0.0.0")

flask/01-basic-app/static/base-style.css

@@ -35,7 +35,7 @@ body {
     text-decoration: none;
     font-size: 17px;
     display: block;
-    }
+}
 
 .topnav a:hover {
     background-color: #ddd;

flask/02-sign-in/main.py

@@ -1,16 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2021 Google LLC
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+"""The Flask server application. Defines routes and ancillary methods.
+
+Ensure that you select an approprate run strategy at the bottom of this file.
+"""
 
 import os
 import flask
@@ -21,11 +26,12 @@
 import google_auth_oauthlib.flow
 import googleapiclient.discovery
 
+# Instantiate the Flask application.
 app = flask.Flask(__name__)
 
-# Note: A secret key is included in the sample so that it works.
-# If you use this code in your application, replace this with a truly secret
-# key. See https://flask.palletsprojects.com/quickstart/#sessions.
+# Note: A secret key is included in the sample so that it works. If you use this
+# code in your application, replace this with a truly secret key. See
+# https://flask.palletsprojects.com/quickstart/#sessions.
 app.secret_key = "REPLACE ME - this value is here as a placeholder."
 
 # Configure the flask cookie settings per the iframe security recommendations:
@@ -42,8 +48,8 @@
 
 # This OAuth 2.0 access scope allows for full read/write access to the
 # authenticated user's account and requires requests to use an SSL connection.
-# These scopes should match the scopes in your GCP project's
-# OAuth Consent Screen: https://console.cloud.google.com/apis/credentials/consent
+# These scopes should match the scopes in your GCP project's OAuth Consent
+# Screen: https://console.cloud.google.com/apis/credentials/consent
 SCOPES = [
     "https://www.googleapis.com/auth/userinfo.profile",
     "https://www.googleapis.com/auth/userinfo.email"
@@ -54,21 +60,21 @@
 def index():
     """
     Render the index page from the "index.html" template. This is meant to act
-    as a facsimile of a company's home page.
-    The Add-on Discovery URL should be set to the /classroom-addon route below.
+    as a facsimile of a company's home page. The Add-on Discovery URL should be
+    set to the /classroom-addon route below.
     """
 
-    return flask.render_template("index.html",
-                                 message="You've reached the index page.")
+    return flask.render_template(
+        "index.html", message="You've reached the index page.")
 
 
 @app.route("/classroom-addon")
 def classroom_addon():
     """
     Checks if a user is signed in. If so, renders the addon discovery page from
     the "addon-discovery.html" template. This is meant to be the landing page
-    when opening the web app in the Classroom add-on iframe.
-    Otherwise, renders the "authorization.html" template.
+    when opening the web app in the Classroom add-on iframe. Otherwise, renders
+    the "authorization.html" template.
     """
 
     if "credentials" not in flask.session:
@@ -82,10 +88,11 @@ def classroom_addon():
 @app.route("/test/<request_type>")
 def test_api_request(request_type="username"):
     """
-    Tests an API request, rendering the result in the "show-api-query-result.html" template.
+    Tests an API request, rendering the result in the
+    "show-api-query-result.html" template.
 
-    Args:
-        request_type: The type of API request to test. Currently only "username" is supported.
+    Args: request_type: The type of API request to test. Currently only
+        "username" is supported.
     """
 
     if "credentials" not in flask.session:
@@ -110,13 +117,14 @@ def test_api_request(request_type="username"):
 
     # Save credentials back to session in case access token was refreshed.
     # ACTION ITEM: In a production app, you likely want to save these
-    #              credentials in a persistent database instead.
+    # credentials in a persistent database instead.
     flask.session["credentials"] = credentials_to_dict(credentials)
 
     # Render the results of the API call.
-    return flask.render_template("show-api-query-result.html",
-                                 data=json.dumps(fetched_data, indent=2),
-                                 data_title=request_type)
+    return flask.render_template(
+        "show-api-query-result.html",
+        data=json.dumps(fetched_data, indent=2),
+        data_title=request_type)
 
 
 @app.route("/authorize")
@@ -125,14 +133,15 @@ def authorize():
     Initializes the OAuth flow and redirects to Google's authorization page.
     """
 
-    # Create flow instance to manage the OAuth 2.0 Authorization Grant Flow steps.
+    # Create flow instance to manage the OAuth 2.0 Authorization Grant Flow
+    # steps.
     flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
         CLIENT_SECRETS_FILE, scopes=SCOPES)
 
-    # The URI created here must exactly match one of the authorized redirect URIs
-    # for the OAuth 2.0 client, which you configured in the API Console. If this
-    # value doesn't match an authorized URI, you will get a "redirect_uri_mismatch"
-    # error.
+    # The URI created here must exactly match one of the authorized redirect
+    # URIs for the OAuth 2.0 client, which you configured in the API Console. If
+    # this value doesn't match an authorized URI, you will get a
+    # "redirect_uri_mismatch" error.
     flow.redirect_uri = flask.url_for("callback", _external=True)
 
     authorization_url, state = flow.authorization_url(
@@ -153,7 +162,8 @@ def authorize():
 def callback():
     """
     Runs upon return from the OAuth 2.0 authorization server. Fetches and stores
-    the user's credentials, including the access token, refresh token, and allowed scopes.
+    the user's credentials, including the access token, refresh token, and
+    allowed scopes.
     """
 
     # Specify the state when creating the flow in the callback so that it can be
@@ -168,9 +178,8 @@ def callback():
     authorization_response = flask.request.url
     flow.fetch_token(authorization_response=authorization_response)
 
-    # Store credentials in the session.
-    # ACTION ITEM: In a production app, you likely want to save these
-    #              credentials in a persistent database instead.
+    # Store credentials in the session. ACTION ITEM: In a production app, you
+    # likely want to save these credentials in a persistent database instead.
     credentials = flow.credentials
     flask.session["credentials"] = credentials_to_dict(credentials)
 
@@ -191,9 +200,10 @@ def revoke():
     """
 
     if "credentials" not in flask.session:
-        return flask.render_template("addon-discovery.html",
-                                     message="You need to authorize before " +
-                                     "attempting to revoke credentials.")
+        return flask.render_template(
+            "addon-discovery.html",
+            message="You need to authorize before " +
+            "attempting to revoke credentials.")
 
     credentials = google.oauth2.credentials.Credentials(
         **flask.session["credentials"])
@@ -216,8 +226,8 @@ def revoke():
 @app.route("/start-auth-flow")
 def start_auth_flow():
     """
-    Starts the OAuth 2.0 authorization flow. It's important that the
-    template be rendered to properly manage popups.
+    Starts the OAuth 2.0 authorization flow. It's important that the template be
+    rendered to properly manage popups.
     """
 
     return flask.render_template("authorization.html")
@@ -270,23 +280,23 @@ def credentials_to_dict(credentials):
     ### OPTION 1: Unsecured localhost
     # When running locally on unsecured HTTP, use this line to disable
     # OAuthlib's HTTPs verification.
+
     # Important: When running in production *do not* leave this option enabled.
     os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
 
     # Run the application on a local server, defaults to http://localhost:5000.
     # Note: the OAuth flow requires a TLD, *not* an IP address; "localhost" is
-    #   acceptable, but http://127.0.0.1 is not.
+    # acceptable, but http://127.0.0.1 is not.
     app.run(debug=True)
 
     ### OPTION 2: Secure localhost
     # Run the application over HTTPs with a locally stored certificate and key.
-    # Defaults to https://localhost:5000.
+    # Defaults to https://localhost:5000.\
     # app.run(host="localhost",
-    #         ssl_context=("localhost.pem", "localhost-key.pem"),
-    #         debug=True)
+    #   ssl_context=("localhost.pem", "localhost-key.pem"), debug=True)
 
     ### OPTION 3: Production- or cloud-ready server
-    # Start a Gunicorn server, which is appropriate for use in
-    # production or a cloud deployment.
+    # Start a Gunicorn server, which is appropriate for use in production or a
+    # cloud deployment.
     # server_port = os.environ.get("PORT", "8080")
     # app.run(debug=True, port=server_port, host="0.0.0.0")