Add a small web sample showing incremental authorization & use of APIs

Gemfile

@@ -16,6 +16,11 @@ group :development do
   gem 'launchy', '~> 2.4'
   gem 'dotenv', '~> 2.0'
   gem 'fakefs', '~> 0.6', require: "fakefs/safe"
+  gem 'google-id-token', '~> 1.3'
+  gem 'os', '~> 0.9'
+  gem 'rmail', '~> 1.1'
+  gem 'sinatra', '~> 1.4'
+  gem 'redis', '~> 3.2'
 end
 
 platforms :jruby do

samples/cli/Gemfile

@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'google-api-client', '~> 0.9.pre4'
+gem 'google-api-client', '~> 0.9'
 gem 'thor', '~> 0.19'
 gem 'os', '~> 0.9'
 gem 'rmail', '~> 1.1'

samples/web/Gemfile

@@ -0,0 +1,7 @@
+source 'https://rubygems.org'
+
+gem 'google-api-client', '~> 0.9'
+gem 'google-id-token', '~> 1.3'
+gem 'sinatra', '~> 1.4'
+gem 'redis', '~> 3.2'
+gem 'dotenv'

samples/web/README.md

@@ -0,0 +1,44 @@
+# API Samples
+
+This directory contains a simple Sinatra web app illustrating how to use the client
+in a server-side web environment.
+
+It illustrates a few key concepts:
+
+* Using [Google Sign-in](https://developers.google.com/identity) for authentication.
+* Using the [googleauth gem](https://github.com/google/google-auth-library-ruby) to
+  request incremental authorization as more permissions are needed.
+
+# Setup
+
+* Create a project at https://console.developers.google.com
+* Go to the `API Manager` and enable the `Drive` and `Calendar` APIs
+* Go to `Credentials` and create a new OAuth Client ID of type 'Web application'
+    * Use `http://localhost:4567/oauth2callback` as the redirect URL
+    * Use `http://localhost:4567` as the JavaScript origin
+
+Additional details on how to enable APIs and create credentials can be
+found in the help guide in the console.
+
+## Example Environment Settings
+
+For convenience, application credentials can be read from the shell environment
+or placed in a .env file.
+
+After setup, your .env file might look something like:
+
+```
+GOOGLE_CLIENT_ID=479164972499-i7j6av7bp2s4on5ltb7pjXXXXXXXXXX.apps.googleusercontent.com
+GOOGLE_CLIENT_SECRET=JBotCTG5biFWGzXXXXXXXXXX
+```
+
+# Running the samples
+
+To start the server, run
+
+```
+ruby app.rb
+```
+
+Open `http://localhost:4567/` in your browser to explore the sample.
+

samples/web/app.rb

@@ -0,0 +1,120 @@
+# Copyright 2015 Google Inc.
+#
+# 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.
+
+require 'sinatra'
+require 'googleauth'
+require 'googleauth/stores/redis_token_store'
+require 'google/apis/drive_v3'
+require 'google/apis/calendar_v3'
+require 'google-id-token'
+require 'dotenv'
+
+LOGIN_URL = '/'
+
+configure do
+  Dotenv.load
+
+  Google::Apis::ClientOptions.default.application_name = 'Ruby client samples'
+  Google::Apis::ClientOptions.default.application_version = '0.9'
+  Google::Apis::RequestOptions.default.retries = 3
+
+  enable :sessions
+  set :show_exceptions, false
+  set :client_id, Google::Auth::ClientId.new(ENV['GOOGLE_CLIENT_ID'],
+                                             ENV['GOOGLE_CLIENT_SECRET'])
+  set :token_store, Google::Auth::Stores::RedisTokenStore.new(redis: Redis.new)
+end
+
+helpers do
+  # Returns credentials authorized for the requested scopes. If no credentials are available,
+  # redirects the user to authorize access.
+  def credentials_for(scope)
+    authorizer = Google::Auth::WebUserAuthorizer.new(settings.client_id, scope, settings.token_store)
+    user_id = session[:user_id]
+    redirect LOGIN_URL if user_id.nil?
+    credentials = authorizer.get_credentials(user_id, request)
+    if credentials.nil?
+      redirect authorizer.get_authorization_url(login_hint: user_id, request: request)
+    end
+    credentials
+  end
+
+  def resize(url, width)
+    url.sub(/s220/, sprintf('s%d', width))
+  end
+end
+
+# Home page
+get('/') do
+  @client_id = settings.client_id.id
+  erb :home
+end
+
+# Log in the user by validating the identity token generated by the Google Sign-In button.
+# This checks that the token is signed by Google, current, and is intended for this application.
+#
+post('/signin') do
+  audience = settings.client_id.id
+  # Important: The google-id-token gem is not production ready. If using, consider fetching and
+  # supplying the valid keys separately rather than using the built-in certificate fetcher.
+  validator = GoogleIDToken::Validator.new
+  claim = validator.check(params['id_token'], audience, audience)
+  if claim
+    session[:user_id] = claim['sub']
+    session[:user_email] = claim['email']
+    200
+  else
+    logger.info('No valid identity token present')
+    401
+  end
+end
+
+# Retrieve the 10 most recently modified files in Google Drive
+get('/drive') do
+  drive = Google::Apis::DriveV3::DriveService.new
+  drive.authorization = credentials_for(Google::Apis::DriveV3::AUTH_DRIVE)
+  @result = drive.list_files(page_size: 10,
+                             fields: 'files(name,modified_time,web_view_link),next_page_token')
+  erb :drive
+end
+
+# Retrieve the next 10 upcoming events from Google Calendar
+get('/calendar') do
+  calendar = Google::Apis::CalendarV3::CalendarService.new
+  calendar.authorization = credentials_for(Google::Apis::CalendarV3::AUTH_CALENDAR)
+  calendar_id = 'primary'
+  @result = calendar.list_events(calendar_id,
+                                 max_results: 10,
+                                 single_events: true,
+                                 order_by: 'startTime',
+                                 time_min: Time.now.iso8601)
+  erb :calendar
+end
+
+
+# Callback for authorization requests. This saves the autorization code and
+# redirects back to the URL that originally requested authorization. The code is
+# redeemed on the next request.
+#
+# Important: While the deferred approach is generally easier, it doesn't play well
+# with developer mode and sinatra's default cookie-based session implementation. Changes to the
+# session state are lost if the page doesn't render due to error, which can lead to further
+# errors indicating the code has already been redeemed.
+#
+# Disabling show_exceptions or using a different session provider (E.g. Rack::Session::Memcache)
+# avoids the issue.
+get('/oauth2callback') do
+  target_url = Google::Auth::WebUserAuthorizer.handle_auth_callback_deferred(request)
+  redirect target_url
+end

samples/web/views/calendar.erb

@@ -0,0 +1,34 @@
+<%#
+# Copyright 2016 Google Inc.
+#
+# 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.
+%>
+<section>
+  <h5>Next 10 events</h5>
+  <table class="">
+    <thead>
+    <tr>
+      <th class="">Time</th>
+      <th class="">Summary</th>
+    </tr>
+    </thead>
+    <tbody>
+    <% @result.items.each do |event| %>
+        <tr>
+          <td class=""><%= event.start.date_time || event.start.date %></td>
+          <td class=""><%= event.summary %></td>
+        </tr>
+    <% end %>
+    </tbody>
+  </table>
+</section>

samples/web/views/drive.erb

@@ -0,0 +1,33 @@
+<%#
+# Copyright 2016 Google Inc.
+#
+# 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.
+%>
+
+<h5>10 most recently modified files</h5>
+<table class="">
+  <thead>
+    <tr>
+      <th class="">Name</th>
+      <th class="">Last Modified</th>
+    </tr>
+  </thead>
+  <tbody>
+  <% @result.files.each do |file| %>
+      <tr>
+        <td class=""><a href="<%= file.web_view_link %>"><%= file.name %></a></td>
+        <td class=""><%= file.modified_time %></td>
+      </tr>
+  <% end %>
+  </tbody>
+</table>

samples/web/views/home.erb

@@ -0,0 +1,35 @@
+<%#
+# Copyright 2016 Google Inc.
+#
+# 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.
+%>
+<div class="g-signin2" data-onsuccess="onSignIn"></div>
+<script>
+function onSignIn(googleUser) {
+  var id_token = googleUser.getAuthResponse().id_token;
+  var formData = new FormData();
+  formData.append('id_token', id_token);
+  var req = new XMLHttpRequest();
+  req.addEventListener("load", function() {
+    console.log("Log in successful");
+    // Successful login...
+  });
+  req.addEventListener("error", function() {
+    console.log("Log in failed");
+    // Handle error...
+  });
+  req.addEventListener()
+  req.open("POST", "/signin");
+  req.send(formData);
+}
+</script>

samples/web/views/layout.erb

@@ -0,0 +1,40 @@
+<%#
+# Copyright 2016 Google Inc.
+#
+# 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.
+%>
+<html>
+  <head>
+    <script src="https://apis.google.com/js/platform.js" async defer></script>
+    <meta name="google-signin-client_id" content="<%= @client_id %>">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <style type="text/css">
+      .navigation a {
+        padding: 10px;
+      }
+      .main {
+        padding: 10px;
+      }
+    </style>
+  </head>
+  <body>
+    <div class="navigation">
+      <a href="/">Home</a>
+      <a href="/drive">Google Drive Sample</a>
+      <a href="/calendar">Google Calendar Sample</a>
+    </div>
+    <div class="main">
+      <%= yield %>
+    </div>
+  </body>
+</html>