Google Spreadsheet を Ruby で OAuth を使って操作するサンプル

Gemfile

source 'http://rubygems.org'

gem 'google-api-client', '>= 0.6'
gem 'google_drive'

spreadsheet-sample.rb

#!/usr/bin/env ruby
#
# 1. Developers Console にログインして、プロジェクトを作成する
# 2. API -> Drive API を有効にする
# 3. クライアントIDを作成する
#    3-1. アプリケーションの種類は Installed application を選択する
#    3-2. タイプは **その他** を選択
# 4. 作成したクライアントIDのページにある **JSONをダウンロード** を押して、JSONファイルをダウンロードする
#    アプリのディレクトリに client_secrets.json におく
# 5. bundle install
# 6. bundle exec ruby spreadsheet-sample.rb
#

# Copyright (C) 2012 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 'rubygems'
require 'google/api_client'
require 'google/api_client/client_secrets'
require 'google/api_client/auth/file_storage'
require 'google/api_client/auth/installed_app'
require 'google_drive'

CREDENTIAL_STORE_FILE = "#{$0}-oauth2.json"

# Handles authentication and loading of the API.
def setup()
  client = Google::APIClient.new(:application_name => 'Ruby spreadsheet sample',
      :application_version => '1.0.0')

  # FileStorage stores auth credentials in a file, so they survive multiple runs
  # of the application. This avoids prompting the user for authorization every
  # time the access token expires, by remembering the refresh token.
  # Note: FileStorage is not suitable for multi-user applications.
  file_storage = Google::APIClient::FileStorage.new(CREDENTIAL_STORE_FILE)
  if file_storage.authorization.nil?
    client_secrets = Google::APIClient::ClientSecrets.load
    # The InstalledAppFlow is a helper class to handle the OAuth 2.0 installed
    # application flow, which ties in with FileStorage to store credentials
    # between runs.
    flow = Google::APIClient::InstalledAppFlow.new(
      :client_id => client_secrets.client_id,
      :client_secret => client_secrets.client_secret,
      :scope => %w(
        https://www.googleapis.com/auth/drive
        https://docs.google.com/feeds/
        https://docs.googleusercontent.com/
        https://spreadsheets.google.com/feeds/
      ),
    )
    client.authorization = flow.authorize(file_storage)
  else
    client.authorization = file_storage.authorization
  end

  return client
end

client = setup()
session = GoogleDrive.login_with_oauth(client.authorization.access_token)
ws = session.spreadsheet_by_key("YOUR_SPREADSHEET_ID_HERE").worksheets[0]

# dump a cell
p ws[1,1] 

# update a cell
ws[5,5] = "new"
ws.save

# dump all cells
pp ws.rows

client_secrets.json は Google::APIClient::ClientSecrets.load 時に読まれる。.load の引数で指定して任意のパスにも置ける。

Google::APIClient::ClientSecrets.load('config/client_secrets.json')

CREDENTIAL_STORE_FILE で指示されたファイルが存在しない場合、新しいaccess tokenを取得するためにブラウザを開いて許可された後、CREDENTIAL_STORE_FILE に access tokenをキャッシュする。