lib/google/api_client/auth/file_storage.rb

   1 # Copyright 2013 Google Inc.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #      http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 require 'json'
  16 require 'signet/oauth_2/client'
  17
  18 module Google
  19   class APIClient
  20     ##
  21     # Represents cached OAuth 2 tokens stored on local disk in a
  22     # JSON serialized file. Meant to resemble the serialized format
  23     # http://google-api-python-client.googlecode.com/hg/docs/epy/oauth2client.file.Storage-class.html
  24     #
  25     class FileStorage
  26       # @return [String] Path to the credentials file.
  27       attr_accessor :path
  28
  29       # @return [Signet::OAuth2::Client] Path to the credentials file.
  30       attr_reader :authorization
  31
  32       ##
  33       # Initializes the FileStorage object.
  34       #
  35       # @param [String] path
  36       #    Path to the credentials file.
  37       def initialize(path)
  38         @path = path
  39         self.load_credentials
  40       end
  41
  42       ##
  43       # Attempt to read in credentials from the specified file.
  44       def load_credentials
  45         if File.exists? self.path
  46           File.open(self.path, 'r') do |file|
  47             cached_credentials = JSON.load(file)
  48             @authorization = Signet::OAuth2::Client.new(cached_credentials)
  49             @authorization.issued_at = Time.at(cached_credentials['issued_at'])
  50             if @authorization.expired?
  51               @authorization.fetch_access_token!
  52               self.write_credentials
  53             end
  54           end
  55         end
  56       end
  57
  58       ##
  59       # Write the credentials to the specified file.
  60       #
  61       # @param [Signet::OAuth2::Client] authorization
  62       #    Optional authorization instance. If not provided, the authorization
  63       #    already associated with this instance will be written.
  64       def write_credentials(authorization=nil)
  65         @authorization = authorization unless authorization.nil?
  66
  67         unless @authorization.refresh_token.nil?
  68           hash = {}
  69           %w'access_token
  70            authorization_uri
  71            client_id
  72            client_secret
  73            expires_in
  74            refresh_token
  75            token_credential_uri'.each do |var|
  76             hash[var] = @authorization.instance_variable_get("@#{var}")
  77           end
  78           hash['issued_at'] = @authorization.issued_at.to_i
  79
  80           File.open(self.path, 'w', 0600) do |file|
  81             file.write(hash.to_json)
  82           end
  83         end
  84       end
  85     end
  86   end
  87 end