Locally cached discovery documents may be used as well. To load an API from a local file:
```ruby
+# Output discovery document to JSON
+File.open('my-api.json', 'w') do |f| f.puts MultiJson.dump(client.discovery_document('myapi', 'v1')) end
+
+# Read discovery document and load API
doc = File.read('my-api.json')
-my_api = client.register_discovery_document('myapi', 'v1', doc)
+client.register_discovery_document('myapi', 'v1', doc)
+my_api = client.discovered_api('myapi', 'v1')
```
### Authorization
For server-to-server interactions, like those between a web application and Google Cloud Storage, Prediction, or BigQuery APIs, use service accounts.
+As of version 0.8.3, service accounts can be configured using
+[Application Default Credentials][1], which rely on the credentials being
+available in a well-known location. If the credentials are not present
+and it's being used on a Compute Engine VM, it will use the VM's default credentials.
+
+```ruby
+client.authorization = :google_app_default # in a later version, this will become the default
+client.authorization.fetch_access_token!
+client.execute(...)
+```
+
+This is simpler API to use than in previous versions, although that is still available:
+
```ruby
key = Google::APIClient::KeyUtils.load_from_pkcs12('client.p12', 'notasecret')
client.authorization = Signet::OAuth2::Client.new(
The API client can automatically retry requests for recoverable errors. To enable retries, set the `client.retries` property to
the number of additional attempts. To avoid flooding servers, retries invovle a 1 second delay that increases on each subsequent retry.
+In the case of authentication token expiry, the API client will attempt to refresh the token and retry the failed operation - this
+is a specific exception to the retry rules.
The default value for retries is 0, but will be enabled by default in future releases.
```ruby
client = Google::APIClient.new
-urlshortener = client.discovered_api('urlshortner')
+urlshortener = client.discovered_api('urlshortener')
batch = Google::APIClient::BatchRequest.new do |result|
puts result.data
## Support
Please [report bugs at the project on Github](https://github.com/google/google-api-ruby-client/issues). Don't hesitate to [ask questions](http://stackoverflow.com/questions/tagged/google-api-ruby-client) about the client or APIs on [StackOverflow](http://stackoverflow.com).
+
+[1]: https://developers.google.com/accounts/docs/application-default-credentials