DiscoveryV1

Unofficial helpers and extensions for the Google Discovery V1 API

Gems in the Google API helper, extensions, and examples series:

• discovery_v1
• drive_v3
• sheets_v4

• Contents
• Installation
• Examples
• Important links
  • DiscoveryV1 documenation
  • General API documentation
  • Ruby implementation of the Discovery API
• Usage
  • Obtaining a DiscoveryService
  • Downloading an API discovery document
  • Validating API objects
  • Google Extensions
    • RestDescription Extensions
• Development
• Contributing
• License
• Code of Conduct

Install the gem and add to the application's Gemfile by executing:

bundle add discovery_v1

If bundler is not being used to manage dependencies, install the gem by executing:

gem install discovery_v1

TODO

This Gem's YARD documentation is hosted on rubydoc.info.

• Google Discovery API Overview
• Google Discovery API Reference

• DiscoveryService Class
• All Other Discovery Classes

Detailed API documenation is hosted on rubygems.org.

No credential file is needed to access the discovery service.

discovery_service = DiscoveryV1.discovery_service

The Discovery API provides a list of Google APIs and a machine-readable "Discovery Document" for each API. Both capabilities are provided by Google::Apis::DirectoryV1::DirectoryService instance methods:

• #list_apis returns the list of supported APIs
• #get_rest_api returns the "discovery document" which is a description of a particular version of an api

Each discovery document includes schemas for the objects that can be passed as parameters to methods in that API.

This gem can use the schemas that are part of a discovery document to validate objects that parameters to an API method call.

This can be helpful to troubleshoot invalid requests since requests can become very large and complex.

The DiscoveryV4.validate_object method can be used to validate a request object before an API call. This method requires the following information:

1. the Discovery Document returned from DirectoryService#get_read_api
2. the name of the schema for the object being validated (must be one returned from DirectoryService.object_schema_names)
3. the object being validated

For example, in the Google Sheets API, speradsheets are often updated by calling SheetsService#batch_update_spreadsheet. This API method requires a BatchUpdateSpreadsheetRequest object.

Here is an example that builds a request to write the value 'A' to cell A1 but it contains an error (see if you can spot the error):

require 'discovery_v1'

batch_update_spreadsheet_request = {
  requests: [
    {
      update_cells: {
        rows: [
          { values: [ { user_entered_value: { string_value: 'A' } } ] }
        ],
        fields: '*',
        start: { sheet_id: 0, row_index: '1', column_index: 'A' }
      }
    }
  ],
  response_include_grid_data: false
}

api_name = 'sheets'
api_version = 'v4'
discovery_service = DiscoveryV1.discovery_service
rest_description = discovery_service.get_rest_api(api_name, api_version)
schema_name = 'batch_update_spreadsheet_request'

begin
  DiscoveryV1.validate_object(rest_description:, schema_name:, object: batch_update_spreadsheet_request)
rescue => e
  puts e.message
end

Running this example shows the following output:

Object does not conform to batch_update_spreadsheet_request: value at `/requests/0/update_cells/start/row_index` is not an integer

The DiscoveryV1.validate_object method can be used to validate objects prior to using them in a Google API request described by the Discovery service.

This method takes a schema_name and an object to validate. Schema names for a schema can be listed using DiscoveryV1.object_schema_names.

validate_object will either return true if object conforms to the schema OR it will raise a RuntimeError noting where the object structure did not conform to the schema. RuntimeError#message will give details about where the structure did not conform.

The DiscoveryV1::GoogleExtensions module provides extensions to the Google::Apis::DiscoveryV1 modules and classes to simplify use of the SheetsV4 API.

These extensions are not loaded by default and are not required to use other parts of this Gem. To enable these extension, you must:

require 'discovery_v1/google_extensions'

Convenience methods are been added to Google::Apis::DiscoveryV1::RestDescription:

• RestDescription#object_schema_names: The names of the schemas defined by this RestDescription.
• RestDescription#validate_object: Raises an error if the given object does not conform to the named schema.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/discovery_v1. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the DiscoveryV1 project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.