Service objects

A service object executes one action of your domain logic. Use it instead of a large block of code in a controller or model.

Structure

Inherit from EasyExtensions::BaseService. It includes EasyExtensions::Callable, which defines the class method .call(...): it builds the service with the given arguments and runs the instance method call.

Name the class as a plain command, such as CreateUser or RegisterAccount, without a Service suffix. Put the file in app/services/ of your plugin. Prefix the name or wrap it in a module named after your plugin (see Prefixes).

call returns true or false, or an object (or self) when the service creates or retrieves something.

Example

EasyExtensions::JWT::GenerateAuthToken (app/services/easy_extensions/jwt/generate_auth_token.rb) takes a user and returns a token:

module EasyExtensions
  module JWT
    class GenerateAuthToken < EasyExtensions::BaseService

      # @param [User] user
      def initialize(user: User.current)
        super()
        @user = user
      end

      def call
        EasyExtensions::JWT.encode(payload)
      end

      private

      attr_reader :user

      def payload
        {
          user_id: user.id,
          user_login: user.login,
        }
      end

    end
  end
end

Call it with its arguments:

token = EasyExtensions::JWT::GenerateAuthToken.call(user: User.find(1))