api_controller.rb

class APIController < ActionController::API
  include ActionController::HttpAuthentication::Token
  include ActiveSupport::SecurityUtils

  rescue_from ActiveRecord::RecordNotFound, with: :not_found

  def not_found
    api_error(status: 404, errors: 'Not found')
  end

  def api_error(status: 500, errors: [])
    return render status: :unprocessable_entity if errors.empty?

    unless Rails.env.production?
      logger.info errors
      logger.warn errors.full_messages if errors.respond_to? :full_messages
    end

    render json: { errors: errors.as_json }, status: status
  end

  protected

  def authenticate
    authenticate_user! || render_unauthorized
  end

  def authenticate_user!
    token, options = token_and_options(request)
    return false unless token || options
    @user = User.find_by(email: options[:email])
    if @user && secure_compare(@user.authentication_token, token)
      @current_user = @user
    else
      render_unauthorized
    end
  end

  def render_unauthorized
    headers['WWW-Authenticate'] = 'Token realm="Application"'
    api_error(status: 401, errors: 'Unauthorized Access Request')
  end

end