Service Filters

Service Filters provides ActionController-style filter support to service instances, specifically adding before_filter, after_filter, and around_filter.

require 'lib/foo/user.pb'

class Foo::UserService
  before_filter :start_request_timer
  after_filter :end_request_timer
  around_filter :benchmark_request

  # Provide a list of rpc methods to call (or exclude calling) for the given filter(s).
  # The following two filters are essentially equivalent.
  before_filter :verify_user_present, :only => [ :update, :delete ]
  before_filter :verify_user_present, :except => [ :find, :create ]

  # Using if/unless filters options to achieve the same goal, reporting a login after the login has been processed.
  # Note that you can provide a method name or lambda, but you must return a boolean value.
  after_filter :report_login, :only => :login, :if => :user_found?
  after_filter :report_login, :only => :login, :if => lambda { |service| service.response.user_guid.present? }
  after_filter :report_login, :only => :login, :unless => :user_missing?
  after_filter :report_login, :only => :login, :unless => lambda { |service| service.response.user_guid.empty? }

  #... rpc instance methods

  private

  def start_request_timer
    @time_start = Time.now
  end

  def end_request_timer
    @time_end = Time.now
    log_info { ... }
  end

  def benchmark_request
    Benchmark.benchmark do
      yield
    end
  end
end