Class: BackgroundLite::ActiveMessagingHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/background_lite/core_ext/handlers/active_messaging_handler.rb

Overview

This background handler sends the method as well as the arguments through ActiveMessaging to the background poller. If you don’t use the ActiveMessaging plugin, then this handler won’t work.

To make the background_lite plugin work with ActiveMessaging, you need to put the following processor in app/processors:

class BackgroundProcessor < ApplicationProcessor
  subscribes_to :background

  def on_message(message)
    puts "BackgroundProcessor"
    BackgroundLite::ActiveMessagingHandler.execute(message)
  end
end

Constant Summary collapse

@@queue_name =

The ActiveMessaging queue name through which the message should be serialized.

:background

Class Method Summary collapse

Class Method Details

.decode(message) ⇒ Object

Decodes a marshalled message which was previously sent over ActiveMessaging. Returns an array containing the object, the method name as a string, and the method arguments.



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# File 'lib/background_lite/core_ext/handlers/active_messaging_handler.rb', line 37

def self.decode(message)
  begin
    object, method, args, transaction_id = Marshal.load(message)
  rescue ArgumentError => e
    # Marshal.load does not trigger const_missing, so we have to do this
    # ourselves.
    e.message.split(' ').last.constantize
    retry
  end
  [object, method, args, transaction_id]
end

.execute(message) ⇒ Object

Executes a marshalled message which was previously sent over ActiveMessaging, in the context of the object, with all the arguments passed.



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# File 'lib/background_lite/core_ext/handlers/active_messaging_handler.rb', line 52

def self.execute(message)
  logger = BackgroundLite::Config.default_logger
  begin
    object, method, args, transaction_id = self.decode(message)
    if logger.debug?
      logger.debug "--- executing method: #{method}"
      logger.debug "--- with variables: #{args.inspect}"
      logger.debug "--- in object: #{object.class.name}, #{object.id}"
      logger.debug "--- Transaction ID: #{transaction_id}"
    end
    object.send(method, *args)
    logger.debug "--- it happened!" if logger.debug?
  rescue Exception => e
    logger.fatal e.message
    logger.fatal e.backtrace
    "BackgroundLite::#{BackgroundLite::Config.default_error_reporter.to_s.camelize}ErrorReporter".constantize.report(e)
    raise e
  end
end

.handle(object, method, args, options = {}) ⇒ Object

Marshals the method and the arguments and sends it through ActiveMessaging to the background processor.

Options

queue

The name of the queue to use to send the message to the background process.



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# File 'lib/background_lite/core_ext/handlers/active_messaging_handler.rb', line 30

def self.handle(object, method, args, options = {})
  ActiveMessaging::Gateway.publish((options[:queue] || self.queue_name).to_sym, Marshal.dump([object, method, args, options[:transaction_id]]))
end