Module Publisher
In: lib/utility/publisher.rb
Publisher dot/f_57.png

Publisher is a variation on Ruby‘s Observable. We do not keep track of any changed state; instead we assume that by virtue of calling publish we have changed state. We do not allow serialization of subscribers. We allow a Publisher to have multiple publications and maintain separate lists of subscribers for each one.

Methods

publish   subscribe   subscriber_count   unsubscribe   unsubscribe_all  

Public Instance methods

publish(*arg)

If this object‘s changed state is true, invoke the update method in each currently associated subscriber in turn, passing it the given arguments. The changed state is then set to false.

[Source]

# File lib/utility/publisher.rb, line 65
  def publish(*arg)
    if defined? @subscribers
      @subscribers.dup.each do |s|
        if s.respond_to?(:to_int)
          Engine.instance.db.get(s).update(*arg)
        else
          s.update(*arg)
        end
      end
    end
  end
subscribe(subscriber)

Add subscriber as an subscriber on this object. subscriber will now receive notifications.

[Source]

# File lib/utility/publisher.rb, line 30
  def subscribe(subscriber)
    @subscribers ||= []
    if !subscriber.respond_to?(:to_int) && !subscriber.respond_to?(:update)
      raise NoMethodError, "subscriber needs to respond to 'update'"
    end
    @subscribers.push subscriber
  end
subscriber_count()

Count of subscribers to this object.

[Source]

# File lib/utility/publisher.rb, line 56
  def subscriber_count
    @subscribers ? @subscribers.size : 0
  end
unsubscribe(subscriber)

Delete subscriber as a subscriber on this object. It will no longer receive notifications.

[Source]

# File lib/utility/publisher.rb, line 42
  def unsubscribe(subscriber)
    @subscribers.delete subscriber if defined? @subscribers
  end
unsubscribe_all()

Delete all subscribers associated with this object.

[Source]

# File lib/utility/publisher.rb, line 49
  def unsubscribe_all
    @subscribers.clear if defined? @subscribers
  end

[Validate]