Module: ObservableThing

Included in:
Jabber::Observable
Defined in:
lib/observable_thing.rb

Overview

This was based on Observable module from Ruby.

Instance Method Summary collapse

Instance Method Details

#add_observer(thing, observer, func = :update) ⇒ Object

Adds an observer for some “thing”.

thing

what will be observed.

observer

the observer.

func

the observer method that will be called (default: :update).



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# File 'lib/observable_thing.rb', line 12

def add_observer(thing, observer, func = :update)
	@things = {} unless defined? @things
	@things[thing] = {} unless ! @things[thing].nil?
	unless observer.respond_to? func
		raise NoMethodError, "observer does not respond to `#{func.to_s}'"
	end
	@things[thing][observer] = func unless @things[thing].include?(observer)
end

#changed(thing, state = true) ⇒ Object

Change the state of some “thing”.

thing

what will have the state changed.

state

the state (default = true).



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# File 'lib/observable_thing.rb', line 68

def changed(thing, state = true)
	@things_state = {} unless defined? @things_state
	@things_state[thing] = state
end

#changed?(thing) ⇒ Boolean

Check the state of some “thing”.

thing: what to have its state checked.

Returns:

  • (Boolean) 


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# File 'lib/observable_thing.rb', line 76

def changed?(thing)
	if defined? @things_state and @things_state[thing]
		true
	else
		false
	end
end

#count_notifications(thing) ⇒ Object

Count the number of notifications for some “thing”.

thing

what has been observed.



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# File 'lib/observable_thing.rb', line 59

def count_notifications(thing)
	return 0 if (! defined?(@things_counter)) or (! @things_counter.include?(thing))
	@things_counter[thing]
end

#count_observers(thing = nil) ⇒ Object

Count the number of observers for some “thing”.

thing

what has been observed (if nil, count all observers).



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# File 'lib/observable_thing.rb', line 43

def count_observers(thing = nil)
	return 0 if ! defined? @things
	size = 0
	if thing.nil?
		@things.each { |thing, hash|
			size += hash.size
		}
	else
		size = @things[thing].size unless @things[thing].nil?
	end
	size
end

#delete_observer(thing, observer) ⇒ Object

Deletes an observer for some “thing”.

thing

what has been observed.

observer

the observer.



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# File 'lib/observable_thing.rb', line 25

def delete_observer(thing, observer)
	@things[thing].delete observer if defined? @things and ! @things[thing].nil?
end

#delete_observers(thing = nil) ⇒ Object

Delete observers for some “thing”.

thing

what has been observed (if nil, deletes all observers).



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# File 'lib/observable_thing.rb', line 32

def delete_observers(thing = nil)
	if thing.nil?
		@things.clear if defined? @things
	else
		@things[thing].clear if defined? @things and ! @things[thing].nil?
	end
end

#notify_observers(thing, *arg) ⇒ Object

Notify all observers of “thing” about something. This will only be enforced if the state of that “thing” is true. Also, if the observer returns the Symbol :delete_me, it will be deleted after being notified.

thing

what has been observed.

args

notification to be sent to the observers of “thing”.



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# File 'lib/observable_thing.rb', line 90

def notify_observers(thing, *arg)
	if changed?(thing)
		if defined? @things and ! @things[thing].nil?
			@things[thing].each { |observer, func|
				increase_counter(thing)
				@thread_store = ThreadStore.new if ! defined? @thread_store
				@thread_store.add Thread.new {
					if observer.send(func, thing, *arg) == :delete_me
						delete_observer(thing, observer)
					end
				}
			}
		end
		changed(thing, false)
	end
end

#pending_notifications? ⇒ Boolean

Is there pending notifications?

Returns:

  • (Boolean) 


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# File 'lib/observable_thing.rb', line 108

def pending_notifications?
	return false if ! defined? @thread_store
	@thread_store.size > 0
end

#wait_notifications ⇒ Object

Wait all notifications



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# File 'lib/observable_thing.rb', line 114

def wait_notifications
	sleep 1 while pending_notifications?
end