MUDBytes Community - Viewing Topic: Observer pattern

Runter
Wizard

Group: Members
Posts: 1,850
Joined: Jun 1, 2006

#1 id:29110 Posted Jul 18, 2009, 1:01 am

After the discussion about using observer on another thread I wrote a little code to let me use blocks/closures. Was wondering if anybody else had done this and had an insight on its actual application?

Code (text):

 
obj.add_observer(:type_selected) do |data|
  ### do something with data variable
end

Basically the code block is doing the observing and will be executed. :type_selected is the filter so it doesn't receive all types of data. Seems interesting, although I think it may just have the same (or even less) usefulness. (On a side note, though, it isn't really much different except I can attached loaded script directly to an event.)

edit: There's a standard library implementing the pattern in Ruby, but it doesn't allow blocks as observers.

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Last edited Jul 18, 2009, 1:18 am by Runter

David Haley Wizard Group: Members Posts: 6,874 Joined: Jun 30, 2007	#2 id:29136 Posted Jul 18, 2009, 10:31 am
	Isn't it basically the same as passing in an anonymous function instead of a named function?
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Runter Wizard Group: Members Posts: 1,850 Joined: Jun 1, 2006	#3 id:29144 Posted Jul 18, 2009, 2:11 pm
	David Haley said: Isn't it basically the same as passing in an anonymous function instead of a named function? I suppose. The block itself is an object so there's really not much difference between it and any other object as an observer. Interestingly, it can return values back to the observed, though.
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