From: "Dan Stevens (IAmAI)" <dan.stevens.iamai@...>
Date: 2007-07-06T07:28:09+09:00
Subject: Re: Calling an arbitrary method as and when an array's contents change

> It sounds like you might be able to set up something like this with Observer.

Ah! I'd forgotten about the observer pattern. That should do the trick. Thanks!

On 05/07/07, Gregory Brown <gregory.t.brown@gmail.com> wrote:
> On 7/5/07, Dan Stevens (IAmAI) <dan.stevens.iamai@gmail.com> wrote:
> > I have a collection class that extends the Array class and I wish to
> > have a particular method to be called whenever the contents of an
> > instance of the class change. Can anyone advise on how I can achieve
> > this?
> >
> > I'm aware that I can compare #hash with a previous saved value to
> > determine if the contents of the instance have changed since the last
> > time #hash was called. Therefore, if I can find a means of calling an
> > arbitrary method or piece of code every time any method is called on
> > the instance, I could achieve what I'm after. Can I override
> > Object#send?
>
> It sounds like you might be able to set up something like this with Observer.
> http://www.ruby-doc.org/stdlib/libdoc/observer/rdoc/index.html
>
>