Rails - Aug 2006 - How can I make a property aware of changes on another?

I have a model that needs to update a property whenever another property 
changes, i.e. changing the model ''type'' property updates the 
''description'' property with another value.
I don''t know how to get access to the underlying fields handled by
rails
within a model class.

Thanks,

Daniel

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Hello Daniel,
    It sounds like you are looking for the magic that makes the Observer 
design pattern happen. In Ruby this is done using the Observable module. 
Example code here ; 
http://www.oreillynet.com/ruby/blog/2006/01/ruby_design_patterns_observer.html

    FYI, I have NOT tried this under rails, but, I would be intrigued to 
hear how you get along with it. Let us all know how it goes ;)
    Regards
    Stef

Daniel Mantilla wrote:
> I have a model that needs to update a property whenever another property 
> changes, i.e. changing the model ''type'' property updates
the
> ''description'' property with another value.
> I don''t know how to get access to the underlying fields handled by
rails
> within a model class.
>
> Thanks,
>
> Daniel
>
>   

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