Rails - Mar 2008 - validate_on_update compare old value to new value

Hello,
After a model has been saved I want to prevent some of it''s fields
from being updated. I was going to do this by overriding
validate_on_update but I don''t know how to access the old value to
compare it to the new value.
Cheers,
Ewan
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ewanmcdougall-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org
wrote:
> Hello,
> After a model has been saved I want to prevent some of it''s fields
> from being updated. I was going to do this by overriding
> validate_on_update but I don''t know how to access the old value to
> compare it to the new value.
> Cheers,
> Ewan
>   
How about overriding the setter methods for those fields you want to 
lock.  Something like...

def title=(t)
   self[:title] = t if self.new_record?
end



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Hello Jon,
Thanks for the reply.
I made the attribute read only doing

attr_readonly :title

Ewan
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