From: dblack@...
Date: 2007-01-18T03:49:32+09:00
Subject: Re: ActiveRecord find_by_*() - how does it work?

Hi --

On Thu, 18 Jan 2007, Eduardo Scoz wrote:

> Hi guys!
>
> I've been trying to understand how the find_by_*() method on
> ActiveRecord works, but couldn't find anything that could help. I think
> that you guys can probably help me on that.
>
> On Active Record, you can make a call like
>    user.find_by_first_name_and_last_name("eduardo"...)
> and this will generate the sql to send to the database.
>
> But how does that method gets created? ActiveRecord doesn't know what I
> want to find until I actually make the call, and the number of different
> combinations of parameters would probably be infinite for it to be
> created during the object initialization, so (I imagine) the method must
> be created __AFTER__ it was called.
>
> So my question is, is it possible for an object to receive a call to a
> method that doesn't exist, not throw a NoMethodError, and respond to
> that call?

Let me be the first of probably 10 or 15 people to say:

method_missing

:-)


David

-- 
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A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black)
    (See what readers are saying!  http://www.rubypal.com/r4rrevs.pdf)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)