From: Gavin Sinclair <gsinclair@...>
Date: 2008-08-15T23:12:07+09:00
Subject: Re: Best practice for set-and-test idiom?

On Aug 15, 3:51 am, Kevin Nolan <kpno...@insgraph.com> wrote:
>
>      unless (ar = Model.find(...)).nil?
>         val = ar.attribute
>      else
>         val = DEFAULT
>
>    or the equivalent expression.
>
> It seems to me that this is very unRuby-like and I don't see any similar
> usages in any of the code-bases in which I have looked.
>
> Will someone please provide a counter-example?

Does the Model.find(...) need to be buried in a test condition?  If
it's retrieving worthwhile data, it's worth a line of its own.

  model = Model.find(...)
  val = (model && model.attribute) || DEFAULT

The second line could be called idiomatic Ruby.  Whether it appeals to
you or not, I can't predict :)

For situations where more complex processing is required before
setting the variable, I am a _big_ fan of these:

  val =
    if condition then
      processing
      processing
      value1
    else
      processing
      value2
    end

  val =
    case x
    when 1: ...
    when 2: ...
    ...
    end

Cheers,
Gavin