From: Martin DeMello <martindemello@...>
Date: 2007-03-17T04:12:46+09:00
Subject: Re: attr_protected macro

On 3/16/07, gaurav bagga <gaurav.v.bagga@gmail.com> wrote:
> Hi All,
>
>  I was going through a blog where I found "Do this by calling the
> attr_protected macro in your model class definition" what do you mean
> by macro here.
>  Is it a method?

First a bit of background: ruby has no real 'compile' phase; it
executes code within a source file as it reads it. Code within a class
Foo/end block is executed in the scope of the class Foo. Thus def
method..end is actual code that defines a method and adds it to the
class, etc.

Some methods, loosely called 'macros', define other methods on the fly
when they're executed, or do other things commonly lumped under
"metaprogramming". For instance, in the following code

class Foo
  attr_accessor :bar
end

attr_accessor is a method (of the Class class, to be precise), to
which the argument :bar is passed. When executed, it generates the
following two methods

def bar
  @bar
end

def bar=(x)
  @bar = x
end

Not sure exactly what attr_protected does, but it's somewhere along
the same lines.

martin