From: "David A. Black" <dblack@...>
Date: 2009-08-28T20:24:19+09:00
Subject: Re: Mass Assignment on Clas

Hi --

On Fri, 28 Aug 2009, Pete Moran wrote:

> Hi there,
>
> I am a total newbie to Ruby, so please bare with me.
>
> I want to be able to be able to initialise a Class with a hash.  For
> instance If I have the class
>
> class Vehicle
>  attr_accessor :vtype, :description, :vehicle, :capacity
> end
>
> I want to be able to do
>
> Vehicle.new(:vtype => 'ECAR', :description => 'Great Car', :vehicle =>
> 'Ford Focus', :capacity => '10');
>
> Now I could do something like
>
> def initialize(items)
>     @vtype = items[:vtype]
>     @description = items[:description]
>     @vehicle = items[:vehicle]
>     @capacity = items[:capacity]
> #     puts items.inspect
>   end
>
> But I was wondering if there was a more generic way of doing this
> without specifically defining each variable in initialize? I think
> ActiveRecord does something similar!

How about:

   def initialize(items)
     items.each do |key,value|
       instance_variable_set("@#{key}", value)
     end
   end

(possible with some checking to make sure they're what you want).


David

-- 
David A. Black / Ruby Power and Light, LLC / http://www.rubypal.com
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