From: "ara.t.howard" <ara.t.howard@...>
Date: 2008-11-07T08:16:32+09:00
Subject: Re: Creating object from hash


On Nov 6, 2008, at 4:03 PM, Robert Klemme wrote:

> On 06.11.2008 21:44, Davi Barbosa wrote:
>> I'm creating an object from a hash using this:
>> class Computer
>>  def initialize(hash)
>>    hash.each do |k,v|
>>      instance_variable_set("@#{k}", v)  ## create and initialize an
>> instance variable for this key/value pair
>>      instance_eval %Q{ class << self ; attr_reader  
>> #{k.intern.inspect}
>> ; end }
>>    end
>>  end
>> end
>> This works fine except if I need to define a method with the same  
>> name
>> of a key (if I need an complicated getter/setter for example). So I
>> added a test to attr_reader line:
>> instance_eval %Q{ class << self ; attr_reader #{k.intern.inspect} ;  
>> end
>> } if !instance_eval %Q{defined? #{k}}
>> As an Object, some methods are defined (like "id"). So "pc =
>> Computer.new({'id' > 1})" does not create the reader for @id and  
>> "pc.id"
>> calls some unwanted method.
>> If I just add "attr_reader :id" everything works. Can I do it  
>> directly,
>> without adding attr_reader (or attr_accessor) every time that I get  
>> an
>> error?
>
> You can make your life easier with Struct:
>
> irb(main):001:0> Comp = Struct.new :id do
> irb(main):002:1* def initialize(h)
> irb(main):003:2> members.each {|m| self[m] = h[m] || h[m.to_sym]}
> irb(main):004:2> end
> irb(main):005:1> end
> => Comp
> irb(main):006:0> c = Comp.new(:id=>133)
> => #<struct Comp id=133>
> irb(main):007:0> d = Comp.new("id"=>133)
> => #<struct Comp id=133>
> irb(main):008:0>
>
> Kind regards
>
> 	robert
>

and even easier with fattr


class Computer
   fattr :foo
   fattr :bar

   def initialize options = {}
     options.each{|k,v| send k, v}
   end
end

a @ http://codeforpeople.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama