From: Florian Frank <flori@...>
Date: 2010-04-29T02:23:57+09:00
Subject: Re: Overload the normal behavior of an object/instance in string

On 28/04/2010 19:03, Walle Wallen wrote:
> Long story short. I'm trying to overload the normal behavior of an
> object/instance in a string. Instead of replying "<Test:0x101121db0>" I
> would like it too return a specific string, or something similar. I have
> tried to overload inspect, and it seems to work pretty well, except when
> using the object with puts or in a string "#{p}".
>
> My english ain't good, but I hope you understand the principle of what I
> am trying to achieve.
>
> [code]
> class Test
>   def inspect
>      puts "this is a test"
>   end
> end
>
> p = Test.new
> this is a test
>   
>>> p
>>>       
> this is a test
>
> puts p
> #<Test:0x101121db0>
>
>   
>>> "#{p}"
>>>       
> => "#<Hejsan:0x1010fd7f8>"
> [/code]
>   
You should return strings from these methods:

class Test
  def inspect
    "this is a test" # return the string, don't output it
  end

  def to_s
    "this is another test"
  end
end

Then ruby can call Test#inspect or Test#to_s as it desires:

p Test.new # outputs: this is a test
puts Test.new # outputs: this is another test

-- 
Florian Frank