From: Robert Dober <robert.dober@...>
Date: 2008-03-03T20:09:44+09:00
Subject: Re: Understanding ruby classes

On Mon, Mar 3, 2008 at 9:07 AM, Damjan Rems <d_rems@yahoo.com> wrote:
>
>  This question is all about me not understanding how ruby classes work.
>
>  I have three print classes. myPrint which is abstract class and
>  implements common methods for other two classes which are myPrint2PDF
>  and myPrint2HTML.
Which means it just factorizes work, I suggest you make it a module then
module MyPrint...
>
They implement all the troubles of output to PDF or
>  HTML format. Without too much code, implementation looks like this:
>
>  class myPrint
>  def printHDR
>  end
>  ....
>  end
>
>  class myPrint2PDF
         include MyPrint
         include Workerbee ## see below
>  ....
>  end
>
>  class myPrint2HTML
        include MyPrint
        include Workerbee
>  ....
>  end
>
>
>  Then I have fourth class which implements the job which has to be done.
Should probably still be a module, let us name it Workerbee
>
>  class myPrint001 << myPrint2PDF
>  def printHDR
>   image 'image.jpg' 20, 1
>   print 'some header text' 1,5
>   ...
>  end
>  def doJob
>   print 'some text' 1,5
>  end
>  end
>
>  Here is my catch 22. I would REALLY like to call my implementation
>  class like this:
>  pr = myPrint001 :format => 'HTML' or
>  pr = myPrint001 :format => 'PDF'
pr = MyPrint2PDF or
pr = MyPrint2HTML
>  pr.doJob
>
>  I have made statement 'class myPrint001 << myPrint2PDF' intentionaly
>  wrong and I know it does not provide the real solution, but this is how
>  it works for now.
>
>  What would be the best (ruby) solution to this problem.
Actually that has not much to do with Ruby, it seems your design is a
little bit flawed.

HTH
Robert


-- 
http://ruby-smalltalk.blogspot.com/

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