From: Chris Carter <cdcarter@...>
Date: 2007-03-29T21:04:22+09:00
Subject: Re: Inheritance not working as expected

On 3/29/07, KJF <Kevin.Fagan1@gmail.com> wrote:
> I am trying to build up some classes using inheritance but I'm not
> getting the expected results
>
> Here are my classes and test data
>
> class Control
>         attr :attributes, true
>
>         def initialize(x, y, w, h)
>                 @attributes = {
>                         'x'=>x,
>                         'y'=>y,
>                         'h'=>w,
>                         'w'=>h
>                 }
>         end
>
>         def getAttributes
>                 return @attributes
>         end
> end
>
> class StaticTextControl < Control
>
>         def initialize(x, y, w, h, xBorder, yBorder, fontSize, fontMode,
> phrase)
>                 super(x, y, w, h)
>                 @@desc = 'STATIC_TEXT_CONTROL'
>                 @attributes = {
>                         'xBorder'=>xBorder,
>                         'yBorder'=>yBorder,
>                         'fontSize'=>fontSize,
>                         'fontMode'=>fontMode,
>                         'phrase'=>phrase
>                 }
>         end
>
>         def getAttributes
>                 return @attributes.merge(super)
>         end
> end
>
> stc = StaticTextControl.new(1,2,3,4,5,6,7,8,9)
> puts stc.getAttributes
>
>
> When I run the script I get this:
> returning attributes {"phrase"=>9, "xBorder"=>5, "fontSize"=>7,
> "yBorder"=>6, "fontMode"=>8}
> phrase9xBorder5yBorder6fontSize7fontMode8
>
> I am expecting the attributes from the super class to be included as
> well.
> Can anyone tell me what I'm doing wrong?
>
> Thanks.
>
>
>

You call super, which assigns the @attributes hash, then you just
reassign it.  In the subclass you need to add to the hash not
overwrite it.

>                 super(x, y, w, h)
>                 @@desc = 'STATIC_TEXT_CONTROL'
                @attributes.merge( {
                         'xBorder'=>xBorder,
                         'yBorder'=>yBorder,
                         'fontSize'=>fontSize,
                         'fontMode'=>fontMode,
                         'phrase'=>phrase
                })


Chris Carter
concentrationstudios.com
brynmawrcs.com