From: Robert Klemme <bob.news@...>
Date: 2004-11-16T05:13:28+09:00
Subject: Re: Scope...


"Jeff Wood" <jeffwood@amazon.com> schrieb im Newsbeitrag 
news:4198F01F.5030204@amazon.com...
> Ok, here's a snippet
>
> def parseElement( currentElement, currentNode )
>
>  # Step 1: Load the attributes from currentElement into currentNode
>  currentElement.attributes.each do |name, value|
>    currentNode.attributes[name] = value
>  end
>   # Step 2: Parse the children.
>  currentElement.children.each do |currentChild|
>   if currentChild.kind_of? Text
>      puts "Ignoring #{currentChild.value}"
>    end
>   if currentChild.kind_of? Element
>
>      childNode = JWNode.new( currentChild.name )
>
>      #################################################################
>      # PROBLEM HERE ... currentNode doesn't make it into this scope. #
>      # vvvvvvvvvvvv ##################################################
>      currentNode.children << childNode
>
>      parseElement( currentChild, childNode )
>
>    end
>   end
>
> end
>
> The code is taking an REXML::Element tree ( xml doc ) ... and passing it 
> in with another object.
>
> As I try to add children to the passed in object, I find that currentNode 
> at the "PROBLEM HERE" point is Nil

currentNode must be nil on invocation as there is no assignment and if...end 
does not open a new scope.  If it would, you would get an exception for 
using an undefined variable IMHO.  Or do you happen to have defined a method 
currentNode()?

> I guess I don't understand Ruby's scoping logic as well as I thought I 
> did...  help?

I think you do but you are looking for the error in the wrong place.  I'd 
put a "p currentNode" in the first line of the method and see what it 
prints.

Kind regards

    robert