From: Stefano Crocco <stefano.crocco@...>
Date: 2008-07-01T01:46:06+09:00
Subject: Re: is it possible to create a hash dynamically?

On Monday 30 June 2008, aidy wrote:
> Hi,
>
> I am trying to build a dynamic hash map
>
> <CODE>
>   def extract(xml, path)
>       require 'rexml/document'
>       xml = xml.to_s.gsub("utf-16", "utf-8")
>       doc = REXML::Document.new(xml)
>       doc.root.each_element(path) do |element|
>           element.each_element do |node|
>           puts "name: #{node.name} text: #{node.text}"
>           @xml_data = {node.name => node.text}
>         end
>       end
>       return @xml_data
>     end
> </CODE>
>
> However, the @xml_data is always returning 1 element
>
> Thanks
>
> Aidy

The problem is in the line

@xml_data = {node.name => node.text}

At each iteration, you discard the old content of the variable and replace it 
with a new hash. This way, at the end of the cycle, the @xml_data will be a 
hash containing only the text of the last node.

To do what you want, you should set @xml_data to an empty hash outside the 
outer each, then store the new node in the hash at each iteration:

def extract(xml, path)
  require 'rexml/document'
  xml = xml.to_s.gsub("utf-16", "utf-8")
  doc = REXML::Document.new(xml)
  @xml_data = {}
  doc.root.each_element(path) do |element|
      element.each_element do |node|
      puts "name: #{node.name} text: #{node.text}"
      @xml_data[node.name] => node.text}
    end
  end
  return @xml_data
end

By the way, are you sure @xml_data needs to be an instance variable? From the 
way you use it in the piece of code you posted, it seems it should be a local 
variable.

I hope this helps

Stefano