From: "Muhammet S. AYDIN" <mengukagan@...>
Date: 2011-12-22T04:56:17+09:00
Subject: sort optimization questions

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hello everyone,

i have a model class Page in my rails application which is defined like
this:

class Page < ActiveRecord::Base
  attr_accessor :children
  # relationships here..
end

and a NodeList class to sort this pages based on their parent_id
attributes: http://pastie.org/private/rbq05vzkc7wgyan8pcdrw

here is a simple example of how i'm using them:

node_list = NodeList.new(Page.all())
@pages_list = node_list.get_nodes()

i also have a helper method to print the tree:

def print_children(nodes)
    retval = "<ul>"
    nodes.each do |node|
      retval += "<li id=\"page_#{node.id}\"><a
href=\"/documents/#{node.document_id}/pages/#{node.id}\">#{node.name}</a>"
      if node.children && node.children.size > 0
        retval += print_children(node.children)
      end
      retval += "</li>"
    end
    retval += "</ul>"
    return retval
  end

currently it is giving me what i need:

- Parent 1
-- Child 1
--- Sub Child 1
--- Sub Child 2
-- Child 2
-- Child 3
- Parent 2
-- Child 4
-- Child 5
--- Sub Child 3

so, here are my two questions:

- how can i make this better performing and rubyish?

- as this is looping through every element of @page_list, after i'm done
with the element, i would like to remove it with @page_list.delete(obj) in
get_children method after the line "tmp << obj" however this is causing me
lose data so instead of the above structure i get something like this:

- Parent 1
-- Child 1
--- Sub Child 1
-- Child 2
- Parent 2
-- Child 4

why is this happening?

thanks in advance.

Muhammet S. AYDIN
http://mengu.net
http://compector.com

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