Contents

require "mpt_tree/engine"

module MptTree
  
  def acts_as_tree
    has_one :mpt_tree_node, :as=>:tree, :dependent=>:destroy, :class_name=>"MptTree::Node"
    default_scope lambda {joins(:mpt_tree_node).order('mpt_tree_nodes.lft')}

    class_eval do 
      def make_it_root
        create_mpt_tree_node #unless MptTree::Node.root_created? self.class.name
        self.reload
      end

      def tree
        node_ids = mpt_tree_node.tree
        self.class.name.constantize.where(:id => node_ids)
      end

      def insert(node)
        raise "can not be inserted! node already have parent." if node.mpt_tree_node
        mpt_tree_node.insert(node)
      end

      def parent
        ancestors.last
      end
      
      def siblings
        parent.nodes_at_level(level(parent)) - [self]
      end

      def children
        nodes_at_level(1)
      end
      
      def self.root
        name.constantize.first
      end

      def root?
         (level(self.class.name.constantize.first) == 0) ? true : false
      end

      def leaf?
        !children.present?
      end

      def ancestors
        node_ids = mpt_tree_node.ancestors
        self.class.name.constantize.where(:id => node_ids)
      end

      def self_with_ancestors
        ancestors << self
      end

      def level(parent=nil)
        mpt_tree_node.level(parent)
      end

      def nodes_at_level(level)
        nodes = Array.new
        tree.each do |node|
          nodes << node if node.level(self) == level
        end
        nodes
      end

      def change_parent(node)
        mpt_tree_node.destroy
        self.reload
        node.insert(self)
      end

      alias_method :<<, :insert
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
mpt_tree-0.0.7	lib/mpt_tree.rb