1  require "rexml/child"
   2 
   3  module REXML
   4    # A parent has children, and has methods for accessing them.  The Parent
   5    # class is never encountered except as the superclass for some other
   6    # object.
   7    class Parent < Child
   8      include Enumerable
   9      
  10      # Constructor
  11      # @param parent if supplied, will be set as the parent of this object
  12      def initialize parent=nil
  13        super(parent)
  14        @children = []
  15      end
  16      
  17      def add( object )
  18        #puts "PARENT GOTS #{size} CHILDREN"
  19        object.parent = self
  20        @children << object
  21        #puts "PARENT NOW GOTS #{size} CHILDREN"
  22        object
  23      end
  24      
  25      alias :push :add
  26      alias :<< :push
  27      
  28      def unshift( object )
  29        object.parent = self
  30        @children.unshift object
  31      end
  32      
  33      def delete( object )
  34        found = false
  35        @children.delete_if {|c| c.equal?(object) and found = true }
  36        object.parent = nil if found
  37      end
  38      
  39      def each(&block)
  40        @children.each(&block)
  41      end
  42      
  43      def delete_if( &block )
  44        @children.delete_if(&block)
  45      end
  46      
  47      def delete_at( index )
  48        @children.delete_at index
  49      end
  50      
  51      def each_index( &block )
  52        @children.each_index(&block)
  53      end
  54      
  55      # Fetches a child at a given index
  56      # @param index the Integer index of the child to fetch
  57      def []( index )
  58        @children[index]
  59      end
  60      
  61      alias :each_child :each
  62      
  63      
  64      
  65      # Set an index entry.  See Array.[]=
  66      # @param index the index of the element to set
  67      # @param opt either the object to set, or an Integer length
  68      # @param child if opt is an Integer, this is the child to set
  69      # @return the parent (self)
  70      def []=( *args )
  71        args[-1].parent = self
  72        @children[*args[0..-2]] = args[-1]
  73      end
  74      
  75      # Inserts an child before another child
  76      # @param child1 this is either an xpath or an Element.  If an Element,
  77      # child2 will be inserted before child1 in the child list of the parent.
  78      # If an xpath, child2 will be inserted before the first child to match
  79      # the xpath.
  80      # @param child2 the child to insert
  81      # @return the parent (self)
  82      def insert_before( child1, child2 )
  83        if child1.kind_of? String
  84          child1 = XPath.first( self, child1 )
  85          child1.parent.insert_before child1, child2
  86        else
  87          ind = index(child1)
  88          child2.parent.delete(child2) if child2.parent
  89          @children[ind,0] = child2
  90          child2.parent = self
  91        end
  92        self
  93      end
  94      
  95      # Inserts an child after another child
  96      # @param child1 this is either an xpath or an Element.  If an Element,
  97      # child2 will be inserted after child1 in the child list of the parent.
  98      # If an xpath, child2 will be inserted after the first child to match
  99      # the xpath.
 100      # @param child2 the child to insert
 101      # @return the parent (self)
 102      def insert_after( child1, child2 )
 103        if child1.kind_of? String
 104          child1 = XPath.first( self, child1 )
 105          child1.parent.insert_after child1, child2
 106        else
 107          ind = index(child1)+1
 108          child2.parent.delete(child2) if child2.parent
 109          @children[ind,0] = child2
 110          child2.parent = self
 111        end
 112        self
 113      end
 114      
 115      def to_a
 116        @children.dup
 117      end
 118      
 119      # Fetches the index of a given child
 120      # @param child the child to get the index of
 121      # @return the index of the child, or nil if the object is not a child
 122      # of this parent.
 123      def index( child )
 124        count = -1
 125        @children.find { |i| count += 1 ; i.hash == child.hash }
 126        count
 127      end
 128      
 129      # @return the number of children of this parent
 130      def size
 131        @children.size
 132      end
 133      
 134      alias :length :size
 135      
 136      # Replaces one child with another, making sure the nodelist is correct
 137      # @param to_replace the child to replace (must be a Child)
 138      # @param replacement the child to insert into the nodelist (must be a 
 139      # Child)
 140      def replace_child( to_replace, replacement )
 141        @children.map! {|c| c.equal?( to_replace ) ? replacement : c }
 142        to_replace.parent = nil
 143        replacement.parent = self
 144      end
 145      
 146      # Deeply clones this object.  This creates a complete duplicate of this
 147      # Parent, including all descendants.
 148      def deep_clone
 149        cl = clone()
 150        each do |child|
 151          if child.kind_of? Parent
 152            cl << child.deep_clone
 153          else
 154            cl << child.clone
 155          end
 156        end
 157        cl
 158      end
 159      
 160      alias :children :to_a
 161      
 162      def parent?
 163        true
 164      end
 165    end
 166  end