Initial revision

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@3925 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 165 insertions, 0 deletions

diff --git a/lib/rexml/parent.rb b/lib/rexml/parent.rb
new file mode 100644
index 0000000000..5c1ed97324
--- /dev/null
+++ b/lib/rexml/parent.rb
@@ -0,0 +1,165 @@
+require "rexml/child"
+
+module REXML
+	# A parent has children, and has methods for accessing them.  The Parent
+  # class is never encountered except as the superclass for some other
+  # object.
+	class Parent < Child
+		include Enumerable
+
+		# Constructor
+		# @param parent if supplied, will be set as the parent of this object
+		def initialize parent=nil
+			super(parent)
+			@children = []
+		end
+
+		def add( object )
+			#puts "PARENT GOTS #{size} CHILDREN"
+			object.parent = self
+			@children << object
+			#puts "PARENT NOW GOTS #{size} CHILDREN"
+			object
+		end
+
+		alias :push :add
+		alias :<< :push
+
+		def unshift( object )
+			object.parent = self
+			@children.unshift object
+		end
+
+		def delete( object )
+			return unless @children.include? object
+			@children.delete object
+			object.parent = nil
+		end
+
+		def each(&block)
+			@children.each(&block)
+		end
+
+		def delete_if( &block )
+			@children.delete_if(&block)
+		end
+
+		def delete_at( index )
+			@children.delete_at index
+		end
+
+		def each_index( &block )
+			@children.each_index(&block)
+		end
+
+		# Fetches a child at a given index
+		# @param index the Integer index of the child to fetch
+		def []( index )
+			@children[index]
+		end
+
+		alias :each_child :each
+
+
+
+		# Set an index entry.  See Array.[]=
+		# @param index the index of the element to set
+		# @param opt either the object to set, or an Integer length
+		# @param child if opt is an Integer, this is the child to set
+		# @return the parent (self)
+		def []=( *args )
+			args[-1].parent = self
+			@children[*args[0..-2]] = args[-1]
+		end
+
+		# Inserts an child before another child
+		# @param child1 this is either an xpath or an Element.  If an Element,
+		# child2 will be inserted before child1 in the child list of the parent.
+		# If an xpath, child2 will be inserted before the first child to match
+		# the xpath.
+		# @param child2 the child to insert
+		# @return the parent (self)
+		def insert_before( child1, child2 )
+			if child1.kind_of? String
+				child1 = XPath.first( self, child1 )
+				child1.parent.insert_before child1, child2
+			else
+				ind = index(child1)
+				child2.parent.delete(child2) if child2.parent
+				@children[ind,0] = child2
+				child2.parent = self
+			end
+			self
+		end
+
+		# Inserts an child after another child
+		# @param child1 this is either an xpath or an Element.  If an Element,
+		# child2 will be inserted after child1 in the child list of the parent.
+		# If an xpath, child2 will be inserted after the first child to match
+		# the xpath.
+		# @param child2 the child to insert
+		# @return the parent (self)
+		def insert_after( child1, child2 )
+			if child1.kind_of? String
+				child1 = XPath.first( self, child1 )
+				child1.parent.insert_after child1, child2
+			else
+				ind = index(child1)+1
+				child2.parent.delete(child2) if child2.parent
+				@children[ind,0] = child2
+				child2.parent = self
+			end
+			self
+		end
+
+		def to_a
+			@children.dup
+		end
+
+		# Fetches the index of a given child
+		# @param child the child to get the index of
+		# @return the index of the child, or nil if the object is not a child
+		# of this parent.
+		def index( child )
+			count = -1
+			@children.find { |i| count += 1 ; i.hash == child.hash }
+			count
+		end
+
+		# @return the number of children of this parent
+		def size
+			@children.size
+		end
+
+		# Replaces one child with another, making sure the nodelist is correct
+		# @param to_replace the child to replace (must be a Child)
+		# @param replacement the child to insert into the nodelist (must be a 
+		# Child)
+		def replace_child( to_replace, replacement )
+			ind = @children.index( to_replace )
+			to_replace.parent = nil
+			@children[ind,0] = replacement
+			replacement.parent = self
+		end
+
+		# Deeply clones this object.  This creates a complete duplicate of this
+		# Parent, including all descendants.
+		def deep_clone
+			cl = clone()
+			each do |child|
+				if child.kind_of? Parent
+					cl << child.deep_clone
+				else
+					cl << child.clone
+				end
+			end
+			cl
+		end
+
+		alias :children :to_a
+
+		def parent?
+			true
+		end
+	end
+end