require "rexml/node"
module REXML
##
# A Child object is something contained by a parent, and this class
# contains methods to support that. Most user code will not use this
# class directly.
class Child
include Node
attr_reader :parent # The Parent of this object
# Constructor. Any inheritors of this class should call super to make
# sure this method is called.
# parent::
# if supplied, the parent of this child will be set to the
# supplied value, and self will be added to the parent
def initialize( parent = nil )
@parent = nil
# Declare @parent, but don't define it. The next line sets the
# parent.
parent.add( self ) if parent
end
# Replaces this object with another object. Basically, calls
# Parent.replace_child
#
# Returns:: self
def replace_with( child )
@parent.replace_child( self, child )
self
end
# Removes this child from the parent.
#
# Returns:: self
def remove
unless @parent.nil?
@parent.delete self
end
self
end
# Sets the parent of this child to the supplied argument.
#
# other::
# Must be a Parent object. If this object is the same object as the
# existing parent of this child, no action is taken. Otherwise, this
# child is removed from the current parent (if one exists), and is added
# to the new parent.
# Returns:: The parent added
def parent=( other )
return @parent if @parent == other
@parent.delete self if defined? @parent and @parent
@parent = other
end
alias :next_sibling :next_sibling_node
alias :previous_sibling :previous_sibling_node
# Sets the next sibling of this child. This can be used to insert a child
# after some other child.
# a = Element.new("a")
# b = a.add_element("b")
# c = Element.new("c")
# b.next_sibling = c
# # => <a><b/><c/></a>
def next_sibling=( other )
parent.insert_after self, other
end
# Sets the previous sibling of this child. This can be used to insert a
# child before some other child.
# a = Element.new("a")
# b = a.add_element("b")
# c = Element.new("c")
# b.previous_sibling = c
# # => <a><b/><c/></a>
def previous_sibling=(other)
parent.insert_before self, other
end
# Returns:: the document this child belongs to, or nil if this child
# belongs to no document
def document
return parent.document unless parent.nil?
nil
end
# This doesn't yet handle encodings
def bytes
document.encoding
to_s
end
end
end
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