1  require 'rexml/encoding'
   2  require 'rexml/source'
   3 
   4  module REXML
   5    # NEEDS DOCUMENTATION
   6    class XMLDecl < Child
   7      include Encoding
   8 
   9      DEFAULT_VERSION = "1.0";
  10      DEFAULT_ENCODING = "UTF-8";
  11      DEFAULT_STANDALONE = "no";
  12      START = '<\?xml';
  13      STOP = '\?>';
  14 
  15      attr_accessor :version, :standalone
  16      attr_reader :writeencoding, :writethis
  17 
  18      def initialize(version=DEFAULT_VERSION, encoding=nil, standalone=nil)
  19        @writethis = true
  20        @writeencoding = !encoding.nil?
  21        if version.kind_of? XMLDecl
  22          super()
  23          @version = version.version
  24          self.encoding = version.encoding
  25          @writeencoding = version.writeencoding
  26          @standalone = version.standalone
  27        else
  28          super()
  29          @version = version
  30          self.encoding = encoding
  31          @standalone = standalone
  32        end
  33        @version = DEFAULT_VERSION if @version.nil?
  34      end
  35 
  36      def clone
  37        XMLDecl.new(self)
  38      end
  39 
  40      # indent::
  41      #   Ignored.  There must be no whitespace before an XML declaration
  42      # transitive::
  43      #   Ignored
  44      # ie_hack::
  45      #   Ignored
  46      def write(writer, indent=-1, transitive=false, ie_hack=false)
  47        return nil unless @writethis or writer.kind_of? Output
  48        writer << START.sub(/\\/u, '')
  49        if writer.kind_of? Output
  50          writer << " #{content writer.encoding}"
  51        else
  52          writer << " #{content encoding}"
  53        end
  54        writer << STOP.sub(/\\/u, '')
  55      end
  56 
  57      def ==( other )
  58        other.kind_of?(XMLDecl) and
  59        other.version == @version and
  60        other.encoding == self.encoding and
  61        other.standalone == @standalone
  62      end
  63 
  64      def xmldecl version, encoding, standalone
  65        @version = version
  66        self.encoding = encoding
  67        @standalone = standalone
  68      end
  69 
  70      def node_type
  71        :xmldecl
  72      end
  73 
  74      alias :stand_alone? :standalone
  75      alias :old_enc= :encoding=
  76 
  77      def encoding=( enc )
  78        if enc.nil?
  79          self.old_enc = "UTF-8"
  80          @writeencoding = false
  81        else
  82          self.old_enc = enc
  83          @writeencoding = true
  84        end
  85        self.dowrite
  86      end
  87 
  88      # Only use this if you do not want the XML declaration to be written;
  89      # this object is ignored by the XML writer.  Otherwise, instantiate your
  90      # own XMLDecl and add it to the document.
  91      #
  92      # Note that XML 1.1 documents *must* include an XML declaration
  93      def XMLDecl.default
  94        rv = XMLDecl.new( "1.0" )
  95        rv.nowrite
  96        rv
  97      end
  98 
  99      def nowrite
 100        @writethis = false
 101      end
 102 
 103      def dowrite
 104        @writethis = true
 105      end
 106 
 107      def inspect
 108        START.sub(/\\/u, '') + " ... " + STOP.sub(/\\/u, '')
 109      end
 110 
 111      private
 112      def content(enc)
 113        rv = "version='#@version'"
 114        rv << " encoding='#{enc}'" if @writeencoding || enc !~ /utf-8/i
 115        rv << " standalone='#@standalone'" if @standalone
 116        rv
 117      end
 118    end
 119  end