lib/rexml/xmldecl.rb

   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