mcs/class/System.XML/System.Xml/XmlDeclaration.cs

   1 //
   2 // System.Xml.XmlDeclaration
   3 //
   4 // Author:
   5 //      Duncan Mak  (duncan@ximian.com)
   6 //
   7 // (C) Ximian, Inc.
   8
   9 using System;
  10 using System.Xml;
  11 using System.Text.RegularExpressions;
  12
  13 namespace System.Xml
  14 {
  15         public class XmlDeclaration : XmlLinkedNode
  16         {
  17                 string encoding = "UTF-8"; // defaults to UTF-8
  18                 string standalone;
  19                 string version;
  20
  21                 protected internal XmlDeclaration (string version, string encoding,
  22                                                    string standalone, XmlDocument doc)
  23                         : base (doc)
  24                 {
  25                         if (encoding == null)
  26                                 encoding = "";
  27
  28                         if (standalone == null)
  29                                 standalone = "";
  30
  31                         this.version = version;
  32                         this.encoding = encoding;
  33                         this.standalone = standalone;
  34                 }
  35
  36                 public string Encoding  {
  37                         get { return encoding; }
  38                         set { encoding = (value == null) ? String.Empty : value; }
  39                 }
  40
  41                 public override string InnerText {
  42                         get { return Value; }
  43                         set { ParseInput (value); }
  44                 }
  45
  46                 public override string LocalName {
  47                         get { return "xml"; }
  48                 }
  49
  50                 public override string Name {
  51                         get { return "xml"; }
  52                 }
  53
  54                 public override XmlNodeType NodeType {
  55                         get { return XmlNodeType.XmlDeclaration; }
  56                 }
  57
  58                 public string Standalone {
  59                         get { return standalone; }
  60                         set {
  61                                 if(value != null)
  62                                 {
  63                                         if (value.ToUpper() == "YES")
  64                                                 standalone = "yes";
  65                                         if (value.ToUpper() == "NO")
  66                                                 standalone = "no";
  67                                 }
  68                                 else
  69                                         standalone = String.Empty;
  70                         }
  71                 }
  72
  73                 public override string Value {
  74                         get {
  75                                 string formatEncoding = "";
  76                                 string formatStandalone = "";
  77
  78                                 if (encoding != String.Empty)
  79                                         formatEncoding = String.Format (" encoding=\"{0}\"", encoding);
  80
  81                                 if (standalone != String.Empty)
  82                                         formatStandalone = String.Format (" standalone=\"{0}\"", standalone);
  83
  84                                 return String.Format ("version=\"{0}\"{1}{2}", Version, formatEncoding, formatStandalone);
  85                         }
  86                         set { ParseInput (value); }
  87                 }
  88
  89                 public string Version {
  90                         get { return version; }
  91                 }
  92
  93                 public override XmlNode CloneNode (bool deep)
  94                 {
  95                         return new XmlDeclaration (Version, Encoding, standalone, OwnerDocument);
  96                 }
  97
  98                 public override void WriteContentTo (XmlWriter w) {}
  99
 100                 public override void WriteTo (XmlWriter w)
 101                 {
 102                         // This doesn't seem to match up very well with w.WriteStartDocument()
 103                         // so writing out custom here.
 104                         w.WriteRaw (String.Format ("<?xml {0}?>", Value));
 105                 }
 106
 107                 void ParseInput (string input)
 108                 {
 109 //                      Encoding = input.Split (new char [] { ' ' }) [1].Split (new char [] { '=' }) [1];
 110 //                      Standalone = input.Split (new char [] { ' ' }) [2].Split (new char [] { '=' }) [1];
 111                         Match m = XmlDeclRegex.Match(input);
 112                         if(!m.Success)
 113                                 throw new XmlException("illegal XML declaration format.");
 114 //                      Version = m.Result("${ver}");
 115                         Encoding = m.Result("${enc}");
 116                         Standalone = m.Result("${sta}");
 117                 }
 118
 119                 // This regular expression matches XMLDecl of XML specification BNF[23]
 120                 static Regex xmlDeclRegex;
 121                 Regex XmlDeclRegex \r
 122                 {
 123                         get \r
 124                         {
 125                                 if(xmlDeclRegex == null) xmlDeclRegex = new Regex(allMatch, RegexOptions.Compiled);
 126                                 return xmlDeclRegex;
 127                         }
 128                 }
 129
 130                 // This code makes some loss, but you may understand a bit easily.
 131                 const string verMatch = "\\s*version\\s*=\\s*(\\'(?<ver>.*?)\\'|\\\"(?<ver>.*?)\")";
 132                 const string encMatch = "\\s*encoding\\s*=\\s*(\\'(?<enc>.*?)\\'|\\\"(?<enc>.*?)\")";
 133                 const string staMatch = "\\s*standalone\\s*=\\s*(\\'(?<sta>.*?)\\'|\\\"(?<sta>.*?)\")";
 134                 const string allMatch = verMatch + "(" + encMatch + ")?(" + staMatch + ")?";
 135         }
 136 }