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//------------------------------------------------------------------------------
// <copyright file="XmlDeclaration.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Xml {
using System.Text;
using System.Diagnostics;
// Represents the xml declaration nodes: <?xml version='1.0' ...?>
public class XmlDeclaration : XmlLinkedNode {
const string YES = "yes";
const string NO = "no";
private string version;
private string encoding;
private string standalone;
protected internal XmlDeclaration( string version, string encoding, string standalone, XmlDocument doc ) : base( doc ) {
if ( !IsValidXmlVersion( version ) )
throw new ArgumentException( Res.GetString( Res.Xdom_Version ) );
if( ( standalone != null ) && ( standalone.Length > 0 ) )
if ( ( standalone != YES ) && ( standalone != NO ) )
throw new ArgumentException( Res.GetString(Res.Xdom_standalone, standalone) );
this.Encoding = encoding;
this.Standalone = standalone;
this.Version = version;
}
// The version attribute for <?xml version= '1.0' ... ?>
public string Version {
get { return this.version; }
internal set { this.version = value; }
}
// Specifies the value of the encoding attribute, as for
// <?xml version= '1.0' encoding= 'UTF-8' ?>
public string Encoding {
get { return this.encoding; }
set { this.encoding = ( (value == null) ? String.Empty : value ); }
}
// Specifies the value of the standalone attribute.
public string Standalone {
get { return this.standalone; }
set {
if ( value == null )
this.standalone = String.Empty;
else if ( value.Length == 0 || value == YES || value == NO )
this.standalone = value;
else
throw new ArgumentException( Res.GetString(Res.Xdom_standalone, value) );
}
}
public override String Value {
get { return InnerText; }
set { InnerText = value; }
}
// Gets or sets the concatenated values of the node and
// all its children.
public override string InnerText {
get {
StringBuilder strb = new StringBuilder("version=\"" + Version + "\"");
if ( Encoding.Length > 0 ) {
strb.Append(" encoding=\"");
strb.Append(Encoding);
strb.Append("\"");
}
if ( Standalone.Length > 0 ) {
strb.Append(" standalone=\"");
strb.Append(Standalone);
strb.Append("\"");
}
return strb.ToString();
}
set {
string tempVersion = null;
string tempEncoding = null;
string tempStandalone = null;
string orgEncoding = this.Encoding;
string orgStandalone = this.Standalone;
string orgVersion = this.Version;
XmlLoader.ParseXmlDeclarationValue( value, out tempVersion, out tempEncoding, out tempStandalone );
try {
if ( tempVersion != null && !IsValidXmlVersion(tempVersion) )
throw new ArgumentException(Res.GetString(Res.Xdom_Version));
Version = tempVersion;
if ( tempEncoding != null )
Encoding = tempEncoding;
if ( tempStandalone != null )
Standalone = tempStandalone;
}
catch {
Encoding = orgEncoding;
Standalone = orgStandalone;
Version = orgVersion;
throw;
}
}
}
//override methods and properties from XmlNode
// Gets the name of the node.
public override String Name {
get {
return "xml";
}
}
// Gets the name of the current node without the namespace prefix.
public override string LocalName {
get { return Name;}
}
// Gets the type of the current node.
public override XmlNodeType NodeType {
get { return XmlNodeType.XmlDeclaration;}
}
// Creates a duplicate of this node.
public override XmlNode CloneNode(bool deep) {
Debug.Assert( OwnerDocument != null );
return OwnerDocument.CreateXmlDeclaration( Version, Encoding, Standalone );
}
// Saves the node to the specified XmlWriter.
public override void WriteTo(XmlWriter w) {
w.WriteProcessingInstruction(Name, InnerText);
}
// Saves all the children of the node to the specified XmlWriter.
public override void WriteContentTo(XmlWriter w) {
// Intentionally do nothing since the node doesn't have children.
}
private bool IsValidXmlVersion(string ver) {
return ver.Length >= 3 && ver[0] == '1' && ver[1] == '.' && XmlCharType.IsOnlyDigits(ver, 2, ver.Length - 2);
}
}
}
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