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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
namespace System.Xml
{
/// <summary>
/// This writer wraps an XmlWriter that was not build using the XmlRawWriter architecture (such as XmlTextWriter or a custom XmlWriter)
/// for use in the XslCompilerTransform. Depending on the Xsl stylesheet output settings (which gets transferred to this writer via the
/// internal properties of XmlWriterSettings) this writer will inserts additional lexical information into the resulting Xml 1.0 document:
///
/// 1. CData sections
/// 2. DocType declaration
/// 3. Standalone attribute
///
/// It also calls WriteStateDocument if standalone="yes" and/or a DocType declaration is written out in order to enforce document conformance
/// checking.
/// </summary>
internal sealed class QueryOutputWriterV1 : XmlWriter
{
private readonly XmlWriter _wrapped;
private bool _inCDataSection;
private readonly Dictionary<XmlQualifiedName, XmlQualifiedName?>? _lookupCDataElems;
private readonly BitStack? _bitsCData;
private readonly XmlQualifiedName? _qnameCData;
private bool _outputDocType, _inAttr;
private readonly string? _systemId, _publicId;
public QueryOutputWriterV1(XmlWriter writer, XmlWriterSettings settings)
{
_wrapped = writer;
_systemId = settings.DocTypeSystem;
_publicId = settings.DocTypePublic;
if (settings.OutputMethod == XmlOutputMethod.Xml)
{
bool documentConformance = false;
// Xml output method shouldn't output doc-type-decl if system ID is not defined (even if public ID is)
// Only check for well-formed document if output method is xml
if (_systemId != null)
{
documentConformance = true;
_outputDocType = true;
}
// Check for well-formed document if standalone="yes" in an auto-generated xml declaration
if (settings.Standalone == XmlStandalone.Yes)
{
documentConformance = true;
}
if (documentConformance)
{
if (settings.Standalone == XmlStandalone.Yes)
{
_wrapped.WriteStartDocument(true);
}
else
{
_wrapped.WriteStartDocument();
}
}
if (settings.CDataSectionElements != null && settings.CDataSectionElements.Count > 0)
{
_bitsCData = new BitStack();
_lookupCDataElems = new Dictionary<XmlQualifiedName, XmlQualifiedName?>();
_qnameCData = new XmlQualifiedName();
// Add each element name to the lookup table
foreach (XmlQualifiedName name in settings.CDataSectionElements)
{
_lookupCDataElems[name] = null;
}
_bitsCData.PushBit(false);
}
}
else if (settings.OutputMethod == XmlOutputMethod.Html)
{
// Html output method should output doc-type-decl if system ID or public ID is defined
if (_systemId != null || _publicId != null)
_outputDocType = true;
}
}
//-----------------------------------------------
// XmlWriter interface
//-----------------------------------------------
public override WriteState WriteState
{
get
{
return _wrapped.WriteState;
}
}
public override void WriteStartDocument()
{
_wrapped.WriteStartDocument();
}
public override void WriteStartDocument(bool standalone)
{
_wrapped.WriteStartDocument(standalone);
}
public override void WriteEndDocument()
{
_wrapped.WriteEndDocument();
}
/// <summary>
/// Suppress this explicit call to WriteDocType if information was provided by XmlWriterSettings.
/// </summary>
public override void WriteDocType(string name, string? pubid, string? sysid, string? subset)
{
if (_publicId == null && _systemId == null)
{
Debug.Assert(!_outputDocType);
_wrapped.WriteDocType(name, pubid, sysid, subset);
}
}
/// <summary>
/// Output doc-type-decl on the first element, and determine whether this element is a
/// CData section element.
/// </summary>
public override void WriteStartElement(string? prefix, string localName, string? ns)
{
EndCDataSection();
// Output doc-type declaration immediately before first element is output
if (_outputDocType)
{
WriteState ws = _wrapped.WriteState;
if (ws == WriteState.Start || ws == WriteState.Prolog)
{
_wrapped.WriteDocType(
string.IsNullOrEmpty(prefix) ? localName : $"{prefix}:{localName}",
_publicId,
_systemId,
null);
}
_outputDocType = false;
}
_wrapped.WriteStartElement(prefix, localName, ns);
if (_lookupCDataElems != null)
{
Debug.Assert(_qnameCData != null);
Debug.Assert(_bitsCData != null);
// Determine whether this element is a CData section element
_qnameCData.Init(localName, ns);
_bitsCData.PushBit(_lookupCDataElems.ContainsKey(_qnameCData));
}
}
public override void WriteEndElement()
{
EndCDataSection();
_wrapped.WriteEndElement();
if (_lookupCDataElems != null)
{
Debug.Assert(_bitsCData != null);
_bitsCData.PopBit();
}
}
public override void WriteFullEndElement()
{
EndCDataSection();
_wrapped.WriteFullEndElement();
if (_lookupCDataElems != null)
{
Debug.Assert(_bitsCData != null);
_bitsCData.PopBit();
}
}
public override void WriteStartAttribute(string? prefix, string localName, string? ns)
{
_inAttr = true;
_wrapped.WriteStartAttribute(prefix, localName, ns);
}
public override void WriteEndAttribute()
{
_inAttr = false;
_wrapped.WriteEndAttribute();
}
public override void WriteCData(string? text)
{
_wrapped.WriteCData(text);
}
public override void WriteComment(string? text)
{
EndCDataSection();
_wrapped.WriteComment(text);
}
public override void WriteProcessingInstruction(string name, string? text)
{
EndCDataSection();
_wrapped.WriteProcessingInstruction(name, text);
}
public override void WriteWhitespace(string? ws)
{
if (!_inAttr && (_inCDataSection || StartCDataSection()))
_wrapped.WriteCData(ws);
else
_wrapped.WriteWhitespace(ws);
}
public override void WriteString(string? text)
{
if (!_inAttr && (_inCDataSection || StartCDataSection()))
_wrapped.WriteCData(text);
else
_wrapped.WriteString(text);
}
public override void WriteChars(char[] buffer, int index, int count)
{
if (!_inAttr && (_inCDataSection || StartCDataSection()))
_wrapped.WriteCData(new string(buffer, index, count));
else
_wrapped.WriteChars(buffer, index, count);
}
public override void WriteBase64(byte[] buffer, int index, int count)
{
if (!_inAttr && !_inCDataSection)
{
StartCDataSection();
}
_wrapped.WriteBase64(buffer, index, count);
}
public override void WriteEntityRef(string name)
{
EndCDataSection();
_wrapped.WriteEntityRef(name);
}
public override void WriteCharEntity(char ch)
{
EndCDataSection();
_wrapped.WriteCharEntity(ch);
}
public override void WriteSurrogateCharEntity(char lowChar, char highChar)
{
EndCDataSection();
_wrapped.WriteSurrogateCharEntity(lowChar, highChar);
}
public override void WriteRaw(char[] buffer, int index, int count)
{
if (!_inAttr && (_inCDataSection || StartCDataSection()))
_wrapped.WriteCData(new string(buffer, index, count));
else
_wrapped.WriteRaw(buffer, index, count);
}
public override void WriteRaw(string data)
{
if (!_inAttr && (_inCDataSection || StartCDataSection()))
_wrapped.WriteCData(data);
else
_wrapped.WriteRaw(data);
}
public override void Close()
{
_wrapped.Close();
}
public override void Flush()
{
_wrapped.Flush();
}
public override string? LookupPrefix(string ns)
{
return _wrapped.LookupPrefix(ns);
}
//-----------------------------------------------
// Helper methods
//-----------------------------------------------
/// <summary>
/// Write CData text if element is a CData element. Return true if text should be written
/// within a CData section.
/// </summary>
private bool StartCDataSection()
{
Debug.Assert(!_inCDataSection);
if (_lookupCDataElems != null && _bitsCData!.PeekBit())
{
_inCDataSection = true;
return true;
}
return false;
}
/// <summary>
/// No longer write CData text.
/// </summary>
private void EndCDataSection()
{
_inCDataSection = false;
}
}
}
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