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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;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Text;
using System.Threading;
using System.Xml;
using System.Xml.Schema;
using System.Xml.XPath;
namespace System.Xml.Xsl.Runtime
{
/// <summary>
/// RtfNavigators store Xslt result-tree-fragments. At runtime, the Xslt library tests to see if a Navigator
/// is an RtfNavigator in order to enforce certain restrictions, such as prohibiting querying into Rtfs.
/// Furthermore, Rtfs must store extra serialization information required in order to properly implement the
/// Xslt disable-output-escaping flag.
/// </summary>
internal abstract class RtfNavigator : XPathNavigator
{
//-----------------------------------------------
// RtfNavigator
//-----------------------------------------------
/// <summary>
/// Preserve serialization hints when deep copying.
/// </summary>
public abstract void CopyToWriter(XmlWriter writer);
/// <summary>
/// Discard serialization hints and return a navigator that actually allows navigation.
/// </summary>
public abstract XPathNavigator ToNavigator();
//-----------------------------------------------
// XPathNavigator
//-----------------------------------------------
/// <summary>
/// Get the XPath node type of the current node.
/// </summary>
public override XPathNodeType NodeType
{
get { return XPathNodeType.Root; }
}
/// <summary>
/// Get the local name portion of the current node's name.
/// </summary>
public override string LocalName
{
get { return string.Empty; }
}
/// <summary>
/// Get the namespace portion of the current node's name.
/// </summary>
public override string NamespaceURI
{
get { return string.Empty; }
}
/// <summary>
/// Get the name of the current node.
/// </summary>
public override string Name
{
get { return string.Empty; }
}
/// <summary>
/// Get the prefix portion of the current node's name.
/// </summary>
public override string Prefix
{
get { return string.Empty; }
}
/// <summary>
/// Return true if this is an element which used a shortcut tag in its Xml 1.0 serialized form.
/// </summary>
public override bool IsEmptyElement
{
get { return false; }
}
/// <summary>
/// Return the xml name table which was used to atomize all prefixes, local-names, and
/// namespace uris in the document.
/// </summary>
public override XmlNameTable NameTable
{
get { throw new NotSupportedException(); }
}
/// <summary>
/// Position the navigator on the first attribute of the current node and return true. If no attributes
/// can be found, return false.
/// </summary>
public override bool MoveToFirstAttribute()
{
throw new NotSupportedException();
}
/// <summary>
/// If positioned on an attribute, move to its next sibling attribute. If no attributes can be found,
/// return false.
/// </summary>
public override bool MoveToNextAttribute()
{
throw new NotSupportedException();
}
/// <summary>
/// Position the navigator on the namespace within the specified scope. If no matching namespace
/// can be found, return false.
/// </summary>
public override bool MoveToFirstNamespace(XPathNamespaceScope namespaceScope)
{
throw new NotSupportedException();
}
/// <summary>
/// Position the navigator on the next namespace within the specified scope. If no matching namespace
/// can be found, return false.
/// </summary>
public override bool MoveToNextNamespace(XPathNamespaceScope namespaceScope)
{
throw new NotSupportedException();
}
/// <summary>
/// If the current node is an attribute or namespace (not content), return false. Otherwise,
/// move to the next content node. Return false if there are no more content nodes.
/// </summary>
public override bool MoveToNext()
{
throw new NotSupportedException();
}
/// <summary>
/// If the current node is an attribute or namespace (not content), return false. Otherwise,
/// move to the previous (sibling) content node. Return false if there are no previous content nodes.
/// </summary>
public override bool MoveToPrevious()
{
throw new NotSupportedException();
}
/// <summary>
/// Move to the first content-typed child of the current node. Return false if the current
/// node has no content children.
/// </summary>
public override bool MoveToFirstChild()
{
throw new NotSupportedException();
}
/// <summary>
/// Position the navigator on the parent of the current node. If the current node has no parent,
/// return false.
/// </summary>
public override bool MoveToParent()
{
throw new NotSupportedException();
}
/// <summary>
/// Position to the navigator to the element whose id is equal to the specified "id" string.
/// </summary>
public override bool MoveToId(string id)
{
throw new NotSupportedException();
}
/// <summary>
/// Returns true if this navigator is positioned to the same node as the "other" navigator. Returns false
/// if not, or if the "other" navigator is not the same type as this navigator.
/// </summary>
public override bool IsSamePosition(XPathNavigator other)
{
throw new NotSupportedException();
}
}
/// <summary>
/// This navigator is a cursor over a cache that stores Xslt disable-output-escaping flags.
/// </summary>
internal sealed class RtfTreeNavigator : RtfNavigator
{
private XmlEventCache _events;
private NavigatorConstructor _constr;
private XmlNameTable _nameTable;
//-----------------------------------------------
// Constructors
//-----------------------------------------------
/// <summary>
/// Create a new navigator over the specified cache of Xml events.
/// </summary>
public RtfTreeNavigator(XmlEventCache events, XmlNameTable nameTable)
{
_events = events;
_constr = new NavigatorConstructor();
_nameTable = nameTable;
}
/// <summary>
/// Copy constructor.
/// </summary>
public RtfTreeNavigator(RtfTreeNavigator that)
{
_events = that._events;
_constr = that._constr;
_nameTable = that._nameTable;
}
//-----------------------------------------------
// RtfNavigator
//-----------------------------------------------
/// <summary>
/// Preserve serialization hints when deep copying.
/// </summary>
public override void CopyToWriter(XmlWriter writer)
{
_events.EventsToWriter(writer);
}
/// <summary>
/// Discard serialization hints and return a navigator that actually allows navigation.
/// </summary>
public override XPathNavigator ToNavigator()
{
return _constr.GetNavigator(_events, _nameTable);
}
//-----------------------------------------------
// XPathItem
//-----------------------------------------------
/// <summary>
/// Get the string value of the current node, computed using data model dm:string-value rules.
/// If the node has a typed value, return the string representation of the value. If the node
/// is not a parent type (comment, text, pi, etc.), get its simple text value. Otherwise,
/// concatenate all text node descendants of the current node.
/// </summary>
public override string Value
{
get { return _events.EventsToString(); }
}
//-----------------------------------------------
// XPathNavigator
//-----------------------------------------------
/// <summary>
/// Get the base URI of the Rtf.
/// </summary>
public override string BaseURI
{
get { return _events.BaseUri; }
}
/// <summary>
/// Create a copy of this navigator, positioned to the same node in the tree.
/// </summary>
public override XPathNavigator Clone()
{
return new RtfTreeNavigator(this);
}
/// <summary>
/// Position this navigator to the same position as the "other" navigator. If the "other" navigator
/// is not of the same type as this navigator, then return false.
/// </summary>
public override bool MoveTo(XPathNavigator other)
{
RtfTreeNavigator? that = other as RtfTreeNavigator;
if (that != null)
{
_events = that._events;
_constr = that._constr;
_nameTable = that._nameTable;
return true;
}
return false;
}
}
/// <summary>
/// This RtfNavigator specializes the case of a root node having a single text node child. This is a very common
/// case, such as in <xsl:variable name="foo">bar</xsl:variable>.
/// </summary>
internal sealed class RtfTextNavigator : RtfNavigator
{
private string _text, _baseUri;
private NavigatorConstructor _constr;
//-----------------------------------------------
// Constructors
//-----------------------------------------------
/// <summary>
/// Create a new navigator having a text node with value = "text" string.
/// </summary>
public RtfTextNavigator(string text, string baseUri)
{
_text = text;
_baseUri = baseUri;
_constr = new NavigatorConstructor();
}
/// <summary>
/// Copy constructor.
/// </summary>
public RtfTextNavigator(RtfTextNavigator that)
{
_text = that._text;
_baseUri = that._baseUri;
_constr = that._constr;
}
//-----------------------------------------------
// RtfNavigator
//-----------------------------------------------
/// <summary>
/// Preserve serialization hints when deep copying.
/// </summary>
public override void CopyToWriter(XmlWriter writer)
{
writer.WriteString(Value);
}
/// <summary>
/// Discard serialization hints and return a navigator that actually allows navigation.
/// </summary>
public override XPathNavigator ToNavigator()
{
return _constr.GetNavigator(_text, _baseUri, new NameTable());
}
//-----------------------------------------------
// XPathItem
//-----------------------------------------------
/// <summary>
/// Get the string value of the current node, computed using data model dm:string-value rules.
/// If the node has a typed value, return the string representation of the value. If the node
/// is not a parent type (comment, text, pi, etc.), get its simple text value. Otherwise,
/// concatenate all text node descendants of the current node.
/// </summary>
public override string Value
{
get { return _text; }
}
//-----------------------------------------------
// XPathNavigator
//-----------------------------------------------
/// <summary>
/// Get the base URI of the Rtf.
/// </summary>
public override string BaseURI
{
get { return _baseUri; }
}
/// <summary>
/// Create a copy of this navigator, positioned to the same node in the tree.
/// </summary>
public override XPathNavigator Clone()
{
return new RtfTextNavigator(this);
}
/// <summary>
/// Position this navigator to the same position as the "other" navigator. If the "other" navigator
/// is not of the same type as this navigator, then return false.
/// </summary>
public override bool MoveTo(XPathNavigator other)
{
RtfTextNavigator? that = other as RtfTextNavigator;
if (that != null)
{
_text = that._text;
_baseUri = that._baseUri;
_constr = that._constr;
return true;
}
return false;
}
}
/// <summary>
/// This class creates a document on the first call to GetNavigator(), and returns a Navigator from it. On
/// subsequent calls, Navigators from the same document are returned (no new document is created).
/// </summary>
internal sealed class NavigatorConstructor
{
private object? _cache;
/// <summary>
/// Create a document from the cache of events. If a document has already been created previously, return it.
/// This method is thread-safe, and is always guaranteed to return the exact same document, no matter how many
/// threads have called it concurrently.
/// </summary>
public XPathNavigator GetNavigator(XmlEventCache events, XmlNameTable nameTable)
{
if (_cache == null)
{
// Create XPathDocument from event cache
XPathDocument doc = new XPathDocument(nameTable);
XmlRawWriter writer = doc.LoadFromWriter(XPathDocument.LoadFlags.AtomizeNames | (events.HasRootNode ? XPathDocument.LoadFlags.None : XPathDocument.LoadFlags.Fragment), events.BaseUri);
events.EventsToWriter(writer);
writer.Close();
_cache = doc;
}
return ((XPathDocument)_cache).CreateNavigator();
}
/// <summary>
/// Create a document containing a root node and a single text node child with "text" as its text value.
/// This method is thread-safe, and is always guaranteed to return the exact same document, no matter how many
/// threads have called it concurrently.
/// </summary>
public XPathNavigator GetNavigator(string text, string baseUri, XmlNameTable nameTable)
{
if (_cache == null)
{
// Create XPathDocument
XPathDocument doc = new XPathDocument(nameTable);
XmlRawWriter writer = doc.LoadFromWriter(XPathDocument.LoadFlags.AtomizeNames, baseUri);
writer.WriteString(text);
writer.Close();
_cache = doc;
}
return ((XPathDocument)_cache).CreateNavigator();
}
}
}
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