XPathDocument.cs source code in C# .NET

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                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Xml / System / Xml / XPath / XPathDocument.cs / 1 / XPathDocument.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
//-----------------------------------------------------------------------------
 
using System; 
using System.IO;
using System.Xml; 
using System.Xml.Schema;
using System.Collections.Generic;
using MS.Internal.Xml.Cache;
using System.Diagnostics; 
using System.Text;
 
namespace System.Xml.XPath { 

    ///  
    /// XDocument follows the XPath/XQuery data model.  All nodes in the tree reference the document,
    /// and the document references the root node of the tree.  All namespaces are stored out-of-line,
    /// in an Element --> In-Scope-Namespaces map.
    ///  
    public class XPathDocument : IXPathNavigable {
        private XPathNode[] pageText, pageRoot, pageXmlNmsp; 
        private int idxText, idxRoot, idxXmlNmsp; 
        private XmlNameTable nameTable;
        private bool hasLineInfo; 
        private Dictionary mapNmsp;
        private Dictionary idValueMap;

        ///  
        /// Flags that control Load behavior.
        ///  
        internal enum LoadFlags { 
            None = 0,
            AtomizeNames = 1,       // Do not assume that names passed to XPathDocumentBuilder have been pre-atomized, and atomize them 
            Fragment = 2,           // Create a document with no document node
        }

 
        //-----------------------------------------------
        // Creation Methods 
        //----------------------------------------------- 

        ///  
        /// Create a new empty document.
        /// 
        internal XPathDocument() {
            this.nameTable = new NameTable(); 
        }
 
        ///  
        /// Create a new empty document.  All names should be atomized using "nameTable".
        ///  
        internal XPathDocument(XmlNameTable nameTable) {
            if (nameTable == null)
                throw new ArgumentNullException("nameTable");
 
            this.nameTable = nameTable;
        } 
 
        /// 
        /// Create a new document and load the content from the reader. 
        /// 
        public XPathDocument(XmlReader reader) : this(reader, XmlSpace.Default) {
        }
 
        /// 
        /// Create a new document from "reader", with whitespace handling controlled according to "space". 
        ///  
        public XPathDocument(XmlReader reader, XmlSpace space) {
            if (reader == null) 
                throw new ArgumentNullException("reader");

            LoadFromReader(reader, space);
        } 

        ///  
        /// Create a new document and load the content from the text reader. 
        /// 
        public XPathDocument(TextReader textReader) { 
            XmlTextReaderImpl reader = SetupReader(new XmlTextReaderImpl(string.Empty, textReader));

            try {
                LoadFromReader(reader, XmlSpace.Default); 
            }
            finally { 
                reader.Close(); 
            }
        } 

        /// 
        /// Create a new document and load the content from the stream.
        ///  
        public XPathDocument(Stream stream) {
            XmlTextReaderImpl reader = SetupReader(new XmlTextReaderImpl(string.Empty, stream)); 
 
            try {
                LoadFromReader(reader, XmlSpace.Default); 
            }
            finally {
                reader.Close();
            } 
        }
 
        ///  
        /// Create a new document and load the content from the Uri.
        ///  
        public XPathDocument(string uri) : this(uri, XmlSpace.Default) {
        }

        ///  
        /// Create a new document and load the content from the Uri, with whitespace handling controlled according to "space".
        ///  
        public XPathDocument(string uri, XmlSpace space) { 
            XmlTextReaderImpl reader = SetupReader(new XmlTextReaderImpl(uri));
 
            try {
                LoadFromReader(reader, space);
            }
            finally { 
                reader.Close();
            } 
        } 

        ///  
        /// Create a writer that can be used to create nodes in this document.  The root node will be assigned "baseUri", and flags
        /// can be passed to indicate that names should be atomized by the builder and/or a fragment should be created.
        /// 
        internal XmlRawWriter LoadFromWriter(LoadFlags flags, string baseUri) { 
            return new XPathDocumentBuilder(this, null, baseUri, flags);
        } 
 
        /// 
        /// Create a writer that can be used to create nodes in this document.  The root node will be assigned "baseUri", and flags 
        /// can be passed to indicate that names should be atomized by the builder and/or a fragment should be created.
        /// 
        internal void LoadFromReader(XmlReader reader, XmlSpace space) {
            XPathDocumentBuilder builder; 
            IXmlLineInfo lineInfo;
            string xmlnsUri; 
            bool topLevelReader; 
            int initialDepth;
 
            if (reader == null)
                throw new ArgumentNullException("reader");

            // Determine line number provider 
            lineInfo = reader as IXmlLineInfo;
            if (lineInfo == null || !lineInfo.HasLineInfo()) 
                lineInfo = null; 
            this.hasLineInfo = (lineInfo != null);
 
            this.nameTable = reader.NameTable;
            builder = new XPathDocumentBuilder(this, lineInfo, reader.BaseURI, LoadFlags.None);

            try { 
                // Determine whether reader is in initial state
                topLevelReader = (reader.ReadState == ReadState.Initial); 
                initialDepth = reader.Depth; 

                // Get atomized xmlns uri 
                Debug.Assert((object) this.nameTable.Get(string.Empty) == (object) string.Empty, "NameTable must contain atomized string.Empty");
                xmlnsUri = this.nameTable.Get("http://www.w3.org/2000/xmlns/");

                // Read past Initial state; if there are no more events then load is complete 
                if (topLevelReader && !reader.Read())
                    return; 
 
                // Read all events
                do { 
                    // If reader began in intermediate state, return when all siblings have been read
                    if (!topLevelReader && reader.Depth < initialDepth)
                        return;
 
                    switch (reader.NodeType) {
                        case XmlNodeType.Element: { 
                            bool isEmptyElement = reader.IsEmptyElement; 

                            builder.WriteStartElement(reader.Prefix, reader.LocalName, reader.NamespaceURI, reader.BaseURI); 

                            // Add attribute and namespace nodes to element
                            while (reader.MoveToNextAttribute()) {
                                string namespaceUri = reader.NamespaceURI; 

                                if ((object) namespaceUri == (object) xmlnsUri) { 
                                    if (reader.Prefix.Length == 0) { 
                                        // Default namespace declaration "xmlns"
                                        Debug.Assert(reader.LocalName == "xmlns"); 
                                        builder.WriteNamespaceDeclaration(string.Empty, reader.Value);
                                    }
                                    else {
                                        Debug.Assert(reader.Prefix == "xmlns"); 
                                        builder.WriteNamespaceDeclaration(reader.LocalName, reader.Value);
                                    } 
                                } 
                                else {
                                    builder.WriteStartAttribute(reader.Prefix, reader.LocalName, namespaceUri); 
                                    builder.WriteString(reader.Value, TextBlockType.Text);
                                    builder.WriteEndAttribute();
                                }
                            } 

                            if (isEmptyElement) 
                                builder.WriteEndElement(true); 
                            break;
                        } 

                        case XmlNodeType.EndElement:
                            builder.WriteEndElement(false);
                            break; 

                        case XmlNodeType.Text: 
                        case XmlNodeType.CDATA: 
                            builder.WriteString(reader.Value, TextBlockType.Text);
                            break; 

                        case XmlNodeType.SignificantWhitespace:
                            if (reader.XmlSpace == XmlSpace.Preserve)
                                builder.WriteString(reader.Value, TextBlockType.SignificantWhitespace); 
                            else
                                // Significant whitespace without xml:space="preserve" is not significant in XPath/XQuery data model 
                                goto case XmlNodeType.Whitespace; 
                            break;
 
                        case XmlNodeType.Whitespace:
                            Debug.Assert(reader.XmlSpace != XmlSpace.Preserve);

                            // Always filter top-level whitespace 
                            if (space == XmlSpace.Preserve && (!topLevelReader || reader.Depth != 0))
                                builder.WriteString(reader.Value, TextBlockType.Whitespace); 
                            break; 

                        case XmlNodeType.Comment: 
                            builder.WriteComment(reader.Value);
                            break;

                        case XmlNodeType.ProcessingInstruction: 
                            builder.WriteProcessingInstruction(reader.LocalName, reader.Value, reader.BaseURI);
                            break; 
 
                        case XmlNodeType.EntityReference:
                            reader.ResolveEntity(); 
                            break;

                        case XmlNodeType.DocumentType:
                            // Create ID tables 
                            SchemaInfo info = XmlReader.GetDtdSchemaInfo(reader);
                            if (info != null) 
                                builder.CreateIdTables(info); 
                            break;
 
                        case XmlNodeType.EndEntity:
                        case XmlNodeType.None:
                        case XmlNodeType.XmlDeclaration:
                            break; 
                    }
                } 
                while (reader.Read()); 
            }
            finally { 
                builder.Close();
            }
        }
 
        /// 
        /// Create a navigator positioned on the root node of the document. 
        ///  
        public XPathNavigator CreateNavigator() {
            return new XPathDocumentNavigator(this.pageRoot, this.idxRoot, null, 0); 
        }


        //----------------------------------------------- 
        // Document Properties
        //----------------------------------------------- 
 
        /// 
        /// Return the name table used to atomize all name parts (local name, namespace uri, prefix). 
        /// 
        internal XmlNameTable NameTable {
            get { return this.nameTable; }
        } 

        ///  
        /// Return true if line number information is recorded in the cache. 
        /// 
        internal bool HasLineInfo { 
            get { return this.hasLineInfo; }
        }

        ///  
        /// Return the singleton collapsed text node associated with the document.  One physical text node
        /// represents each logical text node in the document that is the only content-typed child of its 
        /// element parent. 
        /// 
        internal int GetCollapsedTextNode(out XPathNode[] pageText) { 
            pageText = this.pageText;
            return this.idxText;
        }
 
        /// 
        /// Set the page and index where the singleton collapsed text node is stored. 
        ///  
        internal void SetCollapsedTextNode(XPathNode[] pageText, int idxText) {
            this.pageText = pageText; 
            this.idxText = idxText;
        }

        ///  
        /// Return the root node of the document.  This may not be a node of type XPathNodeType.Root if this
        /// is a document fragment. 
        ///  
        internal int GetRootNode(out XPathNode[] pageRoot) {
            pageRoot = this.pageRoot; 
            return this.idxRoot;
        }

        ///  
        /// Set the page and index where the root node is stored.
        ///  
        internal void SetRootNode(XPathNode[] pageRoot, int idxRoot) { 
            this.pageRoot = pageRoot;
            this.idxRoot = idxRoot; 
        }

        /// 
        /// Every document has an implicit xmlns:xml namespace node. 
        /// 
        internal int GetXmlNamespaceNode(out XPathNode[] pageXmlNmsp) { 
            pageXmlNmsp = this.pageXmlNmsp; 
            return this.idxXmlNmsp;
        } 

        /// 
        /// Set the page and index where the implicit xmlns:xml node is stored.
        ///  
        internal void SetXmlNamespaceNode(XPathNode[] pageXmlNmsp, int idxXmlNmsp) {
            this.pageXmlNmsp = pageXmlNmsp; 
            this.idxXmlNmsp = idxXmlNmsp; 
        }
 
        /// 
        /// Associate a namespace node with an element.
        /// 
        internal void AddNamespace(XPathNode[] pageElem, int idxElem, XPathNode[] pageNmsp, int idxNmsp) { 
            Debug.Assert(pageElem[idxElem].NodeType == XPathNodeType.Element && pageNmsp[idxNmsp].NodeType == XPathNodeType.Namespace);
 
            if (this.mapNmsp == null) 
                this.mapNmsp = new Dictionary();
 
            this.mapNmsp.Add(new XPathNodeRef(pageElem, idxElem), new XPathNodeRef(pageNmsp, idxNmsp));
        }

        ///  
        /// Lookup the namespace nodes associated with an element.
        ///  
        internal int LookupNamespaces(XPathNode[] pageElem, int idxElem, out XPathNode[] pageNmsp) { 
            XPathNodeRef nodeRef = new XPathNodeRef(pageElem, idxElem);
            Debug.Assert(pageElem[idxElem].NodeType == XPathNodeType.Element); 

            // Check whether this element has any local namespaces
            if (this.mapNmsp == null || !this.mapNmsp.ContainsKey(nodeRef)) {
                pageNmsp = null; 
                return 0;
            } 
 
            // Yes, so return the page and index of the first local namespace node
            nodeRef = this.mapNmsp[nodeRef]; 

            pageNmsp = nodeRef.Page;
            return nodeRef.Index;
        } 

        ///  
        /// Add an element indexed by ID value. 
        /// 
        internal void AddIdElement(string id, XPathNode[] pageElem, int idxElem) { 
            if (this.idValueMap == null)
                this.idValueMap = new Dictionary();

            if (!this.idValueMap.ContainsKey(id)) 
                this.idValueMap.Add(id, new XPathNodeRef(pageElem, idxElem));
        } 
 
        /// 
        /// Lookup the element node associated with the specified ID value. 
        /// 
        internal int LookupIdElement(string id, out XPathNode[] pageElem) {
            XPathNodeRef nodeRef;
 
            if (this.idValueMap == null || !this.idValueMap.ContainsKey(id)) {
                pageElem = null; 
                return 0; 
            }
 
            // Extract page and index from XPathNodeRef
            nodeRef = this.idValueMap[id];
            pageElem = nodeRef.Page;
            return nodeRef.Index; 
        }
 
 
        //-----------------------------------------------
        // Helper Methods 
        //-----------------------------------------------

        /// 
        /// Set properties on the reader so that it is backwards-compatible with V1. 
        /// 
        private XmlTextReaderImpl SetupReader(XmlTextReaderImpl reader) { 
            reader.EntityHandling = EntityHandling.ExpandEntities; 
            reader.XmlValidatingReaderCompatibilityMode = true;
            return reader; 
        }
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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XPathDocument.cs source code in C# .NET

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