mcs/class/referencesource/System.Xml/System/Xml/XPath/Internal/BaseAxisQuery.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="baseaxisquery.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 //------------------------------------------------------------------------------
   7
   8 namespace MS.Internal.Xml.XPath {
   9     using System;
  10     using System.Xml;
  11     using System.Xml.XPath;
  12     using System.Diagnostics;
  13     using System.Globalization;
  14     using System.Xml.Xsl;
  15     using System.Collections;
  16
  17     internal abstract class BaseAxisQuery : Query {
  18         internal Query qyInput;
  19         bool nameTest;
  20         string name;
  21         string prefix;
  22         string nsUri;
  23         XPathNodeType typeTest;
  24
  25         // these two things are the state of this class
  26         // that need to be reset whenever the context changes.
  27         protected XPathNavigator currentNode;
  28         protected int position;
  29
  30         protected BaseAxisQuery(Query qyInput) {
  31             this.name = string.Empty;
  32             this.prefix = string.Empty;
  33             this.nsUri = string.Empty;
  34             this.qyInput = qyInput;
  35         }
  36         protected BaseAxisQuery(Query qyInput, string name, string prefix, XPathNodeType typeTest) {
  37             Debug.Assert(qyInput != null);
  38             this.qyInput  = qyInput;
  39             this.name     = name;
  40             this.prefix   = prefix;
  41             this.typeTest = typeTest;
  42             this.nameTest = prefix.Length != 0 || name.Length != 0;
  43             this.nsUri    = string.Empty;
  44         }
  45         protected BaseAxisQuery(BaseAxisQuery other) : base(other) {
  46             this.qyInput  = Clone(other.qyInput);
  47             this.name     = other.name;
  48             this.prefix   = other.prefix;
  49             this.nsUri    = other.nsUri;
  50             this.typeTest = other.typeTest;
  51             this.nameTest = other.nameTest;
  52             this.position = other.position;
  53             this.currentNode = other.currentNode;
  54         }
  55
  56         public override void Reset() {
  57             position = 0;
  58             currentNode = null; // After this current will not point to context node from Evaluate() call
  59                                 // But this is ok, becuase there is no public Reset() on XPathNodeIterator
  60             qyInput.Reset();
  61         }
  62
  63         public override void SetXsltContext(XsltContext context) {
  64             Debug.Assert(context != null);
  65             nsUri = context.LookupNamespace(prefix);
  66             qyInput.SetXsltContext(context);
  67         }
  68
  69         protected string        Name      { get { return name;     } }
  70         protected string        Prefix    { get { return prefix;   } }
  71         protected string        Namespace { get { return nsUri;    } }
  72         protected bool          NameTest  { get { return nameTest; } }
  73         protected XPathNodeType TypeTest  { get { return typeTest; } }
  74
  75         public override int CurrentPosition { get { return position; } }
  76         public override XPathNavigator Current { get { return currentNode; } }
  77
  78         public virtual bool matches(XPathNavigator e) {
  79             if (
  80                 TypeTest == e.NodeType ||
  81                 TypeTest == XPathNodeType.All ||
  82                 TypeTest == XPathNodeType.Text && (e.NodeType == XPathNodeType.Whitespace || e.NodeType == XPathNodeType.SignificantWhitespace)
  83             ) {
  84                 if (NameTest) {
  85                     if (name.Equals(e.LocalName) || name.Length == 0) {
  86                         if (nsUri.Equals(e.NamespaceURI)){
  87                             return true;
  88                         }
  89                     }
  90                 } else {
  91                     return true;
  92                 }
  93             }
  94             return false;
  95         }
  96
  97         public override object Evaluate(XPathNodeIterator nodeIterator) {
  98             ResetCount();
  99             Reset();
 100             qyInput.Evaluate(nodeIterator);
 101             AssertQuery(qyInput);
 102             return this;
 103         }
 104
 105         public override double XsltDefaultPriority { get {
 106             if (qyInput.GetType() != typeof(ContextQuery)) {
 107                 return 0.5;   // a/b a[b] id('s')/a
 108             }
 109             Debug.Assert(this is AttributeQuery || this is ChildrenQuery);
 110             if (name.Length != 0) {
 111                 return 0; // p:foo, foo, processing-instruction("foo")
 112             }
 113             if (prefix.Length != 0) {
 114                 return -0.25; // p:*
 115             }
 116             return -0.5; // *, text(), node()
 117         } }
 118
 119         public override XPathResultType StaticType { get { return XPathResultType.NodeSet; } }
 120
 121         public override void PrintQuery(XmlWriter w) {
 122             w.WriteStartElement(this.GetType().Name);
 123             if (NameTest) {
 124                 w.WriteAttributeString("name", Prefix.Length != 0 ? Prefix + ':' + Name : Name);
 125             }
 126             if (TypeTest != XPathNodeType.Element) {
 127                 w.WriteAttributeString("nodeType", TypeTest.ToString());
 128             }
 129             qyInput.PrintQuery(w);
 130             w.WriteEndElement();
 131         }
 132     }
 133 }