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

   1 //------------------------------------------------------------------------------
   2 // <copyright file="DescendantQuery.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
  14     internal abstract class DescendantBaseQuery : BaseAxisQuery {
  15         protected bool matchSelf;
  16         protected bool abbrAxis;
  17
  18         public DescendantBaseQuery(Query qyParent, string Name, string Prefix, XPathNodeType Type, bool matchSelf, bool abbrAxis) : base(qyParent, Name, Prefix, Type)  {
  19             this.matchSelf = matchSelf;
  20             this.abbrAxis  = abbrAxis;
  21         }
  22         public DescendantBaseQuery(DescendantBaseQuery other) : base(other) {
  23             this.matchSelf = other.matchSelf;
  24             this.abbrAxis  = other.abbrAxis;
  25         }
  26
  27         public override XPathNavigator MatchNode(XPathNavigator context) {
  28             if (context != null) {
  29                 if (!abbrAxis) {
  30                     throw XPathException.Create(Res.Xp_InvalidPattern);
  31                 }
  32                 XPathNavigator result = null;
  33                 if (matches(context)) {
  34                     if (matchSelf) {
  35                         if ((result = qyInput.MatchNode(context)) != null) {
  36                             return result;
  37                         }
  38                     }
  39
  40                     XPathNavigator anc = context.Clone();
  41                     while (anc.MoveToParent()) {
  42                         if ((result = qyInput.MatchNode(anc)) != null) {
  43                             return result;
  44                         }
  45                     }
  46                 }
  47             }
  48             return null;
  49         }
  50
  51         public override void PrintQuery(XmlWriter w) {
  52             w.WriteStartElement(this.GetType().Name);
  53             if (matchSelf) {
  54                 w.WriteAttributeString("self", "yes");
  55             }
  56             if (NameTest) {
  57                 w.WriteAttributeString("name", Prefix.Length != 0 ? Prefix + ':' + Name : Name);
  58             }
  59             if (TypeTest != XPathNodeType.Element) {
  60                 w.WriteAttributeString("nodeType", TypeTest.ToString());
  61             }
  62             qyInput.PrintQuery(w);
  63             w.WriteEndElement();
  64         }
  65     }
  66 }