mcs/class/referencesource/System.Data.SqlXml/System/Xml/Xsl/Runtime/XmlIterators.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="XmlIterators.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 //------------------------------------------------------------------------------
   7 using System;
   8 using System.Xml;
   9 using System.Xml.XPath;
  10 using System.ComponentModel;
  11
  12 namespace System.Xml.Xsl.Runtime {
  13
  14     /// <summary>
  15     /// Iterators that use containment to control a nested iterator return one of the following values from MoveNext().
  16     /// </summary>
  17     [EditorBrowsable(EditorBrowsableState.Never)]
  18     public enum IteratorResult {
  19         NoMoreNodes,                // Iteration is complete; there are no more nodes
  20         NeedInputNode,              // The next node needs to be fetched from the contained iterator before iteration can continue
  21         HaveCurrentNode,            // This iterator's Current property is set to the next node in the iteration
  22     };
  23
  24
  25     /// <summary>
  26     /// Tokenize a string containing IDREF values and deref the values in order to get a list of ID elements.
  27     /// </summary>
  28     [EditorBrowsable(EditorBrowsableState.Never)]
  29     public struct IdIterator {
  30         private XPathNavigator navCurrent;
  31         private string[] idrefs;
  32         private int idx;
  33
  34         public void Create(XPathNavigator context, string value) {
  35             this.navCurrent = XmlQueryRuntime.SyncToNavigator(this.navCurrent, context);
  36             this.idrefs = XmlConvert.SplitString(value);
  37             this.idx = -1;
  38         }
  39
  40         public bool MoveNext() {
  41             do {
  42                 this.idx++;
  43                 if (this.idx >= idrefs.Length)
  44                     return false;
  45             }
  46             while (!this.navCurrent.MoveToId(this.idrefs[this.idx]));
  47
  48             return true;
  49         }
  50
  51         /// <summary>
  52         /// Return the current result navigator.  This is only defined after MoveNext() has returned true.
  53         /// </summary>
  54         public XPathNavigator Current {
  55             get { return this.navCurrent; }
  56         }
  57     }
  58 }