mcs/class/referencesource/System.Data.SqlXml/System/Xml/Xsl/XsltOld/IfAction.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="IfAction.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 System.Xml.Xsl.XsltOld {
   9     using Res = System.Xml.Utils.Res;
  10     using System;
  11     using System.Diagnostics;
  12     using System.Xml;
  13     using System.Xml.XPath;
  14
  15     internal class IfAction : ContainerAction {
  16         internal enum ConditionType {
  17             ConditionIf,
  18             ConditionWhen,
  19             ConditionOtherwise
  20         }
  21
  22         private ConditionType   type;
  23         private int             testKey = Compiler.InvalidQueryKey;
  24
  25         internal IfAction(ConditionType type) {
  26             this.type = type;
  27         }
  28
  29         internal override void Compile(Compiler compiler) {
  30             CompileAttributes(compiler);
  31             if (this.type != ConditionType.ConditionOtherwise) {
  32                 CheckRequiredAttribute(compiler, this.testKey != Compiler.InvalidQueryKey, "test");
  33             }
  34
  35             if (compiler.Recurse()) {
  36                 CompileTemplate(compiler);
  37                 compiler.ToParent();
  38             }
  39         }
  40
  41         internal override bool CompileAttribute(Compiler compiler) {
  42             string name   = compiler.Input.LocalName;
  43             string value  = compiler.Input.Value;
  44             if (Ref.Equal(name, compiler.Atoms.Test)) {
  45                 if (this.type == ConditionType.ConditionOtherwise) {
  46                     return false;
  47                 }
  48                 this.testKey = compiler.AddBooleanQuery(value);
  49             }
  50             else {
  51                 return false;
  52             }
  53
  54             return true;
  55         }
  56
  57         internal override void Execute(Processor processor, ActionFrame frame) {
  58             Debug.Assert(processor != null && frame != null);
  59
  60             switch (frame.State) {
  61             case Initialized:
  62                 if (this.type == ConditionType.ConditionIf || this.type == ConditionType.ConditionWhen) {
  63                     Debug.Assert(this.testKey != Compiler.InvalidQueryKey);
  64                     bool value = processor.EvaluateBoolean(frame, this.testKey);
  65                     if (value == false) {
  66                         frame.Finished();
  67                         break;
  68                     }
  69                 }
  70
  71                 processor.PushActionFrame(frame);
  72                 frame.State = ProcessingChildren;
  73                 break;                              // Allow children to run
  74
  75             case ProcessingChildren:
  76                 if (this.type == ConditionType.ConditionWhen ||this.type == ConditionType.ConditionOtherwise) {
  77                     Debug.Assert(frame.Container != null);
  78                     frame.Exit();
  79                 }
  80
  81                 frame.Finished();
  82                 break;
  83
  84             default:
  85                 Debug.Fail("Invalid IfAction execution state");
  86                         break;
  87             }
  88         }
  89     }
  90 }