Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,90 @@
+//------------------------------------------------------------------------------
+// <copyright file="IfAction.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Xml.Xsl.XsltOld {
+    using Res = System.Xml.Utils.Res;
+    using System;
+    using System.Diagnostics;
+    using System.Xml;
+    using System.Xml.XPath;
+
+    internal class IfAction : ContainerAction {
+        internal enum ConditionType {
+            ConditionIf,
+            ConditionWhen,
+            ConditionOtherwise
+        }
+
+        private ConditionType   type;
+        private int             testKey = Compiler.InvalidQueryKey;
+
+        internal IfAction(ConditionType type) {
+            this.type = type;
+        }
+
+        internal override void Compile(Compiler compiler) {
+            CompileAttributes(compiler);
+            if (this.type != ConditionType.ConditionOtherwise) {
+                CheckRequiredAttribute(compiler, this.testKey != Compiler.InvalidQueryKey, "test");
+            }
+
+            if (compiler.Recurse()) {
+                CompileTemplate(compiler);
+                compiler.ToParent();
+            }
+        }
+
+        internal override bool CompileAttribute(Compiler compiler) {
+            string name   = compiler.Input.LocalName;
+            string value  = compiler.Input.Value;
+            if (Ref.Equal(name, compiler.Atoms.Test)) {
+                if (this.type == ConditionType.ConditionOtherwise) {
+                    return false;
+                }
+                this.testKey = compiler.AddBooleanQuery(value);
+            }
+            else {
+                return false;
+            }
+
+            return true;
+        }
+
+        internal override void Execute(Processor processor, ActionFrame frame) {
+            Debug.Assert(processor != null && frame != null);
+
+            switch (frame.State) {
+            case Initialized:
+                if (this.type == ConditionType.ConditionIf || this.type == ConditionType.ConditionWhen) {
+                    Debug.Assert(this.testKey != Compiler.InvalidQueryKey);
+                    bool value = processor.EvaluateBoolean(frame, this.testKey);
+                    if (value == false) {
+                        frame.Finished();
+                        break;
+                    }
+                }
+
+                processor.PushActionFrame(frame);
+                frame.State = ProcessingChildren;
+                break;                              // Allow children to run
+
+            case ProcessingChildren:
+                if (this.type == ConditionType.ConditionWhen ||this.type == ConditionType.ConditionOtherwise) {
+                    Debug.Assert(frame.Container != null);
+                    frame.Exit();
+                }
+
+                frame.Finished();
+                break;
+
+            default:
+                Debug.Fail("Invalid IfAction execution state");
+        		break;
+            }
+        }
+    }
+}