Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,110 @@
+//------------------------------------------------------------------------------
+// <copyright file="FunctionQuery.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace MS.Internal.Xml.XPath {
+    using System;
+    using System.Xml;
+    using System.Xml.Xsl;
+    using System.Xml.XPath;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Collections.Generic;
+
+    internal sealed class FunctionQuery : ExtensionQuery {
+        private IList<Query> args;
+        private IXsltContextFunction function;
+
+        public FunctionQuery(string prefix, string name, List<Query> args) : base(prefix, name) {
+            this.args = args;
+        }
+        private FunctionQuery(FunctionQuery other) : base(other) {
+            this.function = other.function;
+            Query[] tmp = new Query[other.args.Count]; {                
+                for (int i = 0; i < tmp.Length; i ++) {
+                    tmp[i] = Clone(other.args[i]);
+                }
+                args = tmp;
+            }
+            this.args = tmp;
+        }
+
+        public override void SetXsltContext(XsltContext context) {
+            if (context == null) {
+                throw XPathException.Create(Res.Xp_NoContext);
+            }
+			if (this.xsltContext != context) {
+                xsltContext = context;
+                foreach (Query argument in args) {
+                    argument.SetXsltContext(context);
+                }
+                XPathResultType[] argTypes = new XPathResultType[args.Count];
+                for(int i = 0; i < args.Count; i ++) {
+                    argTypes[i] = args[i].StaticType;
+                }
+                function = xsltContext.ResolveFunction(prefix, name, argTypes);
+                // KB article allows to return null, see http://support.microsoft.com/?kbid=324462#6
+                if (function == null) {
+                    throw XPathException.Create(Res.Xp_UndefFunc, QName);
+                }
+            }
+        }
+
+        public override object Evaluate(XPathNodeIterator nodeIterator) {
+			if (xsltContext == null) {
+				throw XPathException.Create(Res.Xp_NoContext);
+			}
+
+            // calculate arguments:
+            object[] argVals = new object[args.Count];
+            for (int i = 0; i < args.Count; i ++) {
+                argVals[i] = args[i].Evaluate(nodeIterator);
+                if (argVals[i] is XPathNodeIterator) {// ForBack Compat. To protect our queries from users. bug#372077 & 20006123 
+                    argVals[i] = new XPathSelectionIterator(nodeIterator.Current, args[i]);
+                }
+            }
+            try {
+                return ProcessResult(function.Invoke(xsltContext, argVals, nodeIterator.Current));
+            } catch(Exception ex) {
+                throw XPathException.Create(Res.Xp_FunctionFailed, QName, ex);
+            }
+        }
+
+        public override XPathNavigator MatchNode(XPathNavigator navigator) {
+            if (name != "key" && prefix.Length != 0) {
+                throw XPathException.Create(Res.Xp_InvalidPattern);
+            }
+            this.Evaluate(new XPathSingletonIterator(navigator, /*moved:*/true));
+            XPathNavigator nav = null;
+            while ((nav = this.Advance()) != null) {
+                if (nav.IsSamePosition(navigator)) {
+                    return nav;
+                }
+            }
+            return nav;
+        }
+
+        public override XPathResultType StaticType { get {
+            XPathResultType result = function != null ? function.ReturnType : XPathResultType.Any;
+			if (result == XPathResultType.Error) {
+				// In v.1 we confused Error & Any so now for backward compatibility we should allow users to return any of them.
+				result = XPathResultType.Any;
+			}
+            return result;
+        } }
+
+        public override XPathNodeIterator Clone() { return new FunctionQuery(this); }
+
+        public override void PrintQuery(XmlWriter w) {
+            w.WriteStartElement(this.GetType().Name);
+            w.WriteAttributeString("name", prefix.Length != 0 ? prefix + ':' + name : name);
+            foreach(Query arg in this.args) {
+                arg.PrintQuery(w);
+            }
+            w.WriteEndElement();
+        }
+    }
+}