FunctionQuery.cs source code in C# .NET

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Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Xml / System / Xml / XPath / Internal / FunctionQuery.cs / 1 / FunctionQuery.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
//-----------------------------------------------------------------------------
 
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 args;
        private IXsltContextFunction function; 

        public FunctionQuery(string prefix, string name, List 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(); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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