NodeFunctions.cs

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using System.Xml.XPath;
using System.Xml.Xsl;
 
namespace MS.Internal.Xml.XPath;
 
internal sealed class NodeFunctions : ValueQuery
{
    private readonly Query _arg;
 
    private readonly Function.FunctionType _funcType;
 
    private XsltContext _xsltContext;
 
    public override XPathResultType StaticType => Function.ReturnTypes[(int)_funcType];
 
    public NodeFunctions(Function.FunctionType funcType, Query arg)
    {
        _funcType = funcType;
        _arg = arg;
    }
 
    public override void SetXsltContext(XsltContext context)
    {
        _xsltContext = (context.Whitespace ? context : null);
        if (_arg != null)
        {
            _arg.SetXsltContext(context);
        }
    }
 
    private XPathNavigator EvaluateArg(XPathNodeIterator context)
    {
        if (_arg == null)
        {
            return context.Current;
        }
        _arg.Evaluate(context);
        return _arg.Advance();
    }
 
    public override object Evaluate(XPathNodeIterator context)
    {
        switch (_funcType)
        {
        case Function.FunctionType.FuncPosition:
            return (double)context.CurrentPosition;
        case Function.FunctionType.FuncLast:
            return (double)context.Count;
        case Function.FunctionType.FuncNameSpaceUri:
        {
            XPathNavigator xPathNavigator2 = EvaluateArg(context);
            if (xPathNavigator2 != null)
            {
                return xPathNavigator2.NamespaceURI;
            }
            break;
        }
        case Function.FunctionType.FuncLocalName:
        {
            XPathNavigator xPathNavigator2 = EvaluateArg(context);
            if (xPathNavigator2 != null)
            {
                return xPathNavigator2.LocalName;
            }
            break;
        }
        case Function.FunctionType.FuncName:
        {
            XPathNavigator xPathNavigator2 = EvaluateArg(context);
            if (xPathNavigator2 != null)
            {
                return xPathNavigator2.Name;
            }
            break;
        }
        case Function.FunctionType.FuncCount:
        {
            _arg.Evaluate(context);
            int num = 0;
            if (_xsltContext != null)
            {
                XPathNavigator xPathNavigator;
                while ((xPathNavigator = _arg.Advance()) != null)
                {
                    if (xPathNavigator.NodeType != XPathNodeType.Whitespace || _xsltContext.PreserveWhitespace(xPathNavigator))
                    {
                        num++;
                    }
                }
            }
            else
            {
                while (_arg.Advance() != null)
                {
                    num++;
                }
            }
            return (double)num;
        }
        }
        return string.Empty;
    }
 
    public override XPathNodeIterator Clone()
    {
        NodeFunctions nodeFunctions = new NodeFunctions(_funcType, Query.Clone(_arg));
        nodeFunctions._xsltContext = _xsltContext;
        return nodeFunctions;
    }
}