ExtensionQuery.cs

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using System;
using System.Xml.XPath;
using System.Xml.Xsl;
 
namespace MS.Internal.Xml.XPath;
 
internal abstract class ExtensionQuery : Query
{
    protected string prefix;
 
    protected string name;
 
    protected XsltContext xsltContext;
 
    private ResetableIterator _queryIterator;
 
    public override XPathNavigator Current
    {
        get
        {
            if (_queryIterator == null)
            {
                throw XPathException.Create(System.SR.Xp_NodeSetExpected);
            }
            if (_queryIterator.CurrentPosition == 0)
            {
                Advance();
            }
            return _queryIterator.Current;
        }
    }
 
    public override int CurrentPosition
    {
        get
        {
            if (_queryIterator != null)
            {
                return _queryIterator.CurrentPosition;
            }
            return 0;
        }
    }
 
    protected string QName
    {
        get
        {
            if (prefix.Length == 0)
            {
                return name;
            }
            return prefix + ":" + name;
        }
    }
 
    public override int Count
    {
        get
        {
            if (_queryIterator != null)
            {
                return _queryIterator.Count;
            }
            return 1;
        }
    }
 
    public override XPathResultType StaticType => XPathResultType.Any;
 
    public ExtensionQuery(string prefix, string name)
    {
        this.prefix = prefix;
        this.name = name;
    }
 
    protected ExtensionQuery(ExtensionQuery other)
        : base(other)
    {
        prefix = other.prefix;
        name = other.name;
        xsltContext = other.xsltContext;
        _queryIterator = (ResetableIterator)Query.Clone(other._queryIterator);
    }
 
    public override void Reset()
    {
        if (_queryIterator != null)
        {
            _queryIterator.Reset();
        }
    }
 
    public override XPathNavigator Advance()
    {
        if (_queryIterator == null)
        {
            throw XPathException.Create(System.SR.Xp_NodeSetExpected);
        }
        if (_queryIterator.MoveNext())
        {
            return _queryIterator.Current;
        }
        return null;
    }
 
    protected object ProcessResult(object value)
    {
        if (value is string)
        {
            return value;
        }
        if (value is double)
        {
            return value;
        }
        if (value is bool)
        {
            return value;
        }
        if (value is XPathNavigator)
        {
            return value;
        }
        if (value is int)
        {
            return (double)(int)value;
        }
        if (value == null)
        {
            _queryIterator = XPathEmptyIterator.Instance;
            return this;
        }
        if (value is ResetableIterator resetableIterator)
        {
            _queryIterator = (ResetableIterator)resetableIterator.Clone();
            return this;
        }
        if (value is XPathNodeIterator nodeIterator)
        {
            _queryIterator = new XPathArrayIterator(nodeIterator);
            return this;
        }
        if (value is IXPathNavigable iXPathNavigable)
        {
            return iXPathNavigable.CreateNavigator();
        }
        if (value is short)
        {
            return (double)(short)value;
        }
        if (value is long)
        {
            return (double)(long)value;
        }
        if (value is uint)
        {
            return (double)(uint)value;
        }
        if (value is ushort)
        {
            return (double)(int)(ushort)value;
        }
        if (value is ulong)
        {
            return (double)(ulong)value;
        }
        if (value is float)
        {
            return (double)(float)value;
        }
        if (value is decimal)
        {
            return (double)(decimal)value;
        }
        return value.ToString();
    }
}