/source/library/Interlace/Binding/ViewConverters/StringIsNullOrEmptyConverter.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

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//       derived from this software without specific prior written permission.

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using System;

using System.Collections.Generic;

using System.Text;



using Interlace.Binding.Views;



#endregion



namespace Interlace.Binding.ViewConverters

{

    public class StringIsNullOrEmptyConverter : ViewConverterBase

    {

        bool _negate;



        public StringIsNullOrEmptyConverter(bool negate)

        {

            _negate = negate;

        }



        public override object ModelToView(object obj)

        {

            return string.IsNullOrEmpty(obj as string) ^ _negate;

        }



        public override object ViewToModel(object obj)

        {

            throw new InvalidOperationException("A change was made to the view that had an " +

                "attached StringIsNullOrEmptyConverter, which is read only.");

        }

    }

}