source: branches/RemoveBackwardsCompatibility/HeuristicLab.ExtLibs/HeuristicLab.EPPlus/4.0.3/EPPlus-4.0.3/FormulaParsing/Excel/Functions/IntArgumentParser.cs

/* Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied. 
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 * 
 * Author             Change            Date
 *******************************************************************************
 * Mats Alm                       Added                   2013-12-03
 *******************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using OfficeOpenXml.FormulaParsing.Utilities;
using OfficeOpenXml.FormulaParsing.Exceptions;

namespace OfficeOpenXml.FormulaParsing.Excel.Functions
{
    public class IntArgumentParser : ArgumentParser
    {
        public override object Parse(object obj)
        {
            Require.That(obj).Named("argument").IsNotNull();
            int result;
            if (obj is ExcelDataProvider.IRangeInfo)
            {
                var r = ((ExcelDataProvider.IRangeInfo)obj).FirstOrDefault();
                return r == null ? 0 : Convert.ToInt32(r.ValueDouble);
            }
            var objType = obj.GetType();
            if (objType == typeof(int))
            {
                return (int)obj;
            }
            if (objType == typeof(double) || objType == typeof(decimal))
            {
                return Convert.ToInt32(obj);
            }
            if (!int.TryParse(obj.ToString(), out result))
            {
                throw new ExcelErrorValueException(ExcelErrorValue.Create(eErrorType.Value));
            }
            return result;
        }
    }
}