Script Engine Implemented by C# and Regular Expression

using System;
using System.Collections.Generic;
using System.Data;
using System.Text;

namespace Zadesoft.Library.Script.ExternalValueProviders
{
    public class DataRowExternalValueProvider
        : IExternalValueProvider
    {
        private DataRow _row = null;

        public DataRowExternalValueProvider()
        {
        }

        public DataRowExternalValueProvider(DataRow row)
        {
            ResetDataRow(row);
        }

        public void ResetDataRow(DataRow row)
        {
            if (row == null)
            {
                throw new ArgumentNullException("source data row is null");
            }

            if (row.Table == null)
            {
                throw new ArgumentException("source data row has got no table");
            }

            _row = row;
        }

        #region IAvailableValueProvider Members

        public string Name
        {
            get { return "DataRow"; }
        }

        public bool Contains(string name)
        {
            if (_row == null)
            {
                return false;
            }

            lock (_row)
            {
                return _row.Table.Columns.Contains(name);
            }
        }

        public object GetAvailable(string name)
        {
            if (_row == null || string.IsNullOrEmpty(name))
            {
                throw new ArgumentException("available name is invalid");
            }

            lock (_row)
            {
                if (!_row.Table.Columns.Contains(name))
                {
                    throw new AvailableNotFoundInProviderException(this, name);
                }

                return _row[name];
            }
        }

        public void SetAvailable(string name, object value)
        {
            if (_row == null || string.IsNullOrEmpty(name))
            {
                throw new ArgumentException("available name is invalid");
            }

            lock (_row)
            {
                if (!_row.Table.Columns.Contains(name))
                {
                    throw new AvailableNotFoundInProviderException(this, name);
                }

                _row[name] = value;
            }
        }

        #endregion
    }
}