/// <summary>
/// Private method handles parsing filter from string based on inputs
/// </summary>
/// <param name="filterString">full filter string</param>
/// <param name="workingString">working string pared down from filter string</param>
/// <param name="opVal">operator value - equals or not equals</param>
/// <returns></returns>
private static Filter parseFilterFromString(string workingString, FilterOperator filterOp)
{
Filter retVal = null;
string opVal = getOpSign(filterOp);
workingString = workingString.Replace(opVal, "Þ");
string[] filterTestSplit = workingString.Split('Þ');
if (filterTestSplit.Length == 2)
{
retVal = new Filter(filterTestSplit[0], filterOp, filterTestSplit[1]);
}
else if (filterTestSplit.Length > 2)
{
throw new ArgumentException("Cannot parse filter'" + workingString + "'. There are too many " + opVal + " symbols");
}
return retVal;
}