How to validate errors for items in IQueryable collection?

Question

Let's say I have a class TmpClass, I use this class for returning data from Excel sheet using LinqToExcel ExcelQueryFactory. In this class I need to implement some logic to check data correctness. When I retrieve data from Excel sheet using ExcelQueryFactory it returns ExcelQueryable (which descends from IQueryalbe) There can be validation problems with multiple TmpClass instances - how can I process them in a collections style?

Class for Excel sheet data mapping

public class TmpClass
{
    private string _name;
    public string Name
    {
        set {
            if (string.IsNullOrWhiteSpace(value))
            {
                throw new ArgumentException("Value can not be null/whitespace!");
            }
            _name = value;
        }
    }
}

retrieving data from Excel sheet with LinqToExcel ExcelQueryFactory

..initialize ExcelQueryFactory instance, get column names, set column mapping
//retrieve data    
var dataFromExcel = excel.Worksheet<TmpClass>(...worksheet name).ToList();

When reading Excel sheet rows, for some of them TmpClass.Name setter function will throw ArgumentException - I need a way to process all the Excel sheet rows:

1. do some actions for rows (logging) that had ArgumentException
2. and do some other operations for rows with valid data.

Can I get a collection of invalid items (with exception info perhaps)? Can I get a collection of valid items?

Answer 1

It may be hard to do even if you will iterate items manually.

var enumerator = excel.Worksheet<TmpClass>(...).GetEnumerator();
while (true)
{
    try
    {
        if (!enumerator.MoveNext())
            break;
        // use enumerator.Current some way
    }
    catch
    {
        // you can't use enumerator.Current
    }
}

As the exception occurs when calling MoveNext, it's impossible to know whether there are more items in an enumerable or not. And it's not guaranteed that MoveNext had moved a pointer on element actually.

Therefore, apparently, the easiest way is to create another class like the TmpClass without any business-logic, just to store values, and to use this new class.