Question

In the code below I am trying to get the null, empty string, and source components out of a List. I have not tested this code yet but my intuition tells me it will break when filtering the List for source and empty string if it comes by a null value.

I tried to extract the null values first, but I am still filtering the base List. How can I re-write this code to accomplish what I am trying to do in the best way?

List<LineItem> nullList=itemsList.Where(s => s[Constants.ProductSource] == null)
                                 .ToList();

NALineItems = itemsList.Where(s => s[Constants.ProductSource] == source 
                                   || s[Constants.ProductSource] == String.Empty)
                       .ToList();

NALineItems = nullList.Union(NALineItems).ToList(); 

s[Constants.ProductSource] is an attachment property to Microsoft ECommerce PurchaseOrder object. Its basically another property of an object.

Answer 1

Based on “I am trying to get the null, empty string, and source components out of a List” I assume you mean you want a list with these 3 specific values.

var allItems = itemsList
                 .Where(s => string.IsNullOrEmpty(s[Constants.ProductSource])
                             || s[Constants.ProductSource] == source)
                 .ToList()