Soft deletes and LINQ

I prefer either of the following:

• 1.      Two properties: one for all and one for active books
• 2.      A property that returns only active books; a method (“GetAllBooks()”) that returns everything. 

#2 is cleanest but you can’t bind to a method … which is why I usually end up with #1.  

Think about what Author.Books should return in the usual case.  Should it (a) return all books or (b) return active books. 

DevForce by default generates a “Books” property for the (a) interpretation.  Most people want the “Books” property to behave like (b). Therefore, I would: 

1. ·        Rename (in the EDM) the “Books” navigation property to “AllBooks” (or some such convention)
2. ·        Add a custom “Books” property to the Author partial class that returns only active books. 

One possible implementation of that custom property is: 

 public partial class // extends the generated Author class
 {
     /// <summary>Gets the Author’s active Books (books that are not deleted).</summary>
     [Bindable(false)]
     [Display(Name = "Books", AutoGenerateField = false)]
     public RelatedEntityList<Book> Books
     {
         get { return new RelatedEntityList<Book>(
                  this.Books.Where(b=>b.Active == true),
                  PropertyMetadata.Books.GetEntityReference(this)
                  ); }
     }
 }

It is no accident that this looks very similar to the code that DevForce generated for Author.AllBooks. 

It is not the only possible implementation. RelatedEntityList<T> is a DevForce internal class … one that, in general, you should not create yourself. The advantage is that this is a “live” list; if you toggle a Book between active and deleted, this list updates automatically (adding or removing a Book automatically).