Question

I am currently stuck in the design of this solution.

The data layer design consists of the following:

• Recipe (parent high level object)
  • Language Detail (name, description by language) (many)
    • Headers (many)
    • Steps (many)
      • Ingredients (many)
      • Quantities (many)
      • Procedures (many)
    • Notes (many)

The challenge that I am having is how to create a data access design that will add/remove the child objects in the database when the object is populated from a WCF SaveRecipe(recipe) method?

This all stems from the management asking us to add a communications layer in our application, right now our UI is coupled to our business layer, and the BL is directly coupled to the DAL, we basically need the injection of WCF between the BL and DAL.

I have read in this thread that using L2S isn’t a good idea over WCF, but since the design isn’t new, we have to use this type of methodology, and then move away from it once we can refactor the heavy amounts of UI work.

Answer 1

If you are trying to send stuff down the line with WCF I suggest you create a model of the data you want to move around your domain. As far as I’ve found you can’t serialize IQueryable objects, but you can create a set of classes that Linq populates and then serialize that. For example:

[DataContract] public class Recipe {      [DataMember]     public string Name { get; set; }      [DataMember]     public string Description { get; set; }      [DataMember]     public List<Ingredient> Ingredients { get; set; }  } 

Then fill that up with

List<Recipe> recipes = (from r in dc.recipe                            select new Recpie {                                Name = r.name,                                Description = r.description,                                Ingredients = (Linq code to make list of ingredients)                            }).ToList(); 

And then sending the list down the line with WCF becomes a piece of cake.