Question

I’m not sure if there is a difference in these two methods. If so, which would be considered the better practice when submitting more than one object to the View.

1. Having the controller make separate calls to the datalayer for each object model and then wrapping the objects in a model to send to view.

2. Defining a ‘presentation’ model and having the controller call that single model to send to the view.

3. other…?

Answer 1

I’m assuming here that you have a view that presents some information from more than one model, perhaps in a list format. For example, you may have a model of a customer which has a set of contacts, but in your list you want to choose to show some of the customer details along with the name and phone number of the primary contact. What I would typically do in a situation like this is define a specific ‘presentation’ model that consists of just those details that I may want to show in this combined view. It would typically be a read-only model. Using LINQ to SQL I might even define this as a table-valued function (to support search) and associate it with a view that encapsulates the join of the various tables. With both you can add the view-based ‘presentation’ model to your DBML and associate the table-valued function with it as a method on the data context.

I prefer doing this because I believe that it is more efficient in terms of queries to construct the query on the server and simply use it from the code. If you weren’t using the table-valued function for searching, you might be able to construct the query in code and select into a ‘presentation’ class. I would favor an actual class over an anonymous type for ease of use in the view. Getting the properties from an anonymous type in the view would be difficult.