Question

On a Create ActionMethod, where the objective is to add a Record or Two to a table or multiple tables, which is the best way to have a ViewModel and why ?

First method is to have the whole Entities in the ViewModel, like so:

namespace QuotesWeb.ViewModels
{
    public class CreateQuoteVM
    {
        public Quote quote { get; set; }
        public Author author { get; set; }
    }
}

The other method is to have individual properties of the entities, like so:

namespace QuotesWeb.ViewModels
{
    public class CreateQuoteVM
    {
        public string quoteBody;
        public string quoteTags;
        public string AuthorFirstName;
        public string AuthorLastName;
        // and so on
    }
}

I would greatly appreciate a clarification of which is better and why ?

Thank You.

Answer 1

Properties.

Actually, I would say you should not have any entities in viewmodels. You should have viewmodels that correspond to your entities, but as an entirely different object layer.

Why? Because the state of entities in the database might not always match the properties you want to show a user on a web page. Entities may have special properties that you do not want to expose to users, or the web / presentation layer in general.

Take a look at automapper. It’s great for translating the properties of your entities to properties on your viewmodel layer, without having to DTO everything manually.

Update

Another good reason to use properties is because it makes the HTML render more simply. By having the scalar properties, you can do @Html.EditorFor(m => m.PropName) instead of @Html.EditorFor(m => m.EntityType.PropName). IMO your views should be concerned with the individual fields presented to the user, not the way the entities are structured in the domain.