a lot of this is open to interpretation. There are a number of approaches and is down to which ever suits you best. My approach is below if its some help.
Should the View know about the Model to use correct data?
Yes. The view has a model import directive for it to bind to when it's rendered. If the view didn't know anything about the model it was accessing then how could it bind to the data.
Is the Controllers job to fetch data from E.G a database and create a Model from that, and the View should use the Model data for display?
No, the controller should no nothing about the implementation of the data layer. The controllers only job should be to invoke the services that it needs to build up the view model.
What is Model Business Logic? (Please don't use fields to explain)
Not to sure about the exact term "Model Business Logic". Model can be used to describe domain models or in this case View models. Business logic are operations you perform on business or domain model objects populated by some service.
The way how i handle ViewModels and business logic as you say is to separate out the domain model, e.g. Customer or Order in a separate dll and have those domain objects populated by a service. Then your View Model becomes a composite of domain model objects.
So in all.. the controller makes a call out to services that consume datalayers which in term return you populated domain objects. These can then be used to populate your view model which is then used by the view.
I've added below a very simplistic look at approach which will hopefully point you in the right direction.
public class MyController
{
[HttpGet]
public ViewResult GetCustomer(int customerID)
{
var myViewModel = new CustomerViewModel();
var myService = new MyServiceLayer();
var myCustomerDetails = myService.GetCustomerDetails(customerID);
myViewModel.Customer = myCustomerDetails;
return View("CustomerDetails", myViewModel);
}
}
public class CustomerViewModel
{
public CustomerDomainObject Customer { get; set; }
}
public class CustomerDomainObject
{
public string Name {get;set;}
}
public class MyServiceLayer
{
public CustomerDomainObject GetCustomerDetails(int customerID)
{
var myCustomer = new CustomerDomainObject();
var dataLayer = new MyDataLayer();
var myCustomerData = dataLayer.GetCustomerDetails(customerID);
var myDataRow = myCustomerData.Tables[0].Rows[0];
myCustomer.Name = myDataRow["Name"].ToString();
return myCustomer;
}
}
public class MyDataLayer
{
public DataSet GetCustomerDetails(int customerID)
{
//Execute proc etc...
return new DataSet();
}
}
