MVC, as its name suggests, has a Model, a View, and Controller. To create a form, you set up a class that will act as your Model, containing the properties that need to be worked with in a particular view. This is a different thing than your entity, the class that corresponds to a table in your database. You can sometimes use the entity as the Model, but especially in the case of a multi-step form, you don't want to persist the data until the end, which means, they'll need to be separate.
This brings us to the topic of view models, which is actually from another different pattern called MVVM. Regardless, your Model for these views will be a series of view models that contain just the information that the particular step needs to collect. At the end, you will piece all of the collected data together by creating an instance of your entity and mapping the property values from each view model over to it. Then, you will save the entity.
Now, as far as persisting the collected data between requests goes, that's where your session comes in. You'll merely add each posted view model into your Session
object, and then at the end, fetch all of them from the Session
object to create your entity.
So each POST action will have something like the following:
[HttpPost]
public ActionResult Step1(Step1ViewModel model)
{
if (ModelState.IsValid)
{
Session["Step1"] = model;
return RedirectToAction("Step2");
}
// errors
return View(model);
}
Then, your final POST action:
[HttpPost]
public ActionResult StepFinal(StepFinalViewModel)
{
if (ModelState.IsValid)
{
var myEntity = new MyEntity();
var step1 = Session['Step1'] as Step1ViewModel;
myEntity.SomeField = step1.SomeField;
// ... repeat for field in view model, then for each step
db.MyEntities.Add(myEntity);
db.SaveChanges();
Session.Remove('Step1');
// repeat for each step in session
return RedirectToAction("Success");
}
// errors
return View(model);
}