Question

I am having trouble trying to combine two models for use with a view. I have created a consolidated model object:

Public Class BusinessFormModel
    Public Property busModel As Business
    Public Property busMetaModel As BusinessMeta

    Public Sub New()
         busModel = New Business
         busMetaModel  = New BusinessMeta
    End Sub

End Class

For my View I have a form with something like:

@ModelType business.BusinessFormModel

@Html.TextBox("business_category", Model.busModel.business_category)
..
@Html.TextBox("business_name", Model.busMetaModel.business_name)
..
@Html.TextBox("business_description", Model.busMetaModel.business_description)

My controller looks like this:

Function ShowForm() As ActionResult
     Dim model As new BusinessFormModel
     model.busModel.PopulateFromId(2)
     model.busMetaModel.PopulateFromId(2)

     Return View(model)
End Function

Function Submit(ByVal model As BusinessFormModel) As String
     model.busModel.UpdateCategory()
     ...
     model.busMetaModel.UpdateBusinessDescription()
     Return "Submitted"
End Function

Basically the ShowForm will populate the object with values from my database based on the id. The id is also a property in this model. Then when the form submits I have functions to update the particular field based on the id. However, seems like when Submit() is called the object that is passed contains Nothing values. I should at least be getting data that was bound to the HTML helper controls, right?

I’m not sure if I am doing this right since when I submit the form, the model object that is passed back to the controller does not contain any data. Am I executing the right statements in the view?

Thanks.

Answer 1

You need to look into ViewModel which will allow you to have multiple models and other business logic in a single view. ViewModel example exercise

Taken as an example. You will have a separate ViewModel class that exposes your model(s) to your view besides your Controller.

ViewModel

Public Class StoreIndexViewModel
    Public Property NumberOfGenres As Integer
    Public Property Genres As List(Of String) 

    Public Property AnotherComplexModel As ComplexModel
End Class

Controller

Public Function Index() As ActionResult
    'Create list of genres
    Dim genres = New List(Of String) From {"Rock", "Jazz", "Country", "Pop", "Disco"}
    'Create your view model
    Dim viewModel = New StoreIndexViewModel With {.NumberOfGenres = genres.Count, .Genres = genres}
    Return View(viewModel) 
End Function

In your View, you can still refer to you Model object the same way but it now contains all the Models and other data that now can be used. Hope this helps.