Question

For my management application, i have in my modelfolder a dbml file with entities (ex. person, company, address, contact, …)

With help of mvc i can handle all CRUD operations so far, but only from 1 entity.
Now I want to show in 1 view information of the person entity and also the corresponding information of contact and address entity. The entities are already connected with the correct relations.

How can I do this efficiently ?

Answer 1

You need to create a ViewModel that will be used to hold information from each entity you need within your actual View.

For example, I have a controller called PublicationsController that will build a catalog page within my web application. One ActionResult needs to provide a ViewModel called PublicationsListViewModel to my View.

PublicationsListViewModel:

public class PublicationsListViewModel
{
    public IList<Publication> Publications { get; set; }

    public PagingInfo PagingInfo { get; set; }

    public String CurrentCategory { get; set; }

    public Dictionary<String, String> SelectedItems { get; set; }
}

As you can see, the PublicationsListViewModel is just a container for each Entity that needs to be passed to my View.

My PublicationsController looks like this:

Controller:

public ActionResult List(Cart cart, string category, int page = 1)
{
    Dictionary<String, String> selectedItems = new Dictionary<String, String>();

    foreach (var line in cart.Lines)
    {
        selectedItems.Add(line.Publication.PDFID.ToString(), line.Quantity.ToString());
    }

    foreach (var line in cart.Lines)
    {
        ViewData.Add(line.Publication.PDFID.ToString(), line.Quantity.ToString());
    }

    var publicationsToShow = (category == null)
                    ? publicationsRepository.Publications
                    : publicationsRepository.Publications.Where(x => x.Category.Equals(category, StringComparison.CurrentCultureIgnoreCase));

    var viewModel = new PublicationsListViewModel
    {
        Publications = publicationsToShow.Skip((page - 1) * PageSize).Take(PageSize).ToList(),
        PagingInfo = new PagingInfo
        {
            CurrentPage = page,
            ItemsPerPage = PageSize,
            TotalItems = publicationsToShow.Count()
        },
        CurrentCategory = category,
        SelectedItems = selectedItems
    };

    return View(viewModel); // Passed to view as ViewData.Model (or simply Model)
}

And my View looks like this

View:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<myNameSpace.WebUI.Models.PublicationsListViewModel>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Publications : <%: Model.CurrentCategory ?? "All Publications" %>
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <% 
    foreach (var publication in Model.Publications)
    { 
       Html.RenderPartial("PublicationSummary", publication, ViewData); 
    } 
    %>
    <div class="pager">
        <%: Html.PageLinks(Model.PagingInfo, x => Url.Action("List", new { page = x, category = Model.CurrentCategory }))%>
    </div>
</asp:Content>