MVC: pass parameter to view?

Question

MVC newbie question:

I'm picking up a URL of the form go/{mainnav}/{subnav}, which I've successfully routed to the GoController class, method:

public ActionResult Index(string mainnav, string subnav) {
  return View();
}

So far, so good. But now I want the view to return different HTML, depending on the values of mainnav or subnav. Specifically, inside a javascript block, I want to include the line:

myobj.mainnav = [value of mainnav parameter];

and, only if subnav is not null or empty:

myobj.subnav = [value of subnav parameter];

How do you pass those parameters to an aspx page that doesn't have a codebehind?

Answer 1

You use a ViewModel class to transfer the data:

public class IndexViewModel
{
    public string MainNav { get; set; }
    public string SubNav { get; set; }

    public IndexViewModel(string mainnav, string subnav)
    {
        this.MainNav = mainnav;
        this.SubNav = subnav;
    }
}

Your action method then comes out

public ActionResult Index(string mainnav, string subnav)
{
    return View(new IndexViewModel(mainnav, subnav));
}

This means your view has to be strongly typed:

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<YourNameSpace.IndexViewModel>" %>

In your view, you output the data like so:

myobj.mainnav = <%: Model.MainNav %>;

An alternative solution if you use MVC3, would be to use the dynamic ViewBag:

public ActionResult Index(string mainnav, string subnav)
{
    ViewBag.MainNav = mainnav;
    ViewBag.SubNav = subnav;
    return View();
}

which would be accessed in the page as so:

myobj.mainnav = <%: ViewBag.MainNav %>;

However, I would recommend that you read up on unobtrusive javascript and see if you can improve your design to avoid this specific problem.

Answer 2

If you are using MVC3 I would suggest passing the values into the ViewBag.

ViewBag.MainNav = "xxxx";
ViewBag.SubNav = null;

then on your view page, where you define the JavaScript and add the value.

if you dont have MVC 3 if you use ViewData["MainNav"]), to store your value has the same effect.

Answer 3

Did you try accessing parameters from Request in your view?

i.e.

Request.Params["mainnav"]

or

Request.Params["subnav"]

Works in MVC

Answer 4

i'm using following approach:

ViewModel.class:

public class TitleBodyModel
{
    public string Title { get; set; }

    public string Body { get; set; }

    public TitleBodyModel() { Title = Body = ""; }

    public TitleBodyModel(string t, string b) { this.Title = t; this.Body = b; }
}

In the main View:

@Html.Partial("_TitleBody" , new XXX.Models.TitleBodyModel("title", "body" ))

Then in a partial view:

@model XXX.Models.TitleBodyModel


<div class="bl_item">
    <div class="bl_title">@Model.Title</div>

    <div class="bl_body">@Model.Body</div>
</div>