MVC 5 Passing 2 Queries to View

Question

I have a HomeController which has a Navigation ActionResult to perform a query to get the top level elements:

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    return View(navigationModel);
}

I then have a Navigation View which outputs the results like so:

@model IEnumerable<WebApplication1.Models.Navigation>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
    }
</ul>

I would like so add a second navigation layer so contemplating something like:

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    var contentModel = (from n in db.Contents where (n.NavigationId = navigationModel.Id) orderby n.Position select n);
    return View(navigationModel, contentModel);
}

I get the error Cannot convert method group 'Id' to non-delegate type 'int?'. Did you intend to invoke the method?

I would like also like to pass the second query to the View, something like:

@model IEnumerable<WebApplication1.Models.Navigation>
@model IEnumerable<WebApplication1.Models.Contents>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
        <ul>
        @foreach (var item in Model)
            {
                @Html.MenuLink(item.Title, "Article", "Home")
            }
        </ul>
    }
</ul>

I realise my use of models may be completely inaccurate, just trying to emphasise what data where.

Any help would be much appreciated :-)

Here are the Navigation and Content classes to assist with any solutions:

Navigation.cs

public partial class Navigation
{
    public int Id { get; set; }
    public string Title { get; set; }
    public Nullable<int> Position { get; set; }
    public bool Main { get; set; }
    public string Action { get; set; }
    public string Controller { get; set; }
}

Content.cs

public partial class Content
{
    public int Id { get; set; }
    public Nullable<int> NavigationId { get; set; }
    public string Title { get; set; }
    public string Content1 { get; set; }
    public Nullable<int> Position { get; set; }
    public string Image { get; set; }
    public string Sub { get; set; }
    public Nullable<bool> Active { get; set; }
    public string Url { get; set; }
    public string Summary { get; set; }
}

Despite the helpful advise I was still left with the error Operator '==' cannot be applied to operands of type 'int?' and 'method group' so tried an alternative method, which is to use a join query, so I have modified the MVC structures as follows:

NavigationViewModel

public class NavigationViewModel
{
    public int NavigationId { get; set; }
    public string NavigationTitle { get; set; }
    public string NavigationAction { get; set; }
    public string NavigationController { get; set; }

    public int ContentId { get; set; }
    public string ContentTitle { get; set; }
}

HomeController

public ActionResult Navigation()
{
    var navigationModel = from c in db.Contents
                            join n in db.Navigations on c.NavigationId equals n.Id
                            where (n.Main == true && c.Active == true)
                            orderby n.Position
                            select new NavigationViewModel()
                            {
                                NavigationId= n.Id,
                                NavigationTitle = n.Title,
                                NavigationAction = n.Action,
                                NavigationController = n.Controller,
                                ContentId = c.Id,
                                ContentTitle = c.Title
                            };

    return View(navigationModel);
}

Navigation

@model IEnumerable<WebApplication1.Models.NavigationViewModel>

@foreach (var item in Model)
{
    @item.NavigationId @item.NavigationTitle @item.NavigationAction @item.NavigationController @item.ContentId @item.ContentTitle
}

So this gets the data, but I have a similar issue to what I started with, how do I now step through the data so I have something like this:

<ul class="nav sf-menu clearfix">
// Loop through items
// Are there multiple intances of the NavigationId?
    // No
    <li>navigation link here</li>
    // Yes
    <li class="sub-menu">navigation link here
        <ul>
            // Loop through all content links
            <li>content link here</li>
            // End loop
        </ul>
    </li>
// End Loop
</ul>

Answer 1

You can use a view model for this:

public class NavigationViewModel
{
    public IEnumerable<Navigation> Navigations { get; set; }
    public IEnumerable<Content> Contents { get; set; }
}

Your view will take this view model:

@model YourNamespace.ViewModels.NavigationViewModel

You're controller will initialize this view model and pass it to the view:

public ActionResult Navigation() {
    var navigations = your query...
    var contents = your other query...

    return View(new NavigationViewModel {
        Navigations = navigations,
        Contents = contents
    });
}

And your view can access both Model.Navigations and Model.Contents.

Answer 2

Try using == instead of = for your compiler error (unless you really mean to call the delegate which I doubt).

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    var contentModel = (from n in db.Contents where (n.NavigationId.HasValue &&(n.NavigationId.value == navigationModel.Id)) orderby n.Position select n);
    return View(new Tuple<Navigation, Contents> (navigationModel, contentModel));
}

You may have to use a conversion such as toString() if you have casting complications.

For your second issue if you don't want to make a new class use a Tuple (http://www.dotnetperls.com/tuple).

@model Tuple<WebApplication1.Models.Navigation, WebApplication1.Models.Contents>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model.Item1)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
        <ul>
        @foreach (var item in Model.Item2)
            {
                @Html.MenuLink(item.Title, "Article", "Home")
            }
        </ul>
    }
</ul>