MVC 3: How to render a view without its layout page when loaded via ajax?

Question

I am learning about Progressive Enhancement and I have a question about AJAXifying views. In my MVC 3 project I have a layout page, a viewstart page, and two plain views.

The viewstart page is in the root of the Views folder and thus applies to all views. It specifies that all views should use _Layout.cshtml for their layout page. The layout page contains two navigation links, one for each view. The links use @Html.ActionLink() to render themselves to the page.

Now I have added jQuery and want to hijack these links and use Ajax to load their content on the page dynamically.

<script type="text/javascript">
    $(function () {
        $('#theLink').click(function () {
            $.ajax({
                url: $(this).attr('href'),
                type: "GET",
                success: function (response) {
                    $('#mainContent').html(response);
                }
            });
            return false;
        });
    });
</script>

There are two ways I can think of to do this, but I don't particularly like either one:

1) I can take the entire View's contents and place them in a partial view, then have the main view call the partial view when it is rendered. That way, using Request.IsAjaxRequest() in the controller, I can return View() or return PartialView() based on whether or not the request is an Ajax request. I can't return the regular view to the Ajax request because then it would use the layout page and I'd get a second copy of the layout page injected. However, I don't like this because it forces me to create empty views with just a @{Html.RenderPartial();} in them for the standard GET requests.

    public ActionResult Index()
    {
        if (Request.IsAjaxRequest())
            return PartialView("partialView");
        else
            return View();
    }

Then in Index.cshtml do this:

@{Html.RenderPartial("partialView");}

2) I can remove the layout designation from _viewstart and specify it manually when the request is NOT Ajax:

    public ActionResult Index()
    {
        if (Request.IsAjaxRequest())
            return View(); // Return view with no master.
        else
            return View("Index", "_Layout"); // Return view with master.
    }

Does anyone have a better suggestion? Is there a way to return a view without its layout page? It would be much easier to explicitly say "don't include your layout" if it is an ajax request, than it would be to explicitly include the layout if it's not an ajax.

Cibis

Answer 1

In ~/Views/ViewStart.cshtml:

@{
    Layout = Request.IsAjaxRequest() ? null : "~/Views/Shared/_Layout.cshtml";
}

and in the controller:

public ActionResult Index()
{
    return View();
}

Dungeon

Can this be specified in the viewstart? – Cibis

Ewww, that feels nasty to me. My viewstart page is about the last page I'd expect some kind of logic to be found. – Watcher

@Matt Greer, you call it nasty, I call it DRY, subjective stuff anyway :-) – Dungeon

I have to admit, I didn't like it at first, but the amount of code it saves would seem to far outweight it's downside. It's a simple boolean if and doesn't really impose much IMO. I like it better than chopping my action methods in half every single time. Plus it prevents me from doing what you said Matt and potentially going down two giant logic paths in the action method. I either write the action to work the same in both cases, or write a new action. – Cibis

couldn't you do this in a base controller, set a property in the ViewData and use that? Then the line would be Layout = ViewBag.LayoutFile. – Scanner

I suppose I could, but really why create a baseController for one little line? – Cibis

This will not work if the view tries to inject content into a @section – Devolve

@Darin Is there a way to set this in the cotroller? – Typewriter

@Shimmy, yes, there is a way, you could use the proper overload of the View method which allows you to specify the layout when returning the ViewResult. – Dungeon

This works brilliantly BUT is there a way of only hiding the header but displaying the footer part of the layout file? – Shew

@Darin, than you so much for this, i was making a ajax post and used return View() as said here; but my content got updated with the layout , but this fixed the issue. i have a question , normal post using @UrlAction vs Ajax post which is fast for returning a view ? – Therein

@Shimmy see my answer – Kana

I think this breaks the separation of concerns principle; a view shouldn't be concerned about the way it is rendered. The controller on the other side has all the information necessary to decide what and how to render its results. – Kana

Answer 2

Just put the following code on the top of the page

@{
    Layout = "";
}

Peddada

This does not work because I want to be able to toggle the layout on or off based on whether or not it is requested via AJAX. This only allows you to turn off the layout, not toggle it. – Cibis

Why this has Vote ups ?? pls explain so I will vote up it too . – Unfriended

@UsmanY. You do not need to vote it up. But I do. My arguemnt go to google.com.pk/#q=mvc3%20view%20without%20layout . And It is perfect answer to that query. – Decentralize

The topic is about toggling the layout on two different scenarios. This answer just set's the layout to empty no matter what the scenario is. – Adelaideadelaja

Dude, this works and it is really nice. The scenario I use: The unauthorized user tries to log in, one doesn't want the error page to show links and so forth to an unauthorized user! Of course, it works for everything else also! – Sharyl

Here's why I upvoted it: I have 2 separate pages, one for UI, one for ajax queries. And in ajax page I don't need the masterpage Layout. Now, in VS2013 UPD4 you can just remove that "Layout = something" line, and it disapears. But in VS2013 REL1 - it is not enough. The materpage layout is still included, even the line is not there. So, implicitly setting it to "Layout = ''" helped in my situation. That also states "if you want for this code to work 100% - use Layout = '' whenever you really want to hide it.". P.S. I don't have choice of which VS to use. Customer's decision :( – Nanny

This might not answer the question in the OP but I upvoted it anyway, because It answered the question that I needed answered. – Egomania

Google led me to this particular answer when I asked how to prevent layouts from loading for partial views, because the default layouts included jquery loads that were causing the infamous "cannot call methods on dialog prior to initialization; attempted to call method open" in my partial views using in dialogues. that's why I upvoted the answer. – Subclavian

Answer 3

I prefer, and use, your #1 option. I don't like #2 because to me View() implies you are returning an entire page. It should be a fully fleshed out and valid HTML page once the view engine is done with it. PartialView() was created to return arbitrary chunks of HTML.

I don't think it's a big deal to have a view that just calls a partial. It's still DRY, and allows you to use the logic of the partial in two scenarios.

Many people dislike fragmenting their action's call paths with Request.IsAjaxRequest(), and I can appreciate that. But IMO, if all you are doing is deciding whether to call View() or PartialView() then the branch is not a big deal and is easy to maintain (and test). If you find yourself using IsAjaxRequest() to determine large portions of how your action plays out, then making a separate AJAX action is probably better.

Watcher

Answer 4

All you need is to create two layouts:

1. an empty layout

2. main layout

Then write the code below in _viewStart file:

@{
   if (Request.IsAjaxRequest())
   {
      Layout = "~/Areas/Dashboard/Views/Shared/_emptyLayout.cshtml";
   }
   else
   {
      Layout = "~/Areas/Dashboard/Views/Shared/_Layout.cshtml";
   }
 }

of course, maybe it is not the best solution

Canvas

Answer 5

You don't have to create an empty view for this.

In the controller:

if (Request.IsAjaxRequest())
  return PartialView();
else
  return View();

returning a PartialViewResult will override the layout definition when rendering the respons.

Kana

Answer 6

With ASP.NET 5 there is no Request variable available anymore. You can access it now with Context.Request

Also there is no IsAjaxRequest() Method anymore, you have to write it by yourself, for example in Extensions\HttpRequestExtensions.cs

using System;
using Microsoft.AspNetCore.Http;

namespace Microsoft.AspNetCore.Mvc
{
    public static class HttpRequestExtensions
    {
        public static bool IsAjaxRequest(this HttpRequest request)
        {
            if (request == null)
            {
                throw new ArgumentNullException(nameof(request));
            }

            return (request.Headers != null) && (request.Headers["X-Requested-With"] == "XMLHttpRequest");
        }
    }
}

I searched for a while now on this and hope that will help some others too ;)

Resource: https://github.com/aspnet/AspNetCore/issues/2729

Arytenoid

Answer 7

For a Ruby on Rails application, I was able to prevent a layout from loading by specifying render layout: false in the controller action that I wanted to respond with ajax html.

Rollie

tags: c# asp.net, not ruby – Management