I have an MVC3 site using Razor as its view engine. I want my site to be skinnable. Most of the possible skins are similar enough that they can derive from a shared master layout.
Therefore, I am considering this design:
However, I would like to be able to call RenderSection in the bottom layer, _Common.cshtml, and have it render a section that is defined in the top layer, Detail.cshtml. This doesn't work: RenderSection apparently only renders sections that are defined the next layer up.
Of course, I can define each section in each skin. For instance, if _Common needs to call RenderSection("hd") for a section defined in Detail, I just place this in each _Skin and it works:
#section hd {
#RenderSection("hd")
}
This results in some duplication of code (since each skin must now have this same section) and generally feels messy. I'm still new to Razor, and it seems like I might be missing something obvious.
When debugging, I can see the complete list of defined sections in WebViewPage.SectionWritersStack. If I could just tell RenderSection to look through the entire list before giving up, it would find the section I need. Alas, SectionWritersStack is non-public.
Alternatively, if I could access the hierarchy of layout pages and attempt execution of RenderSection in each different context, I could locate the section I need. I'm probably missing something, but I don't see any way to do this.
Is there some way to accomplish this goal, other than the method I've already outlined?
This is in fact not possible today using the public API (other than using the section redefinition approach). You might have some luck using private reflection but that of course is a fragile approach. We will look into making this scenario easier in the next version of Razor.
In the meantime, here's a couple of blog posts I've written on the subject:
http://blogs.msdn.com/b/marcinon/archive/2010/12/08/optional-razor-sections-with-default-content.aspx
http://blogs.msdn.com/b/marcinon/archive/2010/12/15/razor-nested-layouts-and-redefined-sections.aspx
#helper ForwardSection( string section )
{
if (IsSectionDefined(section))
{
DefineSection(section, () => Write(RenderSection(section)));
}
}
Would this do the job ?
I'm not sure if this is possible in MVC 3 but in MVC 5 I am able to successfully do this using the following trick:
In ~/Views/Shared/_Common.cshtml write your common HTML code like:
<!DOCTYPE html>
<html lang="fa">
<head>
<title>Skinnable - #ViewBag.Title</title>
</head>
<body>
#RenderBody()
</body>
</html>
In ~/Views/_ViewStart.cshtml:
#{
Layout = "~/Views/Shared/_Common.cshtml";
}
Now all you have to do is to use the _Common.cshtml as the Layout for all the skins. For instance, in ~/Views/Shared/Skin1.cshtml:
#{
Layout = "~/Views/Shared/_Common.cshtml";
}
<p>Something specific to Skin1</p>
#RenderBody()
Now you can set the skin as your layout in controller or view based on your criteria. For example:
public ActionResult Index()
{
//....
if (user.SelectedSkin == Skins.Skin1)
return View("ViewName", "Skin1", model);
}
If you run the code above you should get a HTML page with both the content of Skin1.cshtml and _Common.cshtml
In short, you'll set the layout for the (skin) layout page.
Not sure if this will help you, but I wrote some extension methods to help "bubble up" sections from within partials, which should work for nested layouts as well.
Injecting content into specific sections from a partial view ASP.NET MVC 3 with Razor View Engine
Declare in child layout/view/partial
#using (Html.Delayed()) {
<b>show me multiple times, #Model.Whatever</b>
}
Render in any parent
#Html.RenderDelayed();
See the answer link for more use-cases, like only rendering one delayed block even if declared in a repeating view, rendering specific delayed blocks, etc.
Related
I'm converting an ASP.NET Forms app (that I didn't write) to an MVC 3 app. The ClientScriptManager is used in the old app. ClientScriptManager doesn't exist in MVC 3. What replaced ClientScriptManager? I've done enough reading to know that CSM has something to do with AJAX functionality in ASP.NET; it registers "sets" of js scripts and functions somewhat akin to how EditorTemplates work for sets of similar controls. I'm not necessarily looking to implement a CSM in MVC; I just want to know what practices Microsoft put in place that rendered CSM obsolete.
ASP.Net MVC was designed to give you complete control over the HTML and js, rather than having the framework render these for you, as with ASP.Net. So, nothing really "replaces" the ClientScriptManager. As a result, it is entirely up to you how you handle your js.
You can do something simple like include <script ...> tags to reference inline script or js files in your _Layout.cshtml file, or you could use some sort of JavaScript Loader like RequireJS or come up with your own scheme entirely using "Html Helpers" or something.
MVC 4 introduced the concept of bundling which lets you define collections of scripts as "bundles" and have MVC automatically minify and merge them together for you when you reference them in your Views like this :
#Scripts.Render("~/bundles/jquery")
Below is an example for rendering the JavaScript(Function) from Controller.
Controller
public ActionResult Index(int? id)
{
ViewBag.MyAlert = "<script type='text/javascript'>MyAlert();</script>";
}
View
<script src="Your Path" type="text/javascript"></script>
#Html.Raw(ViewBag.MyAlert)
JS
function MyAlert() {
alert('Hi');
}
Below is an example for rendering the JavaScript(File) from Controller.
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
StringBuilder sb = new StringBuilder();
sb.Append("<script src='Your Path' type='text/javascript'></script>");
filterContext.HttpContext.Response.Write(sb.ToString());
}
So using this approach you do not need to mentioned following code in View.
<script src="Your Path" type="text/javascript"></script>
I have the following setup
LayoutBasic.cshtml defining my head and body section + a #RenderSection("Extra", required: false);
LayoutTabPage.cshtml using LayoutBasic.cshtml defining the layout of a tab page
SpecificTabPageIndex.cshtml using LayoutTabPage.cshtml defining a #section Extra{} with some link and style tags
Sometimes I have a partial that contains the #section Extra{} rendered from within the SpecificTabPageIndex.cshtml
The problem is that it that the "Extra" section is not rendered. Sometimes the code runs fine but the section is not rendered and sometimes I get the "The following sections have been defined but have not been rendered for the layout page" error.
Can anyone give me a hint as to what I'm doing wrong? Is RenderSection unusable when nesting layouts in as many levels as I do?
TIA
./kroogar
Sometimes I have a partial that contains the #section Extra{}
Partials cannot have sections. That is a non supported scenario.
I have a page:
#Html.Action("Index", "Product")
#Html.Action("Index", "Vendor")
both of these contain:
#section Head {
...
}
and (of course), my layout file contains:
<head>
...
#RenderSection("Head", required:false)
</head>
the idea being that every page that has something for the head (like javascript includes, css, etc.) can do it via the section. The problem is that only one definition per page seems allowed. How is this generally handled?
I would not recommend using Section within the results of RenderAction as this is generally used for View Pages and not partials.
It would be better to have the following in your hosting layout page:
#section Head {
#Html.Action("foo")
#Html.Action("bar")
}
I couldn't find a nice way to do this, so I instead added properties to my base ViewModel that would hold the information that needed to go in the <head>, and then have a RenderPartial("Head") in my layout page. This way things are slightly more strongly-typed too, rather than just having any page put random junk in:
// Views/Shared/Head.cshtml
#model ViewModel
#foreach (var site in model.AuthorSites)
{
<link rel="me" type="text/html" href="#site" />
}
I want to create a reusable ajax control in MVC .NET using RAZOR.
my example is a simple ajax text box and list where the user filters the list by typing in the text box. on the first call i would render both the text box and the list using my razor view. on subsequent AJAX calls i would want to ONLY render the (now filtered) list.
idea 1: use #if statement to conditionally render code.
problem: razor does not seem to like conditionally written html. for example it errors when a <div> tag is not followed by a closing </div>.
idea 2: use #section tokens to create portions of my control and then call RenderSection within the same file as needed.
problem: razor does not allow RenderSection to call sections in the same page
i know i can conditionally render html as strings, but i wanted to take advantage of the legibility of the razor markup and keep with development protocols.
You should be able to output <div> tags in a Razor block without the corresponding </div> tag by surrounding it with <text>. The reason is that Razor uses the closing tag to know when to drag back into code-parsing mode:
#if (myCondition)
{
<text>
<div>
</text>
}
As for the Section stuff, you might be able to achieve what you want using Templated Razor Delegates, like this:
#{
Func<dynamic, object> b = #<strong>#item</strong>;
}
// ...
<span>This sentence is #b("In Bold").</span>
See Phil Haack's blog for a little more on this.
Just wanted to add a class="myClass" in body tag. Is there any html helper or something else can do this in MVC3 view page? Please advise, thanks.
This is very similar to Aaron's solution, but doesn't have the weight of a section (which at least in my mind, are for larger blocks of content than a single string). The simplest way is to pass a variable with the ViewBag.
In your layout, just print out the class for the body tag, plus any other page specific variables (page title, extra css/js scripts, etc...)
_Layout.cshtml:
<html>
<title>#ViewBag.Title</title>#* Can easily add in per page titles too *#
<body class="#ViewBag.BodyClass">
#RenderBody()
</body>
</html>
Then, variables set in your view get passed upwards to the layout:
Index.cshtml:
#model MyViewModel
#{
ViewBag.Title = "This page title!";
ViewBag.BodyClass = "...";
}
While you may have full control of the HTML a solution was what was needed so here is one ;-)
In the _layout.cshtml page
<body class="#RenderSection("BodyClass", false)">
This will look for a section in all the child pages but says don't worry if it can't find one
Then in your child views just do this
#section BodyClass {productList}
Keep it on one line and then the outputted HTML will look fine, also you can then build up the class names as well.
#section BodyClass {productList generic}
This idea goes perfect with DOM-Ready page specific code, why not checkout
http://paulirish.com/2009/markup-based-unobtrusive-comprehensive-dom-ready-execution/
Or my extended version here
https://github.com/AaronLayton/H5BP-Core
My way lets you do page specific code, but allows you to keep all of the Javascript in separate pages so each page becomes easily manageable. The final step would be to concatenate and minify all the JS into 1 file ;-)