I am writing an HtmlHelper extension and I need to search for the existence of a template by name. The template in question may be a display or editor template depending on the context. My initial thought was to use ViewEngines.Engines.FindPartialView method. However, it appears that this method is not searching the ~/Views/Shared/DisplayTemplates and ~/Views/Shared/EditorTemplates directories.
I suppose this is for good reason. After all, how would the ViewEngine know whether to return the display or editor template without some additional information of context?
So, that leads to the question: how can I search for a specific EditorTemplate/DisplayTemplate I've considered adding a custom view engine to the ViewEngines collection to include these locations. I'm concerned, however, that this might be problematic.
My main concern is that the DisplayTemplate/EditorTemplate view might be served up for something unintended. Does anyone else see this as a problem?
Is it a better idea just to new up a specific DisplayTemplateViewEngine/EditorTemplateViewEngine instance when necessary and keep the ViewEngines collection clear of this specific functionality?
Is there something else I'm missing?
I absolutely love that the MVC framework is open source! I was able to determine, from the TemplateHelpers class (internal to the MVC Runtime) that the DataBoundControlMode is considered when rendering a template. The answer was simple! All I have to do is prefix the template name with the appropriate template director. So, to find a display template:
var metadata = ModelMetadata.FromLambdaExpression(expression, HtmlHelper.ViewData);
ViewEngines.Engines.FindPartialView(
_controllerContext,
string.Format("DisplayTemplates/{0}", metadata.TemplateHint))
No additional view engines or routing required! In case you're interested in the application, my helper is auto-generating UI components for a given model. I wanted to enable the existence of a custom template to bypass the automated rendering.
A WebFormViewEngine has a few properties that define (patterns for) locations to search for views.
You either follow the convention of the view engine you use, or create a custom view engine (that for examlpe extends Razor) with custom view paths.
The latter is explained here:
public class CustomViewEngine : RazorViewEngine
{
public CustomViewEngine()
{
var viewLocations = new[] {
"~/Views/{1}/{0}.cshtml",
"~/Views/Shared/{0}.cshtml",
"~/Views/Shared/DisplayTemplates/{0}.cshtml",
"~/Views/Shared/DisplayTemplates/{1}/{0}.cshtml",
// etc
};
this.PartialViewLocationFormats = viewLocations;
this.ViewLocationFormats = viewLocations;
}
}
So I guess in your helper you should look up the current view engine and look up its view location paths and search them in order. Doesn't an Html helper have a method or property for getting the view you're currently running in?
Why you just map the relative path
string path = Server.MapPath("~/View/");
And then check if the file exits base on the .cshtml exit's in that specific directory
string fileName = "MyView.cshtml";
if (File.Exists(path + fileName))
//do somethings
else
//do another things
Related
Is it possible in ASP.NET MVC 5 to dynamically create a partial view (cshtml) in the /Views/Shared directory? I have a situation where people are going to upload a bunch of HTML as strings and was thinking it would be better for performance to store them on the file system.
Is it as simple as creating a new file, steaming a string and saving?
Yes it is possible
Simply make a view like DynamicView.cshtml
#model DynamicView
#Html.Raw(Model.HTMLString)
Now the method you will use to store both the HTML and the pointer to it is a different story. You can either store the sanitized HTML in a data-base and retrieve it with a call to the Controller like
public ActionResult DynamicView(ind id)
{
DynamicView model = new DynamicView();
DynamicView.HTMLString = dbContext.HTMLViews.Where(v => v.id == id);
return View(model);
}
If you wish to write the submitted HTML to files instead, you can instead do
public ActionResult DynamicView(string filePath)
{
DynamicView model = new DynamicView();
DynamicView.HTMLString = ...code that reads file
return View(model);
}
See this related post Writing/outputting HTML strings unescaped
Quick Answer: No (you cannot/should not modify Views Folder at RunTime.)
ASP.NET MVC Views and Shared Views are meant to be compiled and run. Modifying them or Adding new ones as the Application is running is not at all advisable or practical.
What would make more sense is for you to store the uploaded html blobs in a database, file system, storage blob (cloud). Then code your Shared View or Specific Views to retrieve specific html blobs from the stored location depending upon which user is logged in.
There are a whole lot of Extension Functions in MVC that Enable you to insert partial html in views. take a look at PartialExtensions as an starting point.
I had a requirement to create top menu which will generate from DB. I tried a lot to create it using partial view. But i found most of the cases partial view is use for static content. at last i fond some helpful tutorial please find the following i hope it will help you too.
click here to see how to create Dynamic Partial view
As we know, when we create an MVC application, it creates its own typical structure which is known as convention over configuration and its a good practice .
It configure views, controller and model separately .
My concern is, can i architect(design) it like :
If I do that, My viewengine will search views inside view not inside subfolders and there are so many things like routing will get changed.. and so on..
Actually I dont want to construct my view,controller or model in a typical way, I want to put my view separately according to my domain, not according to controller like MVC does.
However in case of controller we can use any folder structure . I am specific about model,views and routing should not be affected as well.
And it is all about "Convention over My own Configuration".
Can someone please explain, how to get it done or any other alternatives.
Thanx
Anupam.
It sounds like what you are looking for is 'Areas'. This allows you to separate your controllers & views into separate 'area' folders.
More information can be found here, as including the necessary information to get this set up in this answer is probably not practical:
http://msdn.microsoft.com/en-GB/library/ee671793(v=vs.100).aspx
The location and folder structure of your controllers and models doesn't really matter, should work either way. Controllers are located by their type and classname.
The viewengine by default does search subfolders, trying to match with the naming of your controller. It searches multiple locations.
Now, if you want to change how the view engine searches for files you can configure it in global.asax. Have a look here regarding RazorViewEngine for example.
Personally I have gone away from the view engine auto locating my views and instead use relative paths for all of them because I think it makes it more readable overall.
Below is an example of a configured view engine and a relative path.
global.asax
ViewEngines.Engines.Clear();
var razorEngine = new RazorViewEngine() { FileExtensions = new string[] { "cshtml" } };
ViewEngines.Engines.Add(razorEngine);
controller action
return View("~/Views/Home/Index.cshtml", model);
Hope I understood your question correctly.
So far I have reached to conclusion.
The thing we have to consider for this are :
1.Need to override ControllerFactory : we have to search controller in specific location or assembly reference.(by default controller factory just chak the controller name )
2.Need to override ViewEngine : We have to change view search location according to our need.
3.Little modification in Route : we have to specify module name in routs for proper redirection.
route will be something like :
routes.MapRoute(
name: "Default",
url: "{module}/{controller}/{action}/{id}",
defaults: new { module = "HR", controller = "Home", action = "Index", id = UrlParameter.Optional }
);
will implement it soon. Your suggestions are most welcome.
I am building an application using Play for Model and Controller, but using backbone.js, and client side templating. Now, I want the html templates to be served by Play without any backing controller. I know I could put my templates in the public directory, but I would like to use Play's templating engine for putting in the strings in my template from the message file. I do not need any other data, and hence dont want the pain of creating a dummy controller for each template. Can I do this with Play?
You could create a single controller and pass in the template name as a parameter, but I am not sure if it is a good idea.
public static void controller(String templateName) {
// add whatever logic is needed here
renderTemplate("Controller/"+templateName+".html");
}
Then point all your routes to that controller method. Forget about reverse routing, though.
I think I would still rather have a separate controller method for each template. Remember that you can use the #Before annotation (see Play Framework documentation) to have the message string handling in exactly one place, that is executed before each controller method. By using the #With annotation you can even have this logic in a separate class.
You can use template engine from any place in your code:
String result = TemplateLoader.load("Folder/template.html").render(data);
Ok. Googling fail probably and I remember reading about this a while back but can't find it.
I have a View and a Partial View in different directories. In a view I say #Html.RenderPartial("[partial view name]"); how does RenderPartial figure out where to look? It must be a convention but what is it?
My view is in: WebRoot\Views\Admin\ folder and partial is at WebRoot\Views\Admin\Partials
Not sure if this the right set up.
I'm using MVC 3 (Razor engine)
you can, but you have to register the routes, to tell the view engine where to look for. example in Global.asax.cs you'll have:
ViewEngines.Engines.Add(new RDDBViewEngine());
and the class is:
public class RDDBViewEngine : RazorViewEngine
{
private static string[] NewPartialViewFormats = new[] {
"~/Views/Shared/Partials/{0}.cshtml" ,
"~/Views/{0}.cshtml"
};
public RDDBViewEngine()
{
base.PartialViewLocationFormats = base.PartialViewLocationFormats.Union(NewPartialViewFormats).ToArray();
}
}
{0} is for all the subfolders with partials.
Locating views is the responsibility of the ViewEngine. The WebFormViewEngine was the one originally shipped with MVC 1, and you can see the paths it searches on codeplex. Note that it searches the same paths for views and partial views.
The CshtmlViewEngine (Razor) introduced with MVC 3 (or rather WebMatrix) searches similar locations but looks for different extensions.
Each view engine registered in your application has a list of file patterns that will be searched when you reference a view using a simple name (you can also reference it using a full path e.g. ~\Views\Admin\View.aspx)
In MVC 3 the properties of the view engine specify the patterns to search for (this applies to Razor and WebForms view engines).
Instead of subclassing the RazorView engine (as was suggested by zdrsh) you can just alter existing RazorViewEngine's PartialViewLocationFormats property. This code goes in Application_Start:
System.Web.Mvc.RazorViewEngine rve = (RazorViewEngine)ViewEngines.Engines
.Where(e=>e.GetType()==typeof(RazorViewEngine))
.FirstOrDefault();
string[] additionalPartialViewLocations = new[] {
"~/Views/[YourCustomPathHere]"
};
if(rve!=null)
{
rve.PartialViewLocationFormats = rve.PartialViewLocationFormats
.Union( additionalPartialViewLocations )
.ToArray();
}
I want to use MVC views to create the body for an email and I have come across this (http://www.brightmix.com/blog/renderpartial-to-string-in-asp-net-mvc/) but it doesn't seem to work with strongly typed views (ViewContext is null). But I was after something the would render a full view including a masterpage.
I thought that if there was a way of just invoking a view with out redirecting and just writing to a different stream and sending the email within the controller that might do it, but I can't work out how to invoke a view.
Any suggestions would be great!
Thanks in advance.
Gifster
The question has been asked (and answered) already:
Render View as a String
This is the bit that I use:
protected string RenderViewToString<T>(string viewPath, T model, System.Web.Mvc.ControllerContext controllerContext) {
using (var writer = new StringWriter()) {
var view = new WebFormView(viewPath);
var vdd = new ViewDataDictionary<T>(model);
var viewCxt = new ViewContext(controllerContext, view, vdd, new TempDataDictionary(), writer);
viewCxt.View.Render(viewCxt, writer);
return writer.ToString();
}
}
Best place for this method is in a class library project that your mvc project has a reference to. Mainly because that way you can easily reuse it in all your apps. But also because it is neither Application logic (so doesn't belong in the controller) nor does it belong in the model. Some things are just utilities.
Note that to get this to work, the viewPath parameter HAS to be the PHYSICAL PATH to the file, complete with the .aspx extension. You can't use a route as WebFormView class requires a physical path in its constructor.
This will render the full view and take account of the master page.
HEALTH WARNING FOR HTML EMAILS:
HTML emails and the devices where you read them are even more difficult and restrictive to design for than websites and browsers. What works in one, will not work in another. So with html emails, you really have to Keep It Simple! Your lovely page with menus and relative images and whatever else, JUST WON'T WORK in all email devices. Just as an example, the images src attribute needs to be absolute and include the domain:
This won't work:
<img src="/Images/MyImage.gif" ... />
Bit this will:
<img src="http://www.mywebsite.com/Images/MyImage.gif" ... />
With those caveats, it works fine and I use it. Just don't try to send them the full gimmickry of your website, cos that won't work!
Even more important:
All CSS must be INLINE and just for basic styling: colours, borders, padding. But no floating and positioning. CSS layouts won't work consistently across devices!
You can use MvcView NuGet package to do this! Its simple, just install using install-package MvcMailer and you are done! Use full power of view engine to template, master page, view model and send html emails neatly!