CODEWITHSUNDEEP
asp.net-mvc
Vinney Kelly
Vinney Kelly

Reputation: 5095

Find MVC template view by name

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?

Upvotes: 5

Views: 1760

Answers (3)

Vinney Kelly
Vinney Kelly

Reputation: 5095

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.

Upvotes: 4

Jorge
Jorge

Reputation: 18257

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

Upvotes: 0

CodeCaster
CodeCaster

Reputation: 151674

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?

Upvotes: 0

Related Questions