Add StaticFileResult

[davidfowl]

If I want to return a static file from an MVC controller action, I basically need to replicate some of the logic of the static file server. To make this easier, it would be great if there was a static file result that rendered content from the web root.

public class MyController : Controller
{
     [HttpGet("/")]
     [Authorize]
     public IActionResult Get()
     {
         return StaticFile("index.htm");
     }
}

In the above example I'm using MVC for auth but the action result for auth'd users renders the index file.

/cc @rynowak @danroth27 @SteveSandersonMS @Eilon

[rynowak]

I don't understand how this is different from https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNetCore.Mvc.Core/ControllerBase.cs#L1201
https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNetCore.Mvc.Core/Internal/VirtualFileResultExecutor.cs#L49

Is this mostly about the mime-type mapping?

[davidfowl]

@rynowak yes, whatever the static file middleware does when it gets a file, this needs to do as well. Maybe it's just mime mapping but I haven't looked to see if that is the only delta.

[rynowak]

We should find a way to expose and reuse that then. We don't have an O/L without a content type so it's something we could add.

[davidfowl]

@rynowak The static file result should just encapsulate that. The mime mapping could be a service.

/cc @Tratcher for awareness

[davidfowl]

Basically some of the in here (if not all) https://github.com/aspnet/StaticFiles/blob/d6c2834f95d69dfbb5a9cdd6bc54a1d510d27e4a/src/Microsoft.AspNetCore.StaticFiles/StaticFileContext.cs should be in this component.

[SteveSandersonMS]

Sounds good to me.

At first I thought it might not be necessary since applications can just combine FileExtensionContentTypeProvider and FileResult in a couple of lines to get a working result, but when you add in ETags and Range requests, it's way too complex to replicate in application code.

[Tratcher]

@jbagga is adding a lot of the missing functionality in #6150 (Ranges, conditionals, etc.).. The mime type lookup is one of the few missing pieces. The lookup is less critical from MVC, you're manually specifying the file name so you likely already know the mime type, it's not dynamic like it is for StaticFiles.

[sebastienros]

Aside from content-type could we also be able to specify content-disposition? It's important as it lets the action define the filename as seen from the client's perspective and if the client should trigger a download popup or not.

Example:
Content-disposition: attachment;filename=reports.csv

[Tratcher]

@sebastienros That's already available through FileDownloadName.

Mvc/src/Microsoft.AspNetCore.Mvc.Core/FileResult.cs

Line 41 in 760c8f3

public string FileDownloadName

[sebastienros]

@Tratcher great, and attachment ?

[Tratcher]

Yes,

Mvc/src/Microsoft.AspNetCore.Mvc.Core/Internal/FileResultExecutorBase.cs

Line 35 in 4cca6b0

var contentDisposition = new ContentDispositionHeaderValue("attachment");

[mkArtakMSFT]

We've moved this issue to the Backlog milestone. This means that it is not going to happen for the coming release. We will reassess the backlog following the current release and consider this item at that time. However, keep in mind that there are many other high priority features with which it will be competing for resources.