ASP.net core MVC catch all route serve static file

Question

Is there a way to make a catch all route serve a static file?

Looking at this http://blog.nbellocam.me/2016/03/21/routing-angular-2-asp-net-core/

I basically want something like this:

        app.UseMvc(routes =>
        {
            routes.MapRoute("default", "{controller}/{action=Index}");

            routes.MapRoute("spa", "{*url}"); // This should serve SPA index.html
        });

So any route that doesn't match an MVC controller will serve up wwwroot/index.html

Solution 1

If you're already in the routing stage, you've gone past the point where static files are served in the pipeline. Your startup will look something like this:

app.UseStaticFiles();

...

app.UseMvc(...);

The order here is important. So your app will look for static files first, which makes sense from a performance standpoint - no need to run through MVC pipeline if you just want to throw out a static file.

You can create a catch-all controller action that will return the content of the file instead. For example (stealing the code in your comment):

public IActionResult Spa()
{
    return File("~/index.html", "text/html");
}

Solution 2

I had to make some additions to @DavidG answer. Here is what I ended up with

Startup.cs

app.UseStaticFiles();

app.UseMvc(routes =>
{
   routes.MapRoute("default", "{controller}/{action}");

   routes.MapRoute("Spa", "{*url}", defaults: new { controller = "Home", action = "Spa" });
});

HomeController.cs

public class HomeController : Controller
{
  public IActionResult Spa()
  {
      return File("~/index.html", "text/html");
  }
}

Solution 3

ASP.NET Core catch all routes for Web API and MVC are configured differently

With Web API (if you're using prefix "api" for all server-side controllers eg. Route("api/[controller"]):

app.Use(async (context, next) => 
{ 
    await next(); 
    var path = context.Request.Path.Value;

    if (!path.StartsWith("/api") && !Path.HasExtension(path)) 
    { 
        context.Request.Path = "/index.html"; 
        await next(); 
    } 
});            

app.UseStaticFiles();
app.UseDefaultFiles();

app.UseMvc();

With MVC (dotnet add package Microsoft.AspNetCore.SpaServices -Version x.y.z):

app.UseStaticFiles();
app.UseDefaultFiles();

app.UseMvc(routes => 
{ 
    routes.MapRoute( 
        name: "default", 
        template: "{controller=Home}/{action=Index}"); 

    routes.MapSpaFallbackRoute("spa", new { controller = "Home", action = "Index" }); 
});  

Solution 4

In case you don't want manually specify which routes are for api:

app.UseDefaultFiles();
app.UseStaticFiles();

app.UseMvc() // suggestion: you can move all the SPA requests to for example /app/<endpoints_for_the_Spa> and let the mvc return 404 in case <endpoints_for_the_Spa> is not recognized by the backend. This way SPA will not receive index.html

// at this point the request did not hit the api nor any of the files

// return index instead of 404 and let the SPA to take care of displaying the "not found" message
app.Use(async (context, next) => {
    context.Request.Path = "/index.html";
    await next();
});
app.UseStaticFiles(); // this will return index.html

Solution 5

What I'm using that works well is Microsoft.AspNetCore.Builder.SpaRouteExtensions.MapSpaFallbackRoute:

app.UseMvc(routes =>
{
    // Default route for SPA components, excluding paths which appear to be static files (have an extension)
    routes.MapSpaFallbackRoute(
        "spaFallback",
        new { controller = "Home", action = "Index" });
});

HomeController.Index has the equivalent of your index.html. You can probably route to a static page also.

A bit off topic, but if you also have an API in the same project under an api folder you can set a default 404 response for any API routes that don't match:

routes.MapRoute(
    "apiDefault",
    "api/{*url}",
    new { controller = "Home", action = "ApiNotFound" });

You would end up with the following behavior:

• /controller => No extension, so serve SPA default page from HomeController.Index and let SPA handle routing
• /file.txt => Extension detected, serve static file
• /api/controller => proper API response (use attribute routing or set up another map for the API controllers)
• /api/non-existent-route => 404 NotFound() returned from HomeController.ApiNotFound

In many cases you'll want an API in a separate project, but this is a viable alternative.

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