Question

I have a single-page JavaScript application, held within an ASP.NET MVC 3 website.

In order to cache-bust the JS/CSS files used by the application, without the need for manually renaming files each time a change is made, I have the following routes & respective controller actions for serving static files.

Global.asax.cs

routes.MapRoute(
    "AppCssFile",
    "style.{version}.min.css",
    new { controller = "StaticFile", action = "CssFile" }
);

routes.MapRoute(
    "AppJsFile",
    "app.{version}.min.js",
    new { controller = "StaticFile", action = "JsFile" }
);

StaticFileController

//NB: m_JsAppFolder references below just point to the root folder for static files

[HttpGet]
public FileResult CssFile()
{
    var sourceFile = HttpContext.Server.MapPath(Path.Combine(m_JsAppFolder, "assets", "style", "release.css"));
    return new FilePathResult(sourceFile, "text/css");
}

[HttpGet]
public FileResult JsFile()
{
    var sourceFile = HttpContext.Server.MapPath(Path.Combine(m_JsAppFolder, "release.js"));
    return new FilePathResult(sourceFile, "text/javascript");
}

This works well, however the problem is that my Cache-Control header does not return the value I would expect…

As I have the following in my Web.config:

...
<urlCompression doStaticCompression="true" />
<staticContent>
    <!-- Set expire headers to 1 year for static content-->
<clientCache cacheControlCustom="public" cacheControlMode="UseMaxAge" cacheControlMaxAge="365.00:00:00" />
<!-- use utf-8 encoding for anything served text/plain or text/html -->
<remove fileExtension=".css" />
<mimeMap fileExtension=".css" mimeType="text/css" />
<remove fileExtension=".js" />
<mimeMap fileExtension=".js" mimeType="text/javascript" />
</staticContent>
...

I would expect to see a Cache-Control header of Cache-Control:public,max-age=31536000, in the same as if the CSS/JS files were referenced directly, rather than via a Controller Action.

Is there anyway to get MVC to treat a controller action response as staticContent: I don’t really want to have to manually set the Cache-Control header in my controller, as this would mean that both this setting and that in the Web.config could get out of sync.

Answer 1

Are you looking for the OutputCacheAttribute?

With this you can have your result cache in the server and the client using the properties Duration and Location.