c# - Setting HTTP cache control headers in Web API

Question

What's the best way to set cache control headers for public caching servers in WebAPI?

I'm not interested in OutputCache control on my server, I'm looking to control caching at the CDN side and beyond (I have individual API calls where the response can be indefinitely cached for the given URL) but everything I've read thus far either references pre-release versions of WebAPI (and thus references things that seem to no longer exist, like System.Web.HttpContext.Current.Reponse.Headers.CacheControl) or seems massively complicated for just setting a couple of http headers.

Is there a simple way to do this?

Answer 1

As suggested in the comments, you can create an ActionFilterAttribute. Here's a simple one that only handles the MaxAge property:

public class CacheControlAttribute : System.Web.Http.Filters.ActionFilterAttribute
{
    public int MaxAge { get; set; }

    public CacheControlAttribute()
    {
        MaxAge = 3600;
    }

    public override void OnActionExecuted(HttpActionExecutedContext context)
    {
        if (context.Response != null)
            context.Response.Headers.CacheControl = new CacheControlHeaderValue()
            {
                Public = true,
                MaxAge = TimeSpan.FromSeconds(MaxAge)
            };

        base.OnActionExecuted(context);
    }
}

Then you can apply it to your methods:

 [CacheControl(MaxAge = 60)]
 public string GetFoo(int id)
 {
    // ...
 }