Caching ChildActions using cache profiles won't work?

Question

I\'m trying to use cache profiles for caching child actions in my mvc application, but I get an exception: Duration must be a positive number.

My web.config looks li

Answer 1

Here's a simple way if :

• Your basic goal is to be able to disable cache during debugging, and enable it during deployment
• You don't have complicated caching policies (that mean you truly need to respect Web.config's caching settings)
• You don't have a complicated deployment system that relies on Web.config's caching syntax
• Ideal if you're using XDT web transformations already
• You just assumed it would already work and are annoyed that it didn't and need a quick fix!

All I did was created a new attribute 'DonutCache'.

[DonutCache]
public ActionResult HomePageBody(string viewName)
{
    var model = new FG2HomeModel();

    return View(viewName, model);
}

I store my caching setting in Web.config (under a new custom name - so as to avoid confusion).

I created a simple helper method to pull the value out.

public static class Config {
    public static int DonutCachingDuration
    {
        get
        {
            return int.Parse(ConfigurationManager.AppSettings["DonutCachingDuration"]);
        }
    }
}

Unfortunately you can only initialize an [Attribute] with a constant, so you need to initialize the attribute in its constructor (you cant just say [Attribute(Config.DonutCachingDuration)] unfortunately).

Note: This doesn't prevent you setting 'varyByParam' in the [DonutCache] declaration - which is currently the only other property that is usable for caching of Action methods.

class DonutCacheAttribute : OutputCacheAttribute
{
    public DonutCacheAttribute()
    {
        // get cache duration from web.config
        Duration = Config.DonutCachingDuration;
    }
}

Just use an XDT web transformation's and you're ready to deploy with a longer value.

Tip: You'll probably want to stick a @DateTime.Now.ToString() in your partial view to make sure the cache setting is being respected.