outputcache mvc3 only logged out user caching

Question

Is there a way to use the OutputCache attribute to cache the results of only logged out users and reevaluate for logged in users example:

What I'd Like

[OutputCache(onlycacheanon = true)]
public ActionResult GetPhoto(id){
   var photo = getPhoto(id);
   if(!photo.issecured){
      return photo...
   }
   return getPhotoOnlyIfCurrentUserHasAccess(id);
   //otherwise return default photo so please don't cache me
}

jgauffin · Answer 1 · 2014-06-25T08:14:01.470

8

You can use the VaryByCustom property in [OutputCache].

Then override HttpApplication.GetVaryByCustomString and check HttpContext.Current.User.IsAuthenticated.

Return "NotAuthed" or similar if not authenticated (activating cache)
Guid.NewGuid().ToString() to invalidate the cache

edited Jun 25 '14 at 08:14

answered Mar 28 '12 at 06:04

jgauffin

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1

That's the very thing I was missing thank you. I didn't realize null disabled caching. – maxfridbe Mar 28 '12 at 06:08
Didn't know it was available. Thank you :) – Mar 28 '12 at 10:09
5

`null` **does NOT** disable the cache. I've tried that solution on the sample project and it just caches separately for authenticated and non authenticated users... – Cheburek Apr 25 '12 at 10:57
@Cheburek You can return Guid.NewGuid().ToString() instead of null, which would make every request unique. But it would have some performance implications. – Doug Feb 21 '13 at 20:27

score 4 · Answer 2 · answered May 17 '12 at 11:43

This is how I implemented the above.

In Global.asax.cs:

public override string GetVaryByCustomString(HttpContext context, string custom)
{
    if (custom == "UserId")
    {
        if (context.Request.IsAuthenticated)
        {
            return context.User.Identity.Name;
        }
        return null;
    }

    return base.GetVaryByCustomString(context, custom);
}

Usage in Output Cache Attribute:

 [OutputCache(Duration = 30, VaryByCustom = "UserId" ...
 public ActionResult MyController()
 {
    ...

outputcache mvc3 only logged out user caching

2 Answers2