aspnetwebstack-mvc-outputcache-issue

Issue:

Output cache not working properly using cache profiles. For example, with this configuration:

<caching>
  <outputCacheSettings>
    <outputCacheProfiles>
      <add name="CacheEvents" duration="3600" varyByParam="iDisplayStart;iDisplayLength;sSearch" />
    </outputCacheProfiles>
  </outputCacheSettings>
</caching>

Example:

[OutputCache(CacheProfile = "CacheEvents")]
public ActionResult Index()
{
  return View();
}

Reason:

Output cache ignores the varyByParam parameter configured at the cache profiles on the web.config. It leaves the varyByParam value as "*", so any change on any param discards the cache.

Evidence: https://github.com/aspnetwebstack/aspnetwebstack/blob/master/src/System.Web.Mvc/OutputCacheAttribute.cs#L23

Solution:

#1 Configure all the settings at the CacheOutputAttribute

[OutputCache(Duration = 3600, VaryByParam = "iDisplayStart;iDisplayLength;sSearch")]
public ActionResult Index()
{
  return View();
}

#2 Set the cache profile CacheOutputAttribute and configure the varyByParam parameter there too.

[OutputCache(CacheProfile = "CacheEvents", VaryByParam = "iDisplayStart;iDisplayLength;sSearch")]
public ActionResult Index()
{
  return View();
}

#3 Extends the CacheOutputAttribute providing the capability of taking the varyByParam value from cache profiles on web.config

[ParameterizedOutputCacheAttribute(CacheProfile = "CacheEvents")]
public ActionResult Index()
{
  return View();
}

Implementation:

using System.Web.Mvc;
using System.Web.Configuration;

namespace Unconnected.Mvc.Outputcache
{
    public class ParameterizedOutputCacheAttribute:OutputCacheAttribute
    {
        private const string sectionPath = "system.web/caching/outputCacheSettings";

        protected static OutputCacheProfileCollection profiles
        {
            get
            {
                var section = (OutputCacheSettingsSection)WebConfigurationManager.GetSection(sectionPath);
                if (section != null)
                {
                    return section.OutputCacheProfiles;
                }
                return null;
            }
        }

        public new string CacheProfile
        {
            get
            {
                return base.CacheProfile;
            }
            set
            {
                base.CacheProfile = value;

                if (profiles != null)
                {
                    var profile = profiles[value];
                    if (!(profile==null || string.IsNullOrWhiteSpace(profile.VaryByParam)))
                    {
                        this.VaryByParam = profile.VaryByParam;
                    }
                }
            }
        }
    }
}

Courtesy of Alexander Kouznetsov

Demo

Technical specifications:

• Developed using Visual Studio 2013
• MVC 4 Web Application (.NET Framework 4)
• DataTables jQuery plug-in (version 1.9.4) with server-side mode.

Source code

Activity Log

• Create application environment
  • Install visual studio 2013 for working with the same IDE at the time of the issue
  • Create MVC 4 web application
    • Configure cache profiles with the given configuration
    • Download DataTables jQuery plug-in (version 1.9.4)
    • Implement DataTables with server-side configuration
• Identifie the issue
  • Deeply understand the purpose and function of the output cache
  • Analize possible configurations of the output cache
  • Implement output cache in all possible ways
• Find the solution
  • Investigate viable options
  • Implement solutions in environment created in step 1
  • Document and communicate