在nopCommerce插件中使用CacheManager

Question

I have created a nopCommerce v3.5 plugin and want load a text file under a Controller Action to _cacheManager then reuse it in next requests.

But _cacheManager always return NULL to me for my request Key .

This is some part of my codes:

public class AbcController : Controller   
{
    private readonly ICacheManager _cacheManager;

    public AbcController(ICacheManager cacheManager)
    {
        this._cacheManager = cacheManager;
    }

    public ActionResult Test(string title,string titleLink, string backColor,  string textColor, string timeColor)
    {
        try
        {
           // myText is always NULL here >>   :(
           var myText = _cacheManager.Get<string>("myText");

           if (string.IsNullOrEmpty(jsText))
           {
              string path = HttpContext.Server.MapPath("~/plugins/Misc.Test/App_Data/text.txt");
              myText = System.IO.File.ReadAllText(path);

              // Fill cacheManager >> 
              _cacheManager.Set("myText", myText, int.MaxValue);
            }

            // Other codes ......
        }

        // Other codes ......
     }
}

• Do i forget some part of codes inside other classes? like register someone or...???

• What is my mistake?

Answer 1

NopCommerce has two cache managers.Both are declared at DependencyRegistrar.cs:

builder.RegisterType<MemoryCacheManager>().As<ICacheManager>().Named<ICacheManager>("nop_cache_static").SingleInstance();
builder.RegisterType<PerRequestCacheManager>().As<ICacheManager>().Named<ICacheManager>("nop_cache_per_request").InstancePerHttpRequest();

The default cache is the PerRequestCacheManager and you'll get an instance just by adding it to your controller constructor. If you want to use the static cache, you need to instruct Autofac to inject it when you configure the dependencies for your controller.

DependencyRegistrar.cs,

builder.RegisterType<MyController>()
                .WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"));

You really should use DI instead of adding an static reference to MemoryCacheManager. This way you could change the cache provider in the future if needed.

Answer 2

NopCommerce has two cache managers. You are getting an instance that works while processing the same http request, but does not span to other requests.

You need to inject an instance of the static cache manager. You can find all the info in my reply to this other question: Nopcommerce cache seems empty after adding a list .