This is an add-in for Fody

Caches return values of methods decorated with an attribute.

Introduction to Fody

Nuget

Nuget package http://nuget.org/packages/CacheAttribute.Fody

To Install from the Nuget Package Manager Console

PM> Install-Package CacheAttribute.Fody

Base Cache Code

[AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public abstract class BaseCacheAttribute : Attribute
{
	public abstract T Retrieve<T>(MethodBase method, object[] args);

	public abstract void Store<T>(T t, MethodBase method, object[] args);
}

Your Code

Define your cache implementation by deriving from BaseCacheAttribute:

public class CacheAttribute : BaseCacheAttribute
{
	public CacheAttribute()
	{
		ArgumentOrder = -1;
		CacheValidityInMinutes = -1;
	}

	public string ReturnType { get; set; }

	public int ArgumentOrder { get; set; }

	public int CacheValidityInMinutes { get; set; }

    public override T Retrieve<T>(MethodBase method, object[] args)
    {
		if(string.IsNullOrWhiteSpace(ReturnType))
		{
			var m = method as MethodInfo;
			ReturnType = m.ReturnType.Name;
		}
		return Context.Current.Cache.Get<T>(GenerateCacheKey(ReturnType, ArgumentOrder, args));
    }

    public override void Store<T>(T t, MethodBase method, object[] args)
    {
        string key = GenerateCacheKey(CacheKey, ArgumentOrder, args);
		if(CacheValidityInMinutes > 0)
		{
			Context.Current.Cache.Set(key, t, TimeSpan.FromMinutes(CacheValidityInMinutes));
		}
		else
		{
			Context.Current.Cache.Set(key, t);
		}
    }
	
	private string GenerateCacheKey(string objectName, int argumentOrder, object[] args)
	{
		string key = objectName;
		if (argumentOrder >= 0)
		{
			key += ":" + args[argumentOrder];
		}
		return key;
	}
}

public class Sample
{
	[Cache(ArgumentOrder = 0)]
	public string GetStringById(string id)
	{
		string value;
	    switch(id){
			case "test":
				value = "foo";
			default:
				value = "bar";
		}
		return value;
	}
}

What gets compiled

public class Sample
{
	public string GetStringById(string id)
	{
	    MethodBase method = methodof(Sample.Method, Sample);
	    CacheAttribute attribute = (CacheAttribute) method.GetCustomAttributes(typeof(CacheAttribute), false)[0];
	    
		object[] args = new object[1] { (object) id };
		
		var returnValue = attribute.Retrieve<string>(method, args);
		if(returnValue != null)
		{
			return returnValue
		}
		
		string value;
	    switch(id){
			case "test":
				value = "foo";
			default:
				value = "bar";
		}
		
		attribute.Store(value, method, args);
		
		return value;
	}
}

Known limitations

• No log when compiling
• Add unit tests