Handy Cache helper method

I love this little thing.

public static T FromMemory<T>(string Key, Func<T> func, double days = 7) where T : class
	var value = MemoryCache.Default.Get(Key) as T;
	if (value == null)
		value = func();

		if (value != null)
			MemoryCache.Default.Add(Key, value, DateTime.Now.AddDays(days));

	return value;

Then, instead of simply retrieving something from storage, e.g.

var items = LoadSiteMap();

You do this slightly awkward, but fairly clean alternative:

var items = Latest.FromMemory("SiteMap", LoadSiteMap);

You do have to tell it the cache_key to use.

You can override the default duration to hold it in memory (in days)...

var items = Latest.FromMemory("SiteMap", LoadSiteMap, 0.1);

And if things go really pear shaped, and it can't infer the types, you might need to specify them, for example here:

var items = Latest.FromMemory<List<ISitemapItem>>("SiteMap", LoadSiteMap, 0.1);

Note on Lambdas

tip Note that prior to C# version 6 we had to write those lambdas more explicitly....

() => LoadSiteMap()

...using "Full Lambda" instead of "Method Group" syntax.

See also