Helper function for getting/setting cache data

[johnjamesjacoby]

Most of the time when we want something from the object cache we go through a routine of: wp_cache_get(); checking a result; setting a default; setting the cache with wp_cache_set(); returning. Core should offer a neat way to do this all in one fell-swoop.

Attached patch is a proposed solution.

[scribu]

I've never needed to set a default when a cache value is not present.

Could you provide a usage example for the new function?

[scribu]

I'm particularly interested in how the callback parameter would work, knowing that generating a value to be cached would require various bits of information from the current context.

[wonderboymusic]

Assigning to JJJ to ping him about this

[nacin]

I'm going to close this for now.

As scribu said many months ago, you probably require a lot of information about the current process. Such a callback would likely be a closure that passes in information from current scope and such. Which is not bad, but this also isn't a pattern I've seen in any other caching backend, at least ones with popular PHP libraries. get/set/add/increment/decrement/etc are all standard. Something along the lines of "attempt" is not.

You also typically do not want to set a cache value until after you have performed your work and are positive things are successful. This would make things much more difficult to catch, wait, etc. It's just a bit over-abstracted.