Interface: ICacheHelper  - X-Ref

Interface for all classes implementing CacheHelper functionality.

Class: CacheHelper  - X-Ref

Helper class for caching various elements in a single cache entry.

To get a cached value or compute it, use getCachedValue like this:
$this->getCachedValue( $callback );

To add HTML that should be cached, use addCachedHTML like this:
$this->addCachedHTML( $callback );

The callback function is only called when needed, so do all your expensive
computations here. This function should returns the HTML to be cached.
It should not add anything to the PageOutput object!

Before the first addCachedHTML call, you should call $this->startCache();
After adding the last HTML that should be cached, call $this->saveCache();