This is the length of time in seconds that a template cache is valid. Once this time has expired, the cache will be regenerated.
$cachingmust be turned on (either 1 or 2) for$cache_lifetimeto have any purpose.A
$cache_lifetimevalue of -1 will force the cache to never expire.A value of 0 will cause the cache to always regenerate (good for testing only, to disable caching a more efficient method is to set
$caching= 0).If you want to give certain templates their own cache lifetime, you could do this by setting
$caching= 2, then set$cache_lifetimeto a unique value just before callingdisplay()orfetch().
If
$force_compile is
enabled, the cache files will be regenerated every time, effectively
disabling caching. You can clear all the cache files with the clear_all_cache()
function, or individual cache files (or groups) with the clear_cache() function.