Perform actions when a text format has been updated.
This hook allows modules to act when a text format has been updated in any way. For example, when filters have been reconfigured, disabled, or re-arranged in the text format.
$format: The format object of the format being updated.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_filter_format_update($format) {
mymodule_cache_rebuild();
}