add event for cache update

[icewind1991]

Allows app to also listen to updates and not just inserts

[MorrisJobke]

Code makes sense 👍

[kesselb]

server/lib/private/Files/Cache/Cache.php

Lines 309 to 315 in d16cfb5

	/**
	* update the metadata of an existing file or folder in the cache
	*
	* @param int $id the fileid of the existing file or folder
	* @param array $data [$key => $value] the metadata to update, only the fields provided in the array will be updated, non-provided values will remain unchanged
	*/
	public function update($id, array $data) {

💥

[MorrisJobke]

@icewind1991 🏓

[icewind1991]

#15413