Merge events by user and file

[nickvergessen]

@jGleitz would be nice if you are willing to test this.
Just download the file from https://raw.githubusercontent.com/nextcloud/files_downloadactivity/1afc446b61cc24418dd476db8e95ddf9899882a5/lib/Activity/Provider.php
and replace your apps/files_downloadactivity/lib/Activity/Provider.php file with this new version.

Sample

Fix #11

[jGleitz]

Wow, this was really fast!

The PR generally works as I would expect.

I however noticed that it never merges more than 5 file into one activity log. If a user dowloaded n files, I get ceil(n / 5) entries in the activity view.

I don’t have an activity where a file was downloaded by more than 5 users before something different happened, so I can’t say if the same behaviour applies for users.

[jGleitz]

I just discovered that the same applies for any other activity in the activity log. In older versions of own-/Nextcloud, more than five files where truncated to “and others”. This doesn’t seem to happen anymore, more that five files simply get split into more entries.

So I guess the behaviour isn’t a bug of this PR.

See nextcloud/activity#122

[nickvergessen]

Yeah, it's a code design decision in the servers code:
https://github.com/nextcloud/server/blob/da9468522b9e846d10b6e91ad10fa0c1b3b99546/lib/private/Activity/EventMerger.php#L225-L226

I dropped the "others"-tooltip, because otherwise we would have needed another API endpoint for the desktop and mobile clients, since they can't use tooltips like we do.