Repeatable Callback Functions

If you have a callback function that you need to re-use multiple times, you can assign it to a variable, and then re-use.

1$userCondition = function ($query) {
2    $query->where('user_id', auth()->id());
3};
4 
5// Get articles that have comments from this user
6// And return only those comments from this user
7$articles = Article::with(['comments' => $userCondition])
8    ->whereHas('comments', $userCondition)
9    ->get();