Laravel 5: Need to sort a grouped collection by an attribute of first item of each group

Question

I have a collection of some Eloquent model items from my database which are grouped by an attribute using groupBy() , I need to sort that collection by another attribute of the first item of each group but preserve the initial structure. How can I achieve this, if possible at all?

Answer 1

groupBy returns a collection, so you should still be able to use the sortBy method. You need to use a callback to get the attribute value from the first item in each group rather than just giving it a string.

$sorted = $groups->sortBy(function ($group, $key) {
    return $group->first()->someAttribute;
});