Laravel orderBy on a relationship

I believe you can also do:

$sortDirection = 'desc';

$user->with(['comments' => function ($query) use ($sortDirection) {
    $query->orderBy('column', $sortDirection);
}]);

That allows you to run arbitrary logic on each related comment record. You could have stuff in there like:

$query->where('timestamp', '<', $someTime)->orderBy('timestamp', $sortDirection);

It is possible to extend the relation with query functions:

<?php
public function comments()
{
    return $this->hasMany('Comment')->orderBy('column');
}

[edit after comment]

<?php
class User
{
    public function comments()
    {
        return $this->hasMany('Comment');
    }
}

class Controller
{
    public function index()
    {
        $column = Input::get('orderBy', 'defaultColumn');
        $comments = User::find(1)->comments()->orderBy($column)->get();

        // use $comments in the template
    }
}

default User model + simple Controller example; when getting the list of comments, just apply the orderBy() based on Input::get(). (be sure to do some input-checking ;) )