So, here's what I'm thinking for the config file. This would seem to cover all of the bases, and still be simple to use, right? I thought of mapping to controllers instead of URI's/routes, but this seemed to make more sense so the application could change the underlying controllers if needed and still be covered.
Code:
<?php namespace Config;
class Filters
{
// Makes reading things below nicer,
// and simpler to change out script that's used.
public $aliases = [
'isLoggedIn' => 'App\Filters\Authentication'
];
// Always applied before every request
public $global = [
'isLoggedIn' => ['except' => 'login'],
'CodeIgniter\Filters\CSRF' => '*'
];
public $routes = [
'admin/*' => [
'before' => ['isLoggedIn'],
'after' => ['somethingElse']
]
];
}