CakePhp 3 Plugin Authentication adapter was not found - php

Question

I'm kinda a newbie in Cakephp (3.5) and I'm currently trying to make my first plugin (called Example) which contains several sub-directories. One of them is the UserManager directory which contains a Users MVC standard suit with authentication.
Since I want to add social logins and other stuffs, I created my own auth component as explained in the docs :
plugins/Example/UserManager/src/Controller/AppController.php
<?php
namespace Example\UserManager\Controller;
use App\Controller\AppController as BaseController;
class AppController extends BaseController
{
public function initialize()
{
parent::initialize();
$this->loadComponent('Auth', [
'authenticate' => [
'Example/UserManager.Example' => [
'fields' => ['username' => 'email', 'password' => 'pass'],
'userModel' => 'Users',
],
],
]);
}
}
plugins/Example/UserManager/src/Auth/ExampleAuthenticate.php
<?php
namespace App\Auth;
use Cake\Auth\BaseAuthenticate;
use Cake\Http\ServerRequest;
use Cake\Http\Response;
class ExampleAuthenticate extends BaseAuthenticate
{
// The same as Form authentication, since I'm testing
}
The problem is that I can't make the authentication component find the ExampleAuthenticate class. I already tried by setting the authenticate config param like
Example
ExampleAuthenticate
UserManager.Example
Example/UserManager.Example
Example\UserManager.Example
Example/UserManager.ExampleAuthenticate
Example\UserManager.ExampleAuthenticate
but I always get the error Authentication adapter "..." was not found. when visiting http://localhost/Project/example/user-manager/users :(
Does anyone have any clue of what I might be missing?

Answer 1

The problem was that the php function class_exists(...) didn't recognise the custom authentication class, so after digging a bit more I realised that the namespace shown in the docs only works for a custom authentication file defined in the App environment, but not in the Plugin one (silly me).
So I changed namespace App\Auth; to namespace Example\UserManager\Auth; inside ExampleAuthenticate.php and it worked like a charm! now the function class_exists('Example\\UserManager\\Auth\\ExampleAuthenticate') returns true and everything works perfect by defining Example/UserManager.Example in the authenticate config params.