Call method form custom module Class

Question

I tried to call a function inside other class inside the same module on D8 but I have some error on the code. I got a Error: Class 'Drupal\hospitator\TimeTrackerController\TimeTracker' not found.

My main controller (HospitatorController.php):

namespace Drupal\hospitator\Controller;

use Drupal\Core\Controller\ControllerBase;
use Drupal\hospitator\TimeTrackerController\TimeTracker;

/**
 * Class HospitatorController.
 */
class HospitatorController extends ControllerBase {

  /**
   * Main Page Function.
   *
   * @return array
   *   Return main page.
   */
  public function mainPage() {
    $element = array(
        '#type' => 'markup',
        '#markup' => $this->t('Welcome to Hospitator!') . '<br/>',
    );
    $test_controller = new TimeTracker;
    $test_text = $test_controller->start();

    return $element;
  }

}

My secondary class (TimeTracker.php):

<?php

namespace Drupal\hospitator\TimeTrackerController;

use Drupal\Core\Controller\ControllerBase;

/**
 * Class TimeTracker.
 */
class TimeTracker extends ControllerBase {

  /**
   * Test Time Trakcker.
   *
   * @return string
   *   Return test text.
   */
  public function start() {
    $element = 'Test';
    return $element;
  }

}

I have been 2 years without coding and my memory have some leaks. Can you help me? Tanhk you,

Answer 1

Since Drupal 8 supports PSR-4 namespaces, as described in the Drupal coding standards, in the Namespaces document page, Modules section, there must be a correspondence between namespace and directory structure. This means that, if Drupal\hospitator\TimeTrackerController is the namespace, then the class file must be placed in the hospitator/src/TimeTrackerController folder. Furthermore, if TimeTracker is the class name, then the file containing its code must be named TimeTracker.php.
I assume that hospitator is the machine name of the module. If the machine name is different, then hospitator must be replaced from the module machine name, in the namespace and in the folder name.

If the file containing the class code is in hospitator/src/Controller/TimeTracker.php, then the correct namespace is Drupal\hospitator\Controller, not Drupal\hospitator\TimeTrackerController. When you reference that class in a file that is using another namespace, you add use Drupal\hospitator\Controller\TimeTracker; on the top of that file, not use Drupal\hospitator\TimeTrackerController\TimeTracker;.

Also, if the HospitatorController and the TimeTracker classes are using the same namespace, which I assume is Drupal\hospitator\Controller, there is no need to add use Drupal\hospitator\Controller\TimeTracker; on the top of the file containing the HospitatorController class.