[FIXED] How to extend entity classes with custom functions (business logic) in cakephp v3

Issue

In cakephp 3 (3.3.5, that is) I want to extend my entity classes with custom functions (business logic). For example:

namespace App\Model\Entity;

use Cake\ORM\Entity;

class Something extends Entity {
    public function isFoo() {
        return true;
    }
}

The corresponding table object looks like this:

namespace App\Model\Table;

use Cake\ORM\RulesChecker;
use Cake\ORM\Table;
use Cake\Validation\Validator;
use Cake\ORM\TableRegistry;
use App\Model\Entity\Something;   // produces an `unused import' warning

class SomethingsTable extends Table
{
    public function initialize(array $config)
    {
        parent::initialize($config);
        ...
    }

    ...
}

In the controller, I use this code to retrieve the entity from the database and call the custom function:

class SomeOtherController extends AppController {
    ...
    $this->loadModel('Somethings');
    $thing = $this->SomethingsTable->get($id);
    if ($thing->isFoo()) { ... }
    ...
}

However, this fails with a fatal error:

Error: Call to undefined method Cake\ORM\Entity::isFoo() 

Note, when I do a

<?= var_dump($thing,true); ?>

in the corresponding view, $thing is shown as of type Cake\ORM\Entity.

How can I change the table's get() function to return entities with the correct type "Something" ?

Solution

It should be:

$thing = $this->Somethings->get($id);

// not 
$thing = $this->SomethingsTable->get($id);

Thats why the Something entity is not used, but the default Entity class.

CakePHP autotables, since it can not find the SomethingsTableTable the default table class is used. Therefore also the default entity class is loaded. If your test method would contain a query to the db, there would have been an error thrown, saying that somethings_table does not exist.

Answered By - Tolga