Controller doesn't get hasOne relationship data - Cakephp - cakephp

Question

I have a problem with related tables in CakePHP. I can't get the related table data include in the form.
I have two Entities. One of them is "Users" and the other one is "Subjects". Every User has a subject. Table "Subject" has foreign key idUser from Users table.
I added in UsersTable:
$this->hasOne('Subjects');
And I added in SubjectsTable:
$this->belongsTo('Users', [
'foreignKey' => 'idUser',
'joinType' => 'INNER'
]);
In the view (signup), I have this:
<div class="form-group">
<?php echo $this->Form->control('Subject.name',['label' => 'Asignatura','placeholder' => 'Ingrese asignatura','class' => 'form-control']) ?>
</div>
In the controller, I have this:
$user = $this->Users->patchEntity($user, $this->request->getData(),['associated' => 'Subjects']);
When I debug $user, I am getting this result:
\src\Controller\UsersController.php (line 113)
object(App\Model\Entity\User) {
'id' => '11111111',
'name' => 'Leo',
'firstlastname' => 'Messi',
'secondlastname' => 'Cuccittini',
'email' => 'leo.messi#gmail.com',
'password' => '$2y$10$E02nd/w89BDvgCyz36bQdeBbujOLrSdON1e6CD25aDYCP2VeLkNNm',
'role' => '2',
'[new]' => true,
'[accessible]' => [
'id' => true,
'name' => true,
'firstlastname' => true,
'secondlastname' => true,
'email' => true,
'password' => true,
'role' => true
],
'[dirty]' => [
'id' => true,
'name' => true,
'firstlastname' => true,
'secondlastname' => true,
'email' => true,
'password' => true,
'role' => true
],
'[original]' => [],
'[virtual]' => [],
'[hasErrors]' => false,
'[errors]' => [],
'[invalid]' => [],
'[repository]' => 'Users'
}
So, I am not getting in the controller the data from Subject.
Any help, please.

Answer 1

Model
$this->hasOne('Subjects', [
'foreignKey' => 'userId'
]);
Controller:
$user = $this->User->get($id, ['contain' => ['Subjects']);
Entity/User.php
protected $_accessible = [
'subjects' => true
// ...
];
Form
https://book.cakephp.org/3.0/en/views/helpers/form.html#associated-form-inputs
Change: Subject.name to user.subject.name
<?php echo $this->Form->control('user.subject.name',['label' => 'Asignatura','placeholder' => 'Ingrese asignatura','class' => 'form-control']) ?>