Cakephp 3.x update a record without form - cakephp

Question

In my users/index page I basically list every user in the users table by doing the following:
<?php foreach ($users as $user): ?>
<tr>
<td><?= h($user->name) ?></td>
<td><?= h($user->email) ?></td>
<td><?= h($user->phone_nr) ?></td>
<td><?= h($user->role)?></td>
</tr>
<?php endforeach; ?>
User.role field is an enum type with two choices: 'user' or 'admin'.
Instead of just listing the user's role, I need to have a dropdown to be able to change it right away. So basically I need something like:
echo $this->Form->input('role', ['type' => 'select','label' => 'Role', 'options' => ['user' => 'user', 'admin' => 'admin']]);
However, it doesn't work outside of a form and the table is obviously not a form.
Any help or guidance for how to solve is much appreciated.
EDIT
As requested, I provide the code snippet that is used to save user data (if saved from a form):
public function add()
{
$user = $this->Users->newEntity();
if ($this->request->is('post')) {
$user = $this->Users->patchEntity($user, $this->request->data);
if ($this->Users->save($user)) {
$this->Flash->success(__('The user has been saved.'));
return $this->redirect(['action' => 'index']);
} else {
$this->Flash->error(__('The user could not be saved. Please, try again.'));
}
}
}

Answer 1

A very simple approach could be the one described below. It makes use of no Ajax, just a simple POST request, which means the page is reloaded when the role is changed.
Modify your view as follows:
<?php foreach ($users as $user): ?>
<tr>
<td><?= h($user->name) ?></td>
<td><?= h($user->email) ?></td>
<td><?= h($user->phone_nr) ?></td>
<td><?= h($user->role)?></td>
<td>
<?= $this->Form->postButton('Toggle Role',
['controller'=>'users','action'=>'toggle_role',$user->id,$user->role])?>
</td>
</tr>
<?php endforeach; ?>
Add an action to your controller:
public function toggle_role($id,$existing_role){
$users = TableRegistry::get('Users');
$user = $users->get($id);
$user->role = ($existing_role == 'admin')?'user':'admin';
$users->save($user);
return $this->redirect($this->referer());
}
Note: The code is not tested, and lacks error handling
See
Creating Standalone Buttons and POST links