issue 6900

AppController.php

<?php
namespace App\Controller;

use Cake\Controller\Controller;

/**
 * Application Controller
 *
 * Add your application-wide methods in the class below, your controllers
 * will inherit them.
 *
 * @link http://book.cakephp.org/3.0/en/controllers.html#the-app-controller
 */
class AppController extends Controller
{

    /**
     * Initialization hook method.
     *
     * Use this method to add common initialization code like loading components.
     *
     * @return void
     */
    public function initialize()
    {
        parent::initialize();
        $this->loadComponent('Flash');
    }
}

index.ctp

<?php
echo $this->Html->link(__('Delete Selected'),
    ['controller' => 'Portfolios', 'action' => 'delete'],
    ['id' => 'delete', 'class' => 'btn btn-danger hidden margin-left',
          'confirm' => 'Are you sure you want to delete the selected portfolios?'
    ]
);

echo $this->Html->script('jquery');
?>
<input type="checkbox" checked name="delete_portfolio" class="delete" value="1">
<input type="checkbox" checked name="_csrfToken" class="delete" value="<?= $this->request->params['_csrfToken'] ?>">

<script>
$('a#delete').on('click', function(e) {
    e.preventDefault();
    $.post($(this).attr('href'), $('input.delete:checked').serialize());
})
</script>

PortfoliosController.php

<?php
namespace App\Controller;

use App\Controller\AppController;

class PortfoliosController extends AppController
{
    public function initialize()
    {
        $this->loadComponent('RequestHandler');
        $this->loadComponent('Csrf');
    }

    /**
     * Index method
     *
     * @return void
     */
    public function index()
    {
        // do nothing
    }

    public function delete() {
        debug($this->request->is('ajax'));
        debug($this->request->is('post'));
        debug($this->request->data);
        die();
    }
}