gistfile1.txt

// UsersController.php

    public function edit($id = null)
    {
        $user = $this->Users->get($id);

        if ($this->request->is(['patch', 'post', 'put'])) {
            $user = $this->Users->patchEntity($user, $this->request->data);
            if ($this->Users->save($user)) {
                $this->Flash->success('The user has been saved.');
            } else {
                $this->Flash->error('The user could not be saved. Please, try again.');
            }
        }

        $this->set(compact('user'));
        $this->set('_serialize', ['user']);
    }
    
    
    
    // Template/Users/edit.ctp
    
    <?= $this->Form->create($user, ['id' => 'edit-form']); ?>
    <?= $this->Form->input('password'); ?>
    <?= $this->Form->submit();  ?>
    <?= $this->Form->end() ?>
    
    <script>
    var form = $('#edit-form');
    form.submit(function(e) {
        var post_data = form.serializeArray();
        var form_url = form.attr('action');
        var form_type = 'POST';
        var return_data_type = 'json';
        
        $.ajax({
            url: form_url,
            data: post_data,
            type: form_type,
            dataType : return_data_type,
    
            success: function(json) {
                // DOM changes to show success or any validation errors and flash messsage content
            },
    
            error: function( xhr, status, errorThrown ) {
                console.log( "Error: " + errorThrown );
                console.log( "Status: " + status );
                console.dir( xhr );
            },
            
            complete: function( xhr, status ) {
            }
        });
        e.preventDefault();
    });
    
    
    </script>