controller.php

<?
$this->autoRender = false;            
if($this->request->is('ajax'))        
{                                     
                                      
  $day = $this->request->data('day');
  $data = array(                      
    'mister' => 'x',                  
    'affe' => $day                   
  );                                  
  return json_encode($data);          
}                                     

js.coffee

data = {                                        
  'trainingLength' : 20,                        
  'day' : 8,                                    
  'month' : 8,                                  
  'year' : 2014                                 
}                                               
$.ajax "#{ma.url}programs/updateTrainingVisual",
  success : (data, textStatus, jqXHR) ->        
    console.log data                            
                                                
  error : (jqXHR, textStatus, errorThrown) ->   
    console.log 'error'