CakePHP Ajax : update list with change in related list - cakephp

Question

I am working on CakePHP 2.7.8. I want to update related list with change in list using Ajax.
I have a customers table and customer_addresses table in the database and customers and customerAddress models in the project.
There is another controller serviceRequests where I have to select customer and address of the selected customer from a drop down list generated by CakePHP from database.
What I have done-
I have added a function getCustomerAddress in the serviceRequests controller
public function getCustomerAddress(){
$customer_id = $this->request->data['Post']['customer_id'];
$customer_address = $this->CustomerAddress->find('list',array(
'condition' => array('CustomerAddress.customer_id' => $customer_id),
'recursive' => -1
));
$this->set('customerAddresses', $customer_address);
$this->layout = 'ajax';
}
to display the retrieved data, I have a view get_customer_address.ctp
<?php
foreach ($customerAddresses as $key => $value): ?>
<option value="<?php echo $key;?>"><?php echo $value; ?></option>
<?php endforeach; ?>
In the add.ctp view of serviceRequests controller for add function, I have added following script at the last.
<div class="serviceRequests form">
<?php echo $this->Form->create('ServiceRequest'); ?>
<fieldset>
<legend><?php echo __('Add Service Request'); ?></legend>
<?php
echo $this->Form->input('customer_id');
echo $this->Form->input('customer_address_id');
echo $this->Form->input('status');
?>
</fieldset>
<?php echo $this->Form->end(__('Submit')); ?>
</div>
<?php
$this->Js->get('#ServiceRequestCustomerId')->event('change',
$this->Js->request(array(
'controller' => 'serviceRequests',
'action' => 'getCustomerAddress'
), array(
'update' => '#ServiceRequestCustomerAddressId',
'async' => true,
'method' => 'post',
'dataExpression' => true,
'data' => $this->Js->serializeForm(array(
'isForm' => true,
'inline' => true
))
))
);
?>
and to render Js, I have added following code to to last of default.ctp
<!-- script for layout -->
<?php echo $scripts_for_layout; ?>
<!-- Js writeBuffer -->
<?php
if(class_exists('JsHelper') && method_exists($this->Js, 'writeBuffer')) echo $this->Js->writeBuffer ();
// writes cached scripts
?>
But on accessing localhost/serviceRequests/add the ajax call is not working and all customer's name and all customer's addresses are showing in the list.

Answer 1

This is an example of how to implement chained selects with cake http://sandbox.dereuromark.de/sandbox/ajax_examples/chained_dropdowns
- the related article for that example is here http://www.dereuromark.de/2014/01/09/ajax-and-cakephp/