magento sales_order_place_after observer not working - php

Question

I have created an event observer that will send email on order completion.
I am sending email to email_address1 when a product is ordered from the category1 and sending email to email_address2 when a product is ordered from the cateogory2. Therefore I have created an observer event for this.
But when I click on the "Place Order" button nothing happens. What is the problem?
in magento/app/etc/modules/Custom_Email.xml:
<?xml version="1.0"?>
<config>
<modules>
<Custom_Email>
<codePool>local</codePool>
<active>true</active>
</Custom_Email>
</modules>
</config>
in magento/app/code/local/Custom/Email/etc/config.xml:
<?xml version="1.0"?>
<config>
<global>
<models>
<customemail>
<class>Custom_Email_Model</class>
</customemail>
</models>
<events>
<sales_order_place_after>
<observers>
<custom_email_order_observer>
<type>singleton</type>
<class>customemail/order_observer</class>
<method>sendOrder</method>
</custom_email_order_observer>
</observers>
</sales_order_place_after>
</events>
</global>
</config>
in magento/app/code/local/Custom/Email/Model/Order/Observer.php:
<?php
class Custom_Email_Model_Order_Observer
{
public function __contruct()
{
}
/**
* Exports new orders to an xml file
* #param Varien_Event_Observer $observer
* #return Feed_Sales_Model_Order_Observer
*/
public function sendOrder($observer){
$order = $observer->getEvent()->getOrder();
$cat_id = Mage::getModel('catalog/layer')->getCurrentCategory()->getId();
echo $cat_id;
//Implement logic here
...
$emailTemplate = Mage::getModel('core/email_template')
->loadDefault('rehab');
$emailTemplateVariables = array();
$emailTemplateVariables['order'] = $order;
$emailTemplate->setSenderName('Your shops name');
$emailTemplate->setSenderEmail('addres#from.com');
$emailTemplate->setTemplateSubject('Subject');
$emailTemplate->send('to#addres.com','Name', $emailTemplateVariables);
echo 'email sent';
}
}
?>
So any one know where is the problem?

Answer 1

The layer does not exist in the order context, nor is the category from which the product was selected available as a property of quote or order items. It's a known deficiency in Magento which unfortunately limits segmentation.