Observer (checkout_cart_product_add_after) Not Firing

Question

I cannot seem to figure out why this observer is not firing. Any help is appreciated!

config.xml

<config>
<modules>
    <JP_OrderWaveIntegration>
        <version>1.0.0</version>
    </JP_OrderWaveIntegration>
</modules>
<global>
     <models>
        <JP_OrderWaveIntegration_Model>
             <class>JP_OrderWaveIntegration_Model</class>
        </JP_OrderWaveIntegration_Model>
    </models>
    <events>
        <checkout_cart_product_add_after>
            <observers>
                <JP_OrderWaveIntegration_Model>
                    <class>JP_OrderWaveIntegration/observer</class>
                    <method>addSale</method>
                </JP_OrderWaveIntegration_Model>
            </observers>
        </checkout_cart_product_add_after>
    </events>
</global>

Observer.php

<?php
class JP_OrderWaveIntegration_Sales_Model {

    public function addSale($observer) {
        Mage::log('My log entry', null, 'sales_observer.log');
        die('test');
    }
}

Answer 1

The convention for Magento 1 is to have the direct child node of <observers> the same as the module's identifier; in this case, it would be <JP_OrderWaveIntegration>.

Hoever, the larger issue is that your class is misnamed. Change the name to JP_OrderWaveIntegration_Model_Observer. Magento 1 uses the directory file system to specify names for classes (I believe that it conforms to the PSR-0 standard).

Please let me know if that works, or if you have any other questions!