Pass arguments to observer method using <args> node in Magento's observer design pattern

magentoObserverArgs.php

<?php
class Namespace_Module_Helper_Data extends Mage_Core_Helper_Abstract {
	
	/**
	 * Retrieve args node of observer config
	 * 
	 * @param Varien_Event_Observer $observer
	 * @return array $observerArgs
	 */
	public function getObserverArgs(Varien_Event_Observer $observer, $callingClass, $callingMethod) {
		
		/**
		* Define vars
		*/
		$usedObservers = array();
		$observerArgs = array();
		$eventObservers = array();
		
		/**
		 * Load Magento config
		 */
		$config = Mage::getConfig();
		
		/**
		 * Retrieve all observers attached to the current observer's event
		 */
		$eventObservers = (array) $config->getXpath('//events/' . $observer->getEvent()->getName() . '/observers/*');
		
		/**
		 * Retrieve all XML nodes of the current observer (including <args>!)
		 * and populate $usedObservers with observers that:
		 * - call the same class and method than the $observer passed as arguments for this function
		 * - have an <args> node declared in config
		 */
		foreach($eventObservers as $eventObserver) {
			$className = $config->getModelClassName($eventObserver->class);
			$method = $eventObserver->method;
			$args = (bool) $eventObserver->args;
			if($className == $callingClass && $method == $callingMethod && $args) {
				$usedObservers[] = $eventObserver;
			}
		}
		
		/**
		 * Create array of args
		 */
		foreach($usedObservers as $usedObserver) {
			$args = (array) $usedObserver->args;
			foreach($args as $name => $value) {
				$observerArgs[$name] = $value;
			}
		}
		
		$args = new Varien_Object;
		$args->setData($observerArgs);
		
		return $args;
	}
}

The observer is declared as shown below:

<events>
    <event_to_observe>
        <observers>
            <observer_name>
                <type>singleton</type>
                <class>Namespace_Module_Model_ObserverClass</class>
                <method>observerMethod</method>

                <args>
                    <arg_name>arg_value</arg_name>
                </args>

            </observer_name>
        </observers>
    </event_to_observe>
</events>

The helper method in the Gist is called as shown below from the observer method:

<?php
/**
 * Observer class
 */

class Namespace_Module_Model_ObserverClass {

    /**
     * Observer method
     * 
     * @param Varien_Event_Observer $observer
     * @return void
     */
    public function observerMethod(Varien_Event_Observer $observer) {

        $args = Mage::helper('ecmessenger')->getObserverArgs($observer, get_class($this), __FUNCTION__);
        //Mage::log($args, null, 'observer.log');
    }
}

Quick correction on the above comment:
$args = Mage::helper('ecmessenger')->getObserverArgs($observer, get_class($this), FUNCTION);

is

$args = Mage::helper('module')->getObserverArgs($observer, get_class($this), FUNCTION);

Grrr... Sorry...

$args = Mage::helper('module')->getObserverArgs($observer, get_class($this), __FUNCTION__);