Creating Hello world event dispatcher(observer) in Magento?

Question

I am trying to create an event dispatcher in Magento (which should be called after a product gets added to cart).

What I\'ve done so far:

I Googled this and

Answer 1

Looking at your code downloaded from http://goo.gl/O7dBy you define:

    
        
            
                dispatcher/observer
                hookToAddToCartAfter
            
        
    

and define the model alias of dispatcher as:

    
        MyPackage_Crossdata_Dispatcher_Model
    

The resulting class name would be MyPackage_Crossdata_Model_Dispatcher_Model_Observer, but your observer class is named MyPackage_Crossdata_Dispatcher_Model_Observer, missing the Model in between Crossdata and Dispatcher.

I'd recommend to drop the whole dispatcher models definition above and only use the other model alias crossdata which you've already defined in config.xml:

    MyPackage_Crossdata_Model
    crossdata_mysql4
   

Then change the event definition to:

    crossdata/observer
    hookToAddToCartAfter

Create a file /app/code/local/MyPackage/Crossdata/Model/Observer.php and define your observer class in it:

class MyPackage_Crossdata_Model_Observer
{
    public function hookToAddToCartAfter($observer)
    {
        // your observer code
    }
}