Magento's Observer event isn't working and using webservices inside a Observer class - web-services

Question

I'm trying to create a dynamic product discount using values from a webservice.
I've searched some guides on the internet about this matter and I found that I needed to use checkout_cart_product_add_after and checkout_cart_update_items_after.
However, I followed some guides. Created my own module (which is visible in Magento back office: Configuration > Advanced > Modules) and a observer for this module. I didn't create anything more but it's not working. Since I can see the module in that menu, I believe the problem is on the observer/event call.
Here is the config.xml (which is inside app\code\local\namespace\MyModule\etc) for my module:
<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
<namespace_MyModule>
<version>0.1.0</version>
</namespace_MyModule>
</modules>
<global>
<events>
<checkout_cart_product_add_after>
<observers>
<namespace_MyModule_Discount>
<class>MyModule/Observer</class>
<method>MyModulePriceChange</method>
</namespace_MyModule_Discount>
</observers>
</checkout_cart_product_add_after>
</events>
</global>
</config>
And this is my Observer (which is inside app\code\local\namespace\MyModule\Model) for my module:
<?php
class namespace_MyModule_Model_Observer
{
public function MyModulePriceChange(Varien_Event_Observer $obs)
{
// Get the quote item
$item = $obs->getQuoteItem();
// Ensure we have the parent item, if it has one
$item = ( $item->getParentItem() ? $item->getParentItem() : $item );
// Load the custom price
$price = $this->_getPriceByItem($item);
// Set the custom price
$item->setCustomPrice($price);
$item->setOriginalCustomPrice($price);
// Enable super mode on the product.
$item->getProduct()->setIsSuperMode(true);
}
protected function _getPriceByItem(Mage_Sales_Model_Quote_Item $item)
{
$price = 4;
//use $item to determine your custom price.
return $price;
}
}
?>
Also, is it possible do call soap client to use a webservice inside a observer?
I hope my question is clear, thank you in advance for helping.

Answer 1

I see some issues with your config.xml. First of all, use capitalized both company name and module name. namespace_MyModule will become your namespace.
You have to declare models under global section like this:
<models>
<mycompany_mymodule>
<class>Mycompany_Mymodule_Model</class>
</mycompany_mymodule>
</models>
This will tell magento you want to use mycompany_mymodule for models in your module, and class name of each module will start with Mycompany_Mymodule_Model.
Where Mycompany and Mymodule are respective to folders of your module: app/code/local/Mycompany/Mymodule.
The modules section of config.xml should also have this namespace (Mycompany_Mymodule), matching name of your file app/etc/modules and folder structure in app/code/local.
The observers then become the following (I added type, and changed class):
<observers>
<namespace_MyModule_Discount>
<type>singleton</type>
<class>mycompany_mymodule/Observer</class>
<method>MyModulePriceChange</method>
</namespace_MyModule_Discount>
</observers>
Then try to test your observer method by adding there some code like die("message").

Answer 2

You haven't declared the models tag in the config.xml file.
An observer is a model after all and magento will not know where to find it (that MyModule/Observer you reference). Below it's an example of declaring models tag:
<models>
<MyModule>
<class>Namespace_Modulename_Model</class>
</MyModule>
</models>
Yes, you can do soap api calls inside observer.