Magento JSON formatter, Mage_Webhook_Model_Formatter_Json: Magento extensibility alpha-1

Mage_Webhook_Model_Formatter_Json.php

class Mage_Webhook_Model_Formatter_Json implements Mage_Webhook_Model_Formatter_Interface
{
    const CONTENT_TYPE = 'application/json';
 
    const FORMAT = "json";
    /**
     * @param Mage_Webhook_Model_Event_Interface $event
     * @return Mage_Webhook_Model_Message
     */
    public function format(Mage_Webhook_Model_Event_Interface $event)
    {
        $message = $this->newMessage();
        $message->setMapping($event->getMapping());
        $headers = $event->getHeaders();
        $headers[Mage_Webhook_Model_Formatter_Interface::CONTENT_TYPE_HEADER] = self::CONTENT_TYPE;
        $bodyData = $event->getBodyData();
        $encodedData = json_encode($bodyData);
        if (false === $encodedData) {
            throw new LogicException("The data provided cannot be encoded as json.");
        }
        $message->setHeaders($headers);
        $message->setBody($encodedData);
        return $message;
    }
 
    /**
     * @param Mage_Webhook_Model_Message_Interface $message
     * @return Mage_Webhook_Model_Message_Interface
     */
    public function decode(Mage_Webhook_Model_Message_Interface $message)
    {
        $message->setResponseData(
            json_decode($message->getResponseBody(), true)
        );
        return $message;
    }
 
    public function newMessage() {
        return Mage::getModel('Mage_Webhook_Model_Message');
    }
}
Data Format Factory

Data format factory will be used to create the data format based on the configuration. A data format factory needs to implement interface 'Mage_Webhook_Model_Formatter_Factory_Interface'. 'getFormatter' method needs to be implemented in the data format factory. Here is the details of interface 'Mage_Webhook_Model_Formatter_Factory_Interface'.
interface Mage_Webhook_Model_Formatter_Factory_Interface
{
    /**
     * @param $format string indicating the format used
     * @return Mage_Webhook_Model_Formatter_Interface
     */
    public function getFormatter($format);
}

Here is the implementation of JSON format factory that is provided by default in Magento.
class Mage_Webhook_Model_Formatter_Factory_Json implements Mage_Webhook_Model_Formatter_Factory_Interface
{
    const XML_PATH_DEFAULT_OPTIONS = 'global/webhook/formats/json/options/';
 
    protected $_config;
 
    public function __construct(Mage_Core_Model_Config $config)
    {
        $this->_config = $config;
    }
 
    /**
     * @param $format string indicating the format used
     * @return Mage_Webhook_Model_Formatter_Interface
     */
    public function getFormatter($format)
    {
        $modelName = (string) $this->_config->getNode(
            self::XML_PATH_DEFAULT_OPTIONS . 'format/' . $format . '/formatter'
        );
 
        if (!$modelName) {
            $modelName = (string) $this->_config->getNode(self::XML_PATH_DEFAULT_OPTIONS . 'default_formatter');
        }
 
        if (!$modelName) {
            throw new LogicException(
                "There is no specific formatter for the format given $format and no default formatter."
            );
        }
 
        $formatter = $this->getModel($modelName);
        if (!$formatter instanceof Mage_Webhook_Model_Formatter_Interface) {
            throw new LogicException("Wrong Formatter type for the model found given the format $format.");
        }
 
        return $formatter;
    }
 
    protected function getModel($modelName)
    {
        // TODO: probably here we should pass only format configuration options
        return Mage::getModel($modelName, $this->_config);
    }
}