Symphony event filters

<?php

/**
 * Extension driver
 *
 * @package Lalala
 * @author Michael E.
 */
class extension_lalala extends Extension
{
    /**
     * Delegates and callbacks
     *
     * @return array
     */
    public function getSubscribedDelegates()
    {
        return array(
            array(
                'page'     => '/blueprints/events/new/',
                'delegate' => 'AppendEventFilter',
                'callback' => 'appendEventFilter'
            ),
            array(
                'page'     => '/blueprints/events/edit/',
                'delegate' => 'AppendEventFilter',
                'callback' => 'appendEventFilter'
            ),
            array(
                'page'     => '/frontend/',
                'delegate' => 'EventPreSaveFilter',
                'callback' => 'eventPreSaveFilter'
            ),
            array(
                'page'     => '/frontend/',
                'delegate' => 'EventPostSaveFilter',
                'callback' => 'eventPostSaveFilter'
            ),
            array(
                'page'     => '/frontend/',
                'delegate' => 'EventFinalSaveFilter',
                'callback' => 'eventFinalSaveFilter'
            ),
        );
    }

    /**
     * Append event filters to event pages
     *
     * @param string $context
     * @return void
     */
    public function appendEventFilter($context)
    {
        $selected = !is_array($context['selected']) ? array() : $context['selected'];

        $context['options'][] = array(
            'my-filter',
            in_array('my-filter', $selected),
            __('My Filter')
        );
        $context['options'][] = array(
            'my-filter-2',
            in_array('my-filter-2', $selected),
            __('My Filter 2')
        );
        $context['options'][] = array(
            'my-filter-3',
            in_array('my-filter-3', $selected),
            __('My Filter 3')
        );
    }


    /**
     * eventPreSaveFilter
     *
     * @uses EventPreSaveFilter
     * @param string $context
     * @return void
     */
    public function eventPreSaveFilter($context)
    {
        if (in_array('my-filter-2', $context['event']->eParamFILTERS)) {
            // do something
        }
    }

    /**
     * eventPostSaveFilter
     *
     * @uses EventPostSaveFilter
     * @param string $context
     * @return void
     */
    public function eventPostSaveFilter($context)
    {
        if (in_array('my-filter-3', $context['event']->eParamFILTERS)) {
            // do something
        }
    }

    /**
     * eventFinalSaveFilter
     *
     * @uses EventFinalSaveFilter
     * @param string $context
     * @return void
     */
    public function eventFinalSaveFilter($context)
    {
        if (in_array('my-filter', $context['event']->eParamFILTERS)) {
            // do something
        }
    }
}