PrePluginActivateEvent example

    public function activatePlugin(Plugin $plugin)
    {
        $bootstrap = $this->getPluginByName($plugin->getName());
        $this->requirementValidator->validate($bootstrap->getPath() . '/plugin.xml', $this->release->getVersion());
        $context = new ActivateContext($plugin, $this->release->getVersion(), $plugin->getVersion());

        $this->events->notify(PluginEvent::PRE_ACTIVATE, new PrePluginActivateEvent($context, $bootstrap));

        $bootstrap->activate($context);

        $this->events->notify(PluginEvent::POST_ACTIVATE, new PostPluginActivateEvent($context, $bootstrap));

        $plugin->setActive(true);
        $plugin->setInSafeMode(false);
        $this->em->flush($plugin);

        return $context;
    }