Events

Shortcodes provides events for extending its functionality. Modules and plugins can register event listeners, typically in their init() methods, to change Shortcodes’ behaviour.

Template Handler Events

The beforeRender Event

The event that is triggered before a shortcode mapped to a Twig template is rendered.

It's a plain yii\base\Event whose sender is the TemplateHandler for the shortcode. The handler's code property holds the shortcode name, template holds the template path, and context holds the variables the template will receive. These include shortcode, the matched element for the current route (such as entry) and any context passed to the shortcodes filter. Change $event->sender->context to add or replace template variables, or $event->sender->template to render a different template. The event can't stop the shortcode from rendering. Shortcodes mapped to a PHP class don't trigger it.

use verbb\shortcodes\handlers\TemplateHandler;
use yii\base\Event;

Event::on(TemplateHandler::class, TemplateHandler::EVENT_BEFORE_RENDER, function(Event $event) {
    /** @var TemplateHandler $handler */
    $handler = $event->sender;

    if ($handler->code === 'button') {
        $handler->context['buttonClass'] = 'btn btn-primary';
    }
});