Boolean-safe default filter

gistfile1.php

<?php

class DefaultBooleanFilterExtension extends \Twig_Extension {

	public function getFilters() {
		return array(
			new \Twig_SimpleFilter('defaultBoolean', array($this, 'default_boolean')),
		);
	}

	public function default_boolean($value, $default) {
		if ($value !== false && empty($value)) {
			return $default;
		} else {
			return $value;
		}
	}

	/**
	 * Returns the name of the extension.
	 *
	 * @return string The extension name
	 */
	public function getName() {
		return 'default_boolean_filter_extension';
	}

}