InlineTemplate.php

<?php

namespace Drupal\Core\Render\Element;

use Drupal\Core\Render\Attribute\RenderElement;

/**
 * Provides a render element where the user supplies an in-line Twig template.
 *
 * Properties:
 * - #template: The inline Twig template used to render the element.
 * - #context: (array) The variables to substitute into the Twig template.
 *   Each variable may be a string or a render array.
 *
 * Usage example:
 * @code
 * $build['hello']  = [
 *   '#type' => 'inline_template',
 *   '#template' => "{% trans %} Hello {% endtrans %} <strong>{{name}}</strong>",
 *   '#context' => [
 *     'name' => $name,
 *   ]
 * ];
 * @endcode
 */
class InlineTemplate extends RenderElementBase {
    
    /**
     * {@inheritdoc}
     */
    public function getInfo() {
        $class = static::class;
        return [
            '#pre_render' => [
                [
                    $class,
                    'preRenderInlineTemplate',
                ],
            ],
            '#template' => '',
            '#context' => [],
        ];
    }
    
    /**
     * Renders a twig string directly.
     *
     * @param array $element
     *   The element.
     *
     * @return array
     */
    public static function preRenderInlineTemplate($element) {
        
        /** @var \Drupal\Core\Template\TwigEnvironment $environment */
        $environment = \Drupal::service('twig');
        $markup = $environment->renderInline($element['#template'], $element['#context']);
        $element['#markup'] = $markup;
        return $element;
    }

}