add context transformer to support closures

m-vo · m-vo · commit 2d26645ba429 · 2021-07-09T17:17:08.000+02:00
diff --git a/core-bundle/src/Resources/contao/library/Contao/TemplateInheritance.php b/core-bundle/src/Resources/contao/library/Contao/TemplateInheritance.php
@@ -11,6 +11,7 @@
 namespace Contao;
 
 use Contao\CoreBundle\Monolog\ContaoContext;
+use Contao\CoreBundle\Twig\Interop\ContextHelper;
 use Psr\Log\LogLevel;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -338,6 +339,11 @@ protected function getTemplatePath($strTemplate, $strFormat='html5', $blnDefault
 
 	private function renderTwigSurrogateIfExists(): ?string
 	{
+		if (!$this instanceof Template)
+		{
+			return null;
+		}
+
 		$container = System::getContainer();
 
 		if (null === ($twig = $container->get('twig', ContainerInterface::NULL_ON_INVALID_REFERENCE)))
@@ -349,7 +355,7 @@ private function renderTwigSurrogateIfExists(): ?string
 
 		if ($twig->getLoader()->exists($templateCandidate))
 		{
-			return $twig->render($templateCandidate, $this->arrData);
+			return $twig->render($templateCandidate, ContextHelper::fromContaoTemplate($this));
 		}
 
 		return null;
diff --git a/core-bundle/src/Twig/Interop/ContextHelper.php b/core-bundle/src/Twig/Interop/ContextHelper.php
@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of Contao.
+ *
+ * (c) Leo Feyer
+ *
+ * @license LGPL-3.0-or-later
+ */
+
+namespace Contao\CoreBundle\Twig\Interop;
+
+use Contao\Template;
+
+class ContextHelper
+{
+    /**
+     * Adjust Contao template data to seamlessly work as a Twig context.
+     */
+    public static function fromContaoTemplate(Template $template): array
+    {
+        $context = $template->getData();
+
+        array_walk_recursive(
+            $context,
+            static function (&$value, $key): void {
+                if (\is_callable($value)) {
+                    $value = self::getCallableWrapper($value, (string) $key);
+                }
+            }
+        );
+
+        return $context;
+    }
+
+    private static function getCallableWrapper(callable $callable, string $name): object
+    {
+        return new class($callable, $name) {
+            /**
+             * @var callable
+             */
+            private $callable;
+
+            /**
+             * @var string
+             */
+            private $name;
+
+            public function __construct(callable $callable, string $name)
+            {
+                $this->callable = $callable;
+                $this->name = $name;
+            }
+
+            /**
+             * Delegate call to callable, e.g. when in a Contao template context.
+             */
+            public function __invoke(...$args)
+            {
+                return ($this->callable)(...$args);
+            }
+
+            /**
+             * Called when evaluating `{{ var }}` in a Twig template.
+             */
+            public function __toString(): string
+            {
+                try {
+                    return (string) $this();
+                } catch (\Throwable $e) {
+                    // Enhance exception message
+                    throw new \RuntimeException("There was an error evaluating '{$this->name}': {$e->getMessage()}");
+                }
+            }
+
+            /**
+             * Called when evaluating `{{ var.invoke(…) }}` in a Twig template.
+             * We do not cast to string here, so that other types (like arrays)
+             * are supported as well.
+             */
+            public function invoke(...$args)
+            {
+                return $this(...$args);
+            }
+        };
+    }
+}
