Pretty often when something is wrong with one of the Twig templates, we see just the "white screen"™ error on the Drupal rendered page, that gives no useful information about which Twig template rendering is failing!
Even in all the backtrace items we can't find any clue about what Twig template file caused the error!
Yes, we can put a breakpoint in the failing code line, analyze the backtrace, open the compiled Twig php file, and try to guess which original Twig file it is. But this is tooooo long way just to understand which Twig file is failing!
1. Make an error in a Twig template.
2. Open the page and see the "white screen" error like this:
The website encountered an unexpected error. Try again later.
TypeError: strlen(): Argument #1 ($string) must be of type string, array given in strlen() (line 395 of core/lib/Drupal/Component/Utility/Unicode.php).
Drupal\Component\Utility\Unicode::validateUtf8() (Line: 65)
Drupal\Component\Utility\Xss::filter() (Line: 796)
Drupal\Core\Render\Renderer->ensureMarkupIsSafe() (Line: 393)
Drupal\Core\Render\Renderer->doRender() (Line: 203)
Drupal\Core\Render\Renderer->render() (Line: 484)
Drupal\Core\Template\TwigExtension->escapeFilter() (Line: 55)
__TwigTemplate_45aaddb45b88363bac447fa181ac9b6d->doDisplay() (Line: 388)
Twig\Template->yield() (Line: 344)
Twig\Template->display() (Line: 359)
Twig\Template->render() (Line: 51)
Twig\TemplateWrapper->render() (Line: 33)
twig_render_template() (Line: 348)
Drupal\Core\Theme\ThemeManager->render() (Line: 446)
Drupal\Core\Render\Renderer->doRender() (Line: 203)
Drupal\Core\Render\Renderer->render() (Line: 484)
Drupal\Core\Template\TwigExtension->escapeFilter() (Line: 109)
__TwigTemplate_5ac5bdb663570f8a84422efbebb035e4->doDisplay() (Line: 388)
Twig\Template->yield() (Line: 344)
Twig\Template->display() (Line: 359)
Twig\Template->render() (Line: 51)
Twig\TemplateWrapper->render() (Line: 33)
twig_render_template() (Line: 348)
Drupal\Core\Theme\ThemeManager->render() (Line: 502)
Drupal\Core\Render\Renderer->doRender() (Line: 459)
Drupal\Core\Render\Renderer->doRender() (Line: 459)
Drupal\Core\Render\Renderer->doRender() (Line: 459)
Drupal\Core\Render\Renderer->doRender() (Line: 203)
Drupal\Core\Render\Renderer->render() (Line: 484)
Drupal\Core\Template\TwigExtension->escapeFilter() (Line: 90)
__TwigTemplate_af4c9328c361028bbc46bf8a7e616852->doDisplay() (Line: 388)
Twig\Template->yield() (Line: 344)
Twig\Template->display() (Line: 359)
Twig\Template->render() (Line: 51)
Twig\TemplateWrapper->render() (Line: 33)
twig_render_template() (Line: 348)
Drupal\Core\Theme\ThemeManager->render() (Line: 446)
Drupal\Core\Render\Renderer->doRender() (Line: 459)
Drupal\Core\Render\Renderer->doRender() (Line: 459)
Drupal\Core\Render\Renderer->doRender() (Line: 203)
Drupal\Core\Render\Renderer->render() (Line: 238)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 593)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() (Line: 246)
Symfony\Component\EventDispatcher\EventDispatcher::Symfony\Component\EventDispatcher\{closure}() (Line: 206)
Symfony\Component\EventDispatcher\EventDispatcher->callListeners() (Line: 56)
Symfony\Component\EventDispatcher\EventDispatcher->dispatch() (Line: 188)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 116)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 90)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 709)
Drupal\Core\DrupalKernel->handle() (Line: 19)
3. See no clue at all in this output about which Twig template file caused this exception.
Let's maybe make a subscriber for this type of exceptions, that will parse the backtrace and find the exact template file where this error is triggered, and add it to the exception message?
Active
11.0 🔥
theme system
Hi,
I am using drupal 11. When we make any error in twig file drupal shows the file name as well as the line number which is causing the error
For me sometimes yes, sometimes not, seems depends on the error type. I'll try to find a short case to reproduce it.