How to fix that symfony dd function shows a blank page? - php

Question

Symfony version 4.1.
Problem: when I use dd I see only a blank page. body tag does not contain anything. Doing I little dubugging I found that there are different types of debugging output: cli, html, server. And in my case var_dumper.server_dumper service was used as a debugger class. I do not know symfony so good to make some further steps. I guessed that there is service config file where I can pass html_dumper. But I did not find any related files. Symfony docs also show nothing about the configuration. Strange, but google also does not show any relevant results.
Want to add that I installed symfony 4.1 when it was not stable and then I usage of dd/dump gave the same result. But I have run composer update recently and now I should have a fresh symfony version. For long time I used xdebug but sometimes it is much easier to dump a var.
Update:
My code:
namespace App\Controller\SuperAdmin;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
class HomeController extends Controller
{
/**
* #Route("/", name="home")
* #return Response
*/
public function index()
{
dd(1);
return $this->render('super-admin/home/index.html.twig');
}
}

Answer 1

Update: Just verified that Symfony 4.1.1 has fixed this problem. dd now works as expected out of the box.
Some of this is discussed here: https://symfony.com/blog/new-in-symfony-4-1-vardumper-server
Basically, out of the box, Symfony 4.1 has:
# config/packages/dev/debug.yaml
debug:
# Forwards VarDumper Data clones to a centralized server allowing to inspect dumps on CLI or in your browser.
# See the "server:dump" command to start a new server.
dump_destination: "tcp://%env(VAR_DUMPER_SERVER)%"
The intent (I think) is to intercept debug strings and print them to a console using:
bin/console server:dump
So dd(1); will result in an output in the console as well as a blank web page in the browser. Not entirely sure the Symfony folks intended this to be the default behavior or not.
If you want dd(1) to appear in your html page then change the destination to null.
# config/packages/dev/debug.yaml
debug:
dump_destination: null
In any case, dump() continues to work as expected.
Look like this was in fact a bug: https://github.com/symfony/symfony/issues/27622
Should be fixed in the next 4.1.x release.