Empty dump() output in Symfony CLI

Question

I'm building a simple Symfony-shell script to test my Symfony app on interactive mode:

# bin/app_dev_cli.php

require __DIR__.'/../app/autoload.php';

$kernel = new AppKernel('dev', true);
// Initialize bundles and container
$kernel->boot();

// Useful global vars
$container = $kernel->getContainer();
$doctrine = $container->get('doctrine');
$em = $doctrine->getManager();

Later, opening PHP interactive mode and including the previous script I can do some tasks quickly:

/path/to/symfony/project$ php -a
Interactive mode enabled

# Booting the Symfony-shell app
php > require 'bin/app_dev_cli.php';

# Check if one service has been registered successfully
php > dump( $container->has('some_service') );

# Test some service
php > dump( $container->get('some_service')->run($param) );

# Manage some entities and DB data flow
php > $apple = new AppBundle\Entity\Fruit('Apple');
php > $em->persist($apple);
php > $em->flush();

php > dump( $em->getRepository('AppBundle\Entity\Fluit')->findAll() );

# etc.

The problem here is that the dump() function shows nothing. I was expecting a colored command line output, however I tried this with echo or var_dump() and it works, but for objects mainly the output is dense and unreadable. In this direction the VarDumper Component documentation says:

By default, the output format and destination are selected based on your current PHP SAPI [...] * On the command line (CLI SAPI), the output is written on STDOUT. [...]

That's not working for me by default and I'm sure that PHP_SAPI is cli. Besides, I found a workaround setting debug.dump_destination to php://stderr, BUT:

# php interactive mode:
php > dump("test");
hp shell code on line 1: // <---- show the code line always
"test"

I don't like this output and neither change the config for this purpose only.

Any thoughts what happens with the dump() function and why it shows nothing? Thanks.

After migrating from 3.4 to 4.4, adding the missing file "package/debug.yaml" with php://stderr option fix the problem — sdespont
– sdespont, Commented Jan 28, 2021 at 8:20

β.εηοιτ.βε · Accepted Answer · 2019-03-26 23:52:16Z

6

For some reason, it looks like what you are trying to do is actually dependency injecting a specific handler into VarDumper

So the condition null === self::$handler is always false in the below reproduced snippet of that class code, and, thus, the dumper you expect for 'cli' === PHP_SAPI is not set.

public static function dump($var)
{

    if (null === self::$handler) {
    /**       ^--- this one       **/
        $cloner = new VarCloner();
        $dumper = 'cli' === PHP_SAPI ? new CliDumper() : new HtmlDumper();
        self::$handler = function ($var) use ($cloner, $dumper) {
            $dumper->dump($cloner->cloneVar($var));
        };
    }
    return call_user_func(self::$handler, $var);
}

source: Symfony/Component/VarDumper/VarDumper.php

Now, knowing this, your solution is as easy as just setting the handler of VarDumper back to null

Working code:

# bin/app_dev_cli.php
<?php
use Symfony\Component\VarDumper\VarDumper;

require __DIR__.'/../app/autoload.php';

$kernel = new AppKernel('dev', true);
$kernel->boot();

/** This line (plus the use statement on top) does what you want **/
VarDumper::setHandler(null);

// Useful global vars
$container = $kernel->getContainer();
$doctrine = $container->get('doctrine');
$em = $doctrine->getManager();

When run:

$ php -a
Interactive shell

php > require 'bin/app_dev_cli.php';
# bin/app_dev_cli.php 
php > dump('hi'); 
"hi"

edited Mar 26, 2019 at 23:52

answered May 10, 2017 at 22:50

β.εηοιτ.βε

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1 Comment

yceruto Over a year ago

Well, everything seems that the culprit is DebugBundle, who injects his handler first. In prod env VarDumper::setHandler(null) is needless :)

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