Accessing the AppKernel environment variable in symfony 2

Question

I'm Using symfony 2 and we have 2 configurations, dev and prod. I need to know if I can find out which one im using inside an Entity or Model.

I'm looking for something similar to this code found in AppKernel.php:

$this->getEnvironment()

If I could load the Kernel to call this that would be great but I can't find a way to do this. After looking into this it appears that symfony events may return the Kernel but I don't know how or where to capture these events so that I can call getKernel() on them. http://symfony.com/doc/current/book/internals.html

For example, they list this example:

use Symfony\Component\HttpKernel\Event\FilterControllerEvent;

public function onKernelController(FilterControllerEvent $event)
{
    $controller = $event->getController();
    // ...

    // the controller can be changed to any PHP callable
    $event->setController($controller);
}

Its unclear to me where to put this block of code. It seems to me that it should go in the Kernel, and if I had the Kernel I wouldn't be having this problem.

My question is, is there an easy way for me to determine if I'm in 'dev' or 'prod' as set in the Kernel, from a Service or Model. Thanks

score 53 · Accepted Answer · answered May 17 '12 at 19:00

The default entity classes generated by the console don't inherit anything. This means they aren't "ContainerAware" in any way.

And generally speaking, I don't think they should be. I supposed it depends on what you're doing but you could handle this with some basic dependency injection

In a controller:

$entity = new \Your\Bundle\Entity\Foo(
  $this->container->get( 'kernel' )->getEnvironment()
);

And then in src/Your/Bundle/Entity/Foo.php

private $env;

public function __construct( $env=null )
{
  $this->env = $env;
}

Would this work for you?

P.S. The event listener you posted about is for Controllers - not for arbitrary classes.

I'm using Symfony 2.6 and I had to do: $kernel = $this->container->get( 'kernel' ); — Dominick, May 14 '15 at 19:57

Francesco Casula · Answer 2 · 2015-05-05T10:23:42.727

It's also possible to get that as a parameter. If you take a look at the \Symfony\Component\HttpKernel\Kernel class you'll find a getKernelParameters() method that exposes all the kernel parameters.

/**
 * Returns the kernel parameters.
 *
 * @return array An array of kernel parameters
 */
protected function getKernelParameters()
{
    $bundles = array();
    foreach ($this->bundles as $name => $bundle) {
        $bundles[$name] = get_class($bundle);
    }

    return array_merge(
        array(
            'kernel.root_dir' => realpath($this->rootDir) ?: $this->rootDir,
            'kernel.environment' => $this->environment,
            'kernel.debug' => $this->debug,
            'kernel.name' => $this->name,
            'kernel.cache_dir' => realpath($this->getCacheDir()) ?: $this->getCacheDir(),
            'kernel.logs_dir' => realpath($this->getLogDir()) ?: $this->getLogDir(),
            'kernel.bundles' => $bundles,
            'kernel.charset' => $this->getCharset(),
            'kernel.container_class' => $this->getContainerClass(),
        ),
        $this->getEnvParameters()
    );
}

So in a services.yml file you can get the environment with %kernel.environment% whilst in a container aware class you can get it by doing:

$this->getContainer()->getParameter('kernel.environment');

see Kernel.php class on github

I would recommend to call the `parent::getKernelParameters()` method in order to be sure not to forget any parameter if one is added in the next releases of symfony :) `return array_merge(parent::getKernelParameters(), array(...));` — Flo Schild, Dec 23 '16 at 10:51

score 3 · Answer 3 · answered Oct 04 '16 at 09:42

3

Of course there is the quick and dirty way of globals...

function quickAndDirty() {
   global $kernel;

   if ($kernel->getEnvironment() == 'dev') {
      // we're in dev mode
   }
}

Its bad and evil and you should wash yourself after using it, but in the case of a large existing codebase that you perhaps inherited, it saves a potential refactoring nightmare.

Of course, whether you can live with yourself after using such a method, is up to you ;)

answered Oct 04 '16 at 09:42

Steve Childs

1,832
2
20
26

5

Please, never do this – Dan Nov 01 '18 at 13:07
@Dan: what's wrong with this specific use of globals? If not in a container-aware class it can still be entirely necessary to know whether the site is running in production or not. (At [PHP global or $GLOBALS](https://stackoverflow.com/questions/3573847/php-global-or-globals) they suggest that using `$GLOBALS['kernel']` instead avoids the ambiguity over scope that the code here can create.) – GKFX Mar 04 '19 at 10:38
Well, to answer my own question, it turns out that the first thing wrong with this is that `$GLOBALS['kernel']` in production is an instance of AppCache on Symfony 3.4.22, so this crashes with `Attempted to call an undefined method named "getEnvironment" of class "AppCache"`. – GKFX Mar 04 '19 at 10:51

score 2 · Answer 4 · answered Apr 04 '19 at 21:58

(Note: this works on Symfony 3.x, not sure about 4.x)

You can inject %kernel.environment% straight into your service:

    my_service:
        class: My\Foo
        properties:
            env: '%kernel.environment%'

Then in your service class:


class Foo {

    $env;
    ...
    function someFunction()
    {
        if($this->env === 'dev') {
            // do some dev stuff
        }
        else {
            // do some prod stuff
        }
    }
}

This has the advantage that if you are unit testing you don't need the container.

If you don't like property injection, you can use constructor or setter injection.

Accessing the AppKernel environment variable in symfony 2

4 Answers4

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