Accessing session from TWIG template

I've searched a lot on the net how to access the global $_SESSION array from TWIG template and found this: {{app.session.get('index')}}, but when I'm calling it, it returns an empty string. I have a $_SESSION['filter']['accounts'] and I'm getting this error when calling {{app.session.get('filter').accounts}}: Item "accounts" for "" does not exist. What I'm doing wrong?

{{app.session}} refers to the Session object and not the $_SESSION array. I don't think the $_SESSION array is accessible unless you explicitly pass it to every Twig template or if you do an extension that makes it available.

Symfony2 is object-oriented, so you should use the Session object to set session attributes and not rely on the array. The Session object will abstract this stuff away from you so it is easier to, say, store the session in a database because storing the session variable is hidden from you.

So, set your attribute in the session and retrieve the value in your twig template by using the Session object.

// In a controller
$session = $this->get('session');
$session->set('filter', array(
    'accounts' => 'value',
));

// In Twig
{% set filter = app.session.get('filter') %}
{% set account-filter = filter['accounts'] %}

Hope this helps.

Regards,
Matt

Setup twig

$twig = new Twig_Environment(...);    
$twig->addGlobal('session', $_SESSION);

Then within your template access session values for example

$_SESSION['username'] in php file Will be equivalent to {{ session.username }} in your twig template

A simple trick is to define the $_SESSION array as a global variable. For that, edit the core.php file in the extension folder by adding this function :

public function getGlobals() {
    return array(
        'session'   => $_SESSION,
    ) ;
}

Then, you'll be able to acces any session variable as :

{{ session.username }}

if you want to access to

$_SESSION['username']

The way to access a session variable in Twig is:

{{ app.session.get('name_variable') }}

I found that the cleanest way to do this is to create a custom TwigExtension and override its getGlobals() method. Rather than using $_SESSION, it's also better to use Symfony's Session class since it handles automatically starting/stopping the session.

I've got the following extension in /src/AppBundle/Twig/AppExtension.php:

<?php    
namespace AppBundle\Twig;

use Symfony\Component\HttpFoundation\Session\Session;

class AppExtension extends \Twig_Extension {

	public function getGlobals() {
		$session = new Session();
		return array(
			'session' => $session->all(),
		);
	}

	public function getName() {
		return 'app_extension';
	}
}

Then add this in /app/config/services.yml:

services:
    app.twig_extension:
        class: AppBundle\Twig\AppExtension
        public: false
        tags:
            - { name: twig.extension }

Then the session can be accessed from any view using:

{{ session.my_variable }}