Magento 2: Registry Object

In Magento 1, it was possible to register a global variable with the static registry method.

Mage::register('some_var', 'some value');
var_dump(Mage::registry('some_var'));

Many extensions, include core Magento extensions, ended up using this from controller action methods to pass variables into the views.

While its future is uncertain (not marked explicatly supported via an @api, but not marked @deprecated) Magento 2 does have a similar registry object that should help easy the transition for extensions. The class is MagentoFrameworkRegistry, and you can inject it in any constructor.

public function __construct(//... 
    \Magento\Framework\Registry $registry,
    //...
)
{
    //...
    $this->registry     = $registry;
    //...
}

and then set variables with

$this->registry->register('test_var', 'this is a test!');

and fetch those variables back (even from a differnt object – MagentoFrameworkRegistry is a shared/singleton object)

echo $this->registry->registry('test_var');

This probably violates all sorts of principles of object oriented development – but for folks who need to ship software that people use it can be a convient shortcut – just don’t forget to mark the code for future refactoring.

Confused by the dependency injection? Read the Magento Object Manager series and demystify dependency injection in Magento 2 once and for all