03-php-di-3-3.md

layout	title	author	date
blogpost	PHP-DI 3.3 released	Matthieu Napoli	July 30rd 2013

I am happy to announce that PHP-DI version 3.3 has just been released.

The major new feature is the possibility to inject all dependencies of an existing instance.

But before jumping into that, did you know there's an article on how PHP-DI works.

Container::injectOn()

Read the full documentation here

$myObject = new MyClass();

$container->injectOn($myObject);

Now, $myObject has all its dependencies injected (setter injections and property injections).

It is basically the same as $myObject = $container->get('MyClass') except you create the instance.

Why?

Weird right? Well it's not supposed to be used everywhere.

Hopefully, that will help a lot to integrate PHP-DI with other frameworks:

• MVC frameworks (Symfony 2, Zend Framework 2, …): inject dependencies of the controller, in the controller itself.
• Tests (PHPUnit, …): inject tools in your test class, for example a logger, a timer (for performance test), the entity manager (for integration tests), …

Example:

class MyController {
    public function __construct() {
        // get container ...
        $container->injectOn($this);
    }
}

Of course, the preferred method is still to use $container->get(). But sometimes you can't get to the root of the framework to intercept the creation of your objects (I'm looking at you most MVC frameworks, PHPUnit & …)

Good to know

PHP-DI will not perform any constructor injection. But of course most of the time you'll be using that feature is when you can't/don't want to use the constructor for getting your dependencies.

Change log

Except this feature, 3.3 contains an optimization for definition resolution and a bugfix for a rare situation.

Read all the changes and their authors in the change log.