ODDIN - On Demand Dependency INjection

About

Sometimes coding is a pain. Your boss needs it now or simply you are bored writing all sugar again and again and ...

If you are using DI in your projects, you have to write property declarations and initialize them in constructors. You can use dependency container or define injectable constructor arguments. It depends on framework used. For of PHP7.4.0 only, 7.4.1 breaks functionality, php bug #78904.

class Foo {
    private Dependency1 $dep1;

    private Dependency2 $dep2;

    private Depencency3 $dep3;

    function __construct(Dependency1 $dep1, Dependency2 $dep2, Container $container)
    {
        $this->dep1 = $dep1;
        $this->dep2 = $dep2;
        $this->dep3 = $container->get(Dependency3::class);
    }

    public function bar() 
    {
        $this->dep1->doSomething();
    }

    protected function baz()
    {
        $this->dep2->doSomethind();
    }

    private function bye() 
    {
        $this->dep3->doSomething();
    }
}

With ODDIN you can skip constructor part. Just declare properties and access properties anytime you need. Keep in mind those properties becomes accessible from anywhere by magic __get method. Your preferred IDE will help you deal with that problem

class Foo {
    use InjectsOnDemand;

    private Dependency1 $dep1;

    private Dependency2 $dep2;

    private Depencency3 $dep3;

    /**
    * Foo constructor.
    * as of php7.4.1, we have to unset properties in constructor
    * https://bugs.php.net/bug.php?id=78904 
    */
    public function __construct() 
    {
        unset($this->dep1, $this->dep2, $this->dep3);
    }

    public function bar() 
    {
        $this->dep1->doSomething();
    }

    private function baz() 
    {
        $this->dep2->doSomething();
    }

    private function bye()
    {
        $this->dep3->doSomethind();
    }
}

How it works

PHP classes can have magic methods. The get magic method is invoked every time you want to use unset property. DIResolver uses parser to get dependency metadata from class or deprecated property annotations. InjectsOnDemand trait defines magic get method, which handles all our property requests. Once property is initialized by trait, magic method is not called again.

Pros

less coding
dependency instantiation on demand (lazy - not before constructor, if properly defined in DI container)

Cons

all properties becomes public ? all injectables are "public"
antipattern ? use it only for prototyping, clean the code later.

Purpouse

Cleaner controller classes, less resource demanding. But it's up to you, where you use ODDIN.

Known Issues

no code fixer yet

Quick start

You can use any DI container, which implements Psr\Container\ContainerInterface. For quick start, you can use Bootstrap class, which uses SmartContainer.

use BigBIT\DIBootstrap\Bootstrap;
use Psr\Container\ContainerInterface;

// custom bindings
$bindings = [
    FooInterface::class => function(ContainerInterface $container) {
        return new BarImplementation(
                $container->get(BazDependency::class)
            );
        }
];

$container = Bootstrap::getContainer($bindings);

$app = new SomeApp($container);

$app->run();

Other frameworks

You can request other frameworks support or write you own bootstrap based on Bootstrap class.

PHP-DI comparison

@todo

Cache Generator

Experimental implementation of cache generator was added. If your project has phpstan installed, it's recommended to install tracy/tracy as well. Oddin uses Psr\SimpleCache\CacheInterface implementations and Symfony as default.

Creating cache is not necessary, but recommended for production environments:

vendor/bin/oddin cache:injectables:create php-files -a oddin -a 0 -a cache

Arguments for cli commands are derived from adapter constructor.

Instantiating cache:

$bindings[CacheInterface::class] = function(ContainerInterface $container) {
    return new Psr16Cache(new PhpFilesAdapter('oddin', 0, dirname(__DIR__) . '/cache'));
};

@TODO - Code Fixer

Cli command for fixing code. It will remove class property annotations, declare properties and add constructor or getters and container to constructor.

andrzejenne / oddin

readme