DI Container

1. # Application DI Container
2. # IoC Resolver
3. # Resolving

#Application DI Container

Register a class to the DI Container.

// singlton and alias are both optional arguments
$singleton = true;
$alias = 'my.class';

\TypeRocket\Core\Injector::register(\MyNamespace\MyClass::class, function () {
    $api_key = 'sdfjd83mvbfy92kf';

    return new \MyNamespace\MyClass($api_key);
}, $singleton, $alias);

Get an instance from the DI container.

// by class name
$obj = \TypeRocket\Core\Injector::resolve(\MyNamespace\MyClass::class);

// by alias
$obj = \TypeRocket\Core\Injector::resolve('my.class');

Using helper.

$obj = tr_container(\MyNamespace\MyClass::class)

#IoC Resolver

The inversion of control resolver automatically tries to instantiate a class with its dependencies. The Resolver object will look at a class' constructor and automatically inject its dependencies.

#Resolving

The Resolver classes method resolve() take one argument:

1. $class - The name of the class.

The resolve() method will check the class' constructor and try to resolve the dependencies by looking at the type hints in the constructor. If a constructor argument has a default value and no type-hint the default value will be used.

// Classes
class Cheese {
    public $type;

    function __construct( $type = 'cheddar' ) {
        $this->type = $type;
    }
}

class Pizza {
    public $cheese;

    function __construct( \Cheese $cheese ) {
        $this->cheese = $cheese;
    }
}

// Resolver
$resolver = new \TypeRocket\Core\Resolver();
$pizza = $resolver->resolve('Pizza');
echo $pizza->cheese->type;

Will output,

cheddar

Note: If one of the classes is located in the DI Container then the DI Container will be used for resolution of that class.