Yii Injector

A dependency injection implementation based on autowiring and PSR-11 compatible dependency injection containers.

Features

Injects dependencies when calling functions and creating objects
Works with any dependency injection container (DIC) that is PSR-11 compatible
Accepts additional dependencies and arguments passed as array
Allows passing arguments by parameter name in the array
Resolves object type dependencies from the container and the passed array by parameter type declaration
Resolves variadic arguments i.e. function (MyClass ...$a)

About

Injector can automatically resolve and inject dependencies when calling functions and creating objects.

It therefore uses Reflection to analyze the parameters of the function to call, or the constructor of the class to instantiate and then tries to resolve all arguments by several strategies.

The main purpose is to find dependency objects - that is arguments of type object that are declared with a classname or an interface - in a (mandatory) PSR-11 compatible dependency injection container (DIC). The container must therefore use the class or interface name as ID.

In addition, an array with arguments can be passed that will also be scanned for matching dependencies. To make things really flexible (and not limited to objects), arguments in that array can optionally use a function parameter name as key. This way basically any callable can be invoked and any object be instantiated by the Injector even if it uses a mix of object dependencies and arguments of other types.

Basic Example

// A function to call
$fn = function (\App\Foo $a, \App\Bar $b, int $c) { /* ... */ };

// Arbitrary PSR-11 compatible object container
$container = new \some\di\Container([
    'App\Foo' => new Foo(), // will be used as $a
]);

// Prepare the injector
$injector = new Injector($container);

// Use the injector to call the function and resolve dependencies
$result = $injector->invoke($fn, [
    'c' => 15,  // will be used as $c
    new Bar(),  // will be used as $b
]);