opxcore / container
The OpxCore dependency injection container.
Requires
- php: ^7.4
- opxcore/container-interface: ^1.0.1
Requires (Dev)
- phpunit/phpunit: ^9.5.0
README
Introduction
The dependency injection container is a powerful tool for managing class dependencies and performing dependency injection. Class dependencies are "injected" into the class via the constructor and resolved by the container.
Example:
class Controller { protected Repository $repository; public function __construct(Repository $repository) { $this->repository = $repository; } }
Calling $container->make(Controller::class)
would be equal to new Controller(new Repository)
. This amazing feature
resolves all dependency injections automatically with zero-config. For this example if
Repository
have its own dependency, it will be resolved the same.
Installing
composer require opxcore/container
Creating
You can create a container several ways:
$container = Container::setContainer(new Container);
or
$container = Container::getContainer();
In all of this cases Container::getContainer()
will always return the same container instance.
If you want to create and handle a container (or several containers) by yourself just use
$container = new Container
and handle this container instance as you want.
Registering a binding with the container
Basic binding to container looks like:
$container->bind($abstract, $concrete, $parameters);
$abstract
is a string containing class name or shorthand for a name to be resolved.
$concrete
is a string containing class name or callable
returning object for a name to be resolved to. Container
instance and parameters will be passed to callable during resolving.
$parameters
is an array or callable returning array with parameters used for resolving (see below). Default value
is null
means no parameters will be bound.
Examples:
Simple usage
$container->bind('logger', Logger::class); // New instance of Logger with resolved dependencies will be retuened. $logger = $container->make('logger');
Binding interfaces to its realizations
We have Controller
class what depends on some RepositoryInterface
and FileRepository
implementing it:
class Controller { protected RepositoryInterface $repository; public function __construct(RepositoryInterface $repository) { $this->repository = $repository; } }
class FileRepository implements RepositoryInterface { protected string $path; public function __construct(string $path) { $this->path = $path; } }
Now we bind FileRepository::class
to RepositoryInterface::class
so when some class depends on RepositoryInterface
it will be resolved to FileRepository
and path
argument will be passed into with specified value.
$container->bind(RepositoryInterface::class, FileRepository::class, ['path'=>'/data/storage']); $controller = $container->make(Controller::class);
Binding parameters
You can bind parameters into the container fo resolving. It can be used as primitives binding or class binding:
// When FileRepository dependencies would be resolving, given value would be passed to `path` attribute. $container->bindParameters(FileRepository::class, ['path' => '/data/storage']); // When Controller would be resolved a FileRepository would be given as RepositoryInterface dependency. $container->bindParameters(Controller::class, [RepositoryInterface::class => FileRepository::class]);
Singleton
The singleton method binds a class or interface into the container that should be resolved once. First time it will be resolved and stored in the container, so other times the same object instance will be returned on subsequent calls into the container.
$container->singleton(RepositoryInterface::class, FileRepository::class, ['path'=>'/data/storage']); // Each time when RepositoryInterface needs to be resolved // the same instance of FileRepository would be given. $repository = $container->make(RepositoryInterface::class);
Alias
Alias is another name for resolving.
$container->singleton(RepositoryInterface::class, FileRepository::class, ['path'=>'/data/storage']); $container->alias(RepositoryInterface::class, 'repo'); // This would return FileRepository instance. $container->make('repo');
Instance
You can register any object or value into the container.
$container->instance('path', '/data/storage'); // '/data/storage' would be returned $container->make('path'); $container->instance(RepositoryInterface::class, new FileRepository('/data/storage')); // FileRepository would be returned $container->make(RepositoryInterface::class);
Resolving
When resolving some name, you can pass parameters to make()
function to attach it for resolving subject.
$container->bind(RepositoryInterface::class, FileRepository::class); $container->make(RepositoryInterface::class, ['path'=>'/data/storage']);
Sequence of making subject
When resolving some subject, the container checks for registered aliases first, checks for registered instances and resolves using reflections.