Framework - Bootloaders
Bootloaders are the central piece in Spiral Framework and your application. These objects are responsible for Container configuration, default configuration, etc.
Bootloaders are only executed once while loading your application. Since the app will stay in memory for long - you can add as much code to your bootloaders as you want. It will not cause any performance effect on runtime.
Simple Bootloader
You can create simple Bootloader by extending Spiral\Boot\Bootloader\Bootloader class:
namespace App\Bootloader;
use Spiral\Boot\Bootloader\Bootloader;
class MyBootloader extends Bootloader
{
}
Every Bootloader must be activated in your application kernel. Add the class reference into LOAD or APP lists of
your App\App class:
namespace App;
use Spiral\Framework\Kernel;
use App\Bootloader\RoutesBootloader;
use App\Bootloader\LoggingBootloader;
use App\Bootloader\MyBootloader;
class App extends Kernel
{
protected const LOAD = [
// ...
];
protected const APP = [
RoutesBootloader::class,
LoggingBootloader::class,
MyBootloader::class
];
}
Currently, your Bootloader doesn't do anything. A little bit later, we will add some functionality to it.
Available methods
Bootloaders provide two methods init and boot that are executed when the application is initialized.
Init
This method is executed first. It's recommended to set default values for configuration files. Modify configuration
files using special bootloader methods. Execute other logic that doesn't require reading configuration files
and doesn't depend on code execution in the init and boot methods of other bootloaders.
In this method, you can add initialization callbacks, configure container bindings if this does not require
access to the application configuration.
use Spiral\Boot\AbstractKernel;
use Spiral\Boot\Bootloader\Bootloader;
use Spiral\Boot\EnvironmentInterface;
use Spiral\Config\ConfiguratorInterface;
use Spiral\Queue\Config\QueueConfig;
final class QueueBootloader extends Bootloader
{
public function __construct(
private readonly ConfiguratorInterface $config
) {
}
public function init(
EnvironmentInterface $env,
AbstractKernel $kernel
): void {
$this->config->setDefaults(
QueueConfig::CONFIG,
[
'default' => $env->get('QUEUE_CONNECTION', 'sync'),
// ...
]
);
$kernel->booting(function () {
// ...
});
}
}
Boot
This method is executed after executing method init in all bootloaders. It can be used if you need the result
of the init methods in all bootloaders. For example, compiled configuration files.
use Spiral\Boot\Bootloader\Bootloader;
use Spiral\Config\ConfiguratorInterface;
use Spiral\Session\Config\SessionConfig;
final class SessionBootloader extends Bootloader
{
public function boot(
ConfiguratorInterface $config,
CookiesBootloader $cookies
): void {
$session = $config->getConfig(SessionConfig::CONFIG);
$cookies->whitelistCookie($session['cookie']);
}
}
Note
APPbootloader namespace is always loaded afterLOAD, keep domain-specific bootloaders in it.
Configuring Container
The most common use-case of bootloaders is to configure a DI container, for example, we might want to bind multiple implementations to their interfaces or construct some service.
We can use the method init or boot for these purposes. The method supports method injection, so we can request any services we
need:
namespace App\Bootloader;
use Spiral\Core\Container;
use App\MyClassInterface;
use App\MyClass;
use App\MyService;
class MyBootloader extends Bootloader
{
public function boot(Container $container): void
{
$container->bind(MyClassInterface::class, MyClass::class);
$container->bindSingleton(MyService::class, function(MyClass $myClass) {
return new MyService($myClass);
});
}
}
Bootloaders provide the ability to simplify container binding definition using constants BINDINGS and SINGLETONS.
namespace App\Bootloader;
use Spiral\Core\Container;
use App\MyClassInterface;
use App\MyClass;
use App\MyService;
class MyBootloader extends Bootloader
{
const BINDINGS = [
MyInterface::class => MyClass::class
];
public function boot(Container $container): void
{
$container->bindSingleton(MyService::class, function(MyClass $myClass) {
return new MyService($myClass);
});
}
}
You can also replace factory closures with factory methods:
namespace App\Bootloader;
use App\MyClassInterface;
use App\MyClass;
use App\MyService;
class MyBootloader extends Bootloader
{
const BINDINGS = [
MyInterface::class => MyClass::class
];
const SINGLETONS = [
MyService::class => [self::class, 'myService']
];
protected function myService(MyClass $myClass): MyService
{
return new MyService($myClass);
}
}
Configuring Application
Another common use case of bootloaders is to configure the framework before the application launch. For example, we can declare a new route for our application or module:
namespace App\Bootloader;
use Spiral\Router\RouterInterface;
use Spiral\Router\Target\Controller;
use Spiral\Router\Route;
class MyBootloader extends Bootloader
{
public function boot(RouterInterface $router): void
{
$router->setRoute(
'my-route',
new Route('/<action>', new Controller(MyController::class))
);
}
}
Note
In the exact same way, you can mount middleware, change tokenizer directories, and much more.
Depending on other Bootloaders
Some framework bootloaders can be used as a simple path to configure application settings. For example, we can
use Spiral\Bootloader\Http\HttpBootloader to add global PSR-15 middleware:
namespace App\Bootloader;
use Spiral\Bootloader\Http\HttpBootloader;
use App\Middleware\MyMiddleware;
class MyBootloader extends Bootloader
{
public function boot(HttpBootloader $http): void
{
$http->addMiddleware(MyMiddleware::class);
}
}
If you want to ensure that HttpBootloader has always been initiated before MyBootloader, use constant DEPENDENCIES:
namespace App\Bootloader;
use Spiral\Bootloader\Http\HttpBootloader;
use App\Middleware\MyMiddleware;
class MyBootloader extends Bootloader
{
const DEPENDENCIES = [
HttpBootloader::class
];
public function boot(HttpBootloader $http): void
{
$http->addMiddleware(MyMiddleware::class);
}
}
Note
that you are only able to use bootloaders to configure your components during the bootstrap phase (a.k.a. via another bootloader). The framework would not allow you to change any configuration value after component initialization.
Cascade bootloading
You can control the bootload process using Bootloader itself, simply request Spiral\Boot\BootloadManager:
namespace App\Bootloader;
use Spiral\Boot\Bootloader\Bootloader;
use Spiral\Boot\BootloadManager;
use Spiral\Bootloader\DebugBootloader;
use Spiral\Boot\EnvironmentInterface;
class AppBootloader extends Bootloader
{
public function boot(BootloadManager $bootloadManager, EnvironmentInterface $env): void
{
if ($env->get('DEBUG')) {
$bootloadManager->bootload([
DebugBootloader::class
]);
}
}
}