The Bootloader classes responsible for pre-initialization of your application, use them to configure proper container bindings and environment initialization (i.e. http routes).
Make sure you read about Container and DI.
Ordinary, the application will require a lots of interfaces and aliases to be binded to their implementations, you can define bindings in your code using following constructions:
$this->container->bind(SomeInterface::class, SomeClass::class);
//or if concrete object needed
$this->container->bind(SomeInterface::class, function(...) {
return new SomeClass(...);
});
Example of binding usage:
public function indexAction(SomeInterface $some)
{
dump($some);
assert($some instanceof SomeClass);
}
Bootloaders make such definitions easier, faster and provide a way to merge multiple bindings into one group:
class SomeBootloader extends Bootloader
{
const BINDINGS = [
SomeInterface::class => SomeClass::class
];
const SINGLETONS = [
OtherInterface::class => [self::class, 'createOther']
];
protected function createOther(SomeInterface $class, ...)
{
return new OtherClass($class);
}
}
Note that you can make your factory methods private and protected, container will bypass this restriction.
The only thing we have to do now is to add such bootloader class into our application, modify constant LOAD in your App class.
const LOAD = [
//...
Bootloaders\SomeBootloader::class
];
You can enable bootloaders cache in your .env file to speed up application initialization a bit.
To load or execute custom code at moment of application initialization, set constant BOOT to true and define method boot:
class AppBootloader extends Bootloader
{
const BOOT = true;
const BINDIGNS = [
SomeInterface::class => SomeClass::class
];
const SINGLETONS = [
OtherInterface::class => [self::class, 'createOther']
];
//Automatically resolved by container
public function createOther(SomeInterface $class, ...)
{
return new OtherClass($class);
}
/**
* @param HttpDispatcher $http
*/
public function boot(HttpDispatcher $http)
{
$http->addRoute(new Route(
'route', 'route/<section:[a-z\-]*>',
'Vendor\Controllers\SomeController::action'
));
}
}
Cache is ignored for such bootloaders.
If you want to load your bootloader based on some condition use getBootloader() method of your core application:
public function indexAction()
{
$this->app->bootloader()->bootload([
\Vendor\Module\VendorBootloader::class
]);
}
Bootloaders can also be used to define shortcuts to your services:
class MyBootloader extends Bootloader
{
/**
* @return array
*/
const BINDINGINS = [
'someTable' => [self::class, 'someTable']
];
/**
* @param DatabaseManager $databases
*/
public function someTable(DatabaseManager $databases): Table
{
return $databases->database('default')->table('some');
}
}
Now you can use such table shortcut in your controllers or service:
public function indexAction()
{
dump($this->someTable);
}
You can treat shortcuts/[factory methods] as inline functions in C but in a context of active container scope.