Container, Factories and the dependency injector

PSR Container built for MaplePHP framework

Container, Factories and dependency injectors will help to make your PHP code more maintainable, flexible, and testable by reducing coupling between objects and centralizing the management of dependencies.

• Container
• Factory
• Dependency injector
• Event handler

Container

Containers allowing you to easily create and retrieve objects that are needed throughout your application.

use MaplePHP\Container\Container;

$container = new Container();

// You can set mixed values in the container
$container->set("hasEmail", true);

$hasEmail = $container->get("hasEmail")->get();
var_dump($hasEmail); // Result in: (bool) true

If the constructor of "YourClass" contains unresolved class arguments, the dependency injector will attempt to automatically locate them for you. Read more under the headline dependency injector.

Factory

Factories can be used to create new instances of objects, rather than instantiating them directly in your code.

$container->factory("factoryKey", function() {
    $a = new TestClassA();
    $b = new TestClassB();
    return new TestClassC($a, $b);
});
echo $container->get("factoryKey"); // Will return TestClassC

Dependency injector

Dependency injection is a technique for managing dependencies between objects in an application. Instead of creating objects directly in your code, you can pass them in as dependencies when you instantiate an object. This makes your code more modular and easier to test, as you can easily swap out dependencies for mock objects or other implementations.

You can use the Dependency injector just like create any other container, as long as you dont add arguments or try to access method, if you do that then it will automatically disable Dependency injector. It is design like this becouse it will load in all class reclusive into endlessly.

Take a look at this example

use MaplePHP\Container\Container;
use MaplePHP\Container\Autowire;
use App\Services\MailService;

$container = new Container();
$container->set("MailService", new Autowire(MailService::class));

// This will return "MailService" with all dependencies resolved on constructor
$mailService = $container->get("MailService")->get();
echo $mailService->send();

Event handler

Initiate

use MaplePHP\Container\EventHandler;

Example 1 - (Callable)

$logger = new EventHandler();
$logger->addHandler(new Logger());
$logger->addEvent(function() {
    var_dump("Executed in conjunction with logger every method");
    // You could add a mail function that will send log message to you,
});
echo $logger->error("A error message to log");
// Will log message AND execute the event

Example 2 - (Bind to method)

$logger = new EventHandler();
$logger->addHandler(new Logger(), ["emergency", "alert", "critical"]);
$logger->addEvent(function() {
    var_dump("Executed in conjunction with logger event method");
    // You could add a mail function that will send log message to you,
});
echo $logger->error("A error message to log");
// Will only log message
echo $logger->alert("A error message to log");
// Will log message AND execute the event

Example 3 - (Add service to handler)

Set the namespace to the EventInterface.

use MaplePHP\Container\Interfaces\EventInterface;

Then extend a class with implements to the interface EventInterface and add the method resolve to that class. I am using a "Anonymous Function" bellow as an example just to show that EventInterface is required, you can use a regular class.

$callableFunction = new class implements EventInterface {

    public function someMethod(string $what): string
    {
        return "Hello {$what}!";
    }

    // Resolve method will be executed in conjunction 
    // with logger event method
    public function resolve(): void
    {
        var_dump($this->someMethod("world"));
    }
};

$logger = new EventHandler();
$logger->addHandler(new Logger(), ["emergency", "alert", "critical"]);
$logger->addEvent(function() {
    var_dump("Executed in conjunction with logger event method");
    // You could add a mail function that will send log message to you,
});
echo $logger->error("A error message to log");
// Will only log message
echo $logger->alert("A error message to log");
// Will log message AND execute the event