Service

Overview:

Service is a lightweight service container supporting singleton and factory registrations.

Use Service to register singleton or factory-style dependencies and resolve them lazily through a lightweight container.

Public API:

• Service::register($serviceName, $factory) registers a singleton factory.
• Service::registerFactory($serviceName, $factory) registers a non-singleton factory.
• Service::serviceName(...$params) resolves the service via __callStatic.

Example:

Service::register('db', function () {
  return SQL::using('default');
});
$db = Service::db();

The Service module sports a service locator and a factory container.

This module permits the user to register and retrieve a service manager instance, one (singleton) or multiple times.

Register a service container (singleton)

---

You can use the register method to add a service container that will be called and instantiated a single time.

class Greeter {
  protected $name;
  public function __construct($name){ $this->name = $name; }
  public function hi(){ echo "Hello, {$this->name}"; }
}

Service::register('greeter',function() {
  return new Greeter("Friend");
});

You can now call the greeter service with the Service::<service_name> pattern :

echo Service::greeter()->hi();
// Hello, Friend

Once instantiated the Service register holds the returned value from the passed callback and returns that every time the service is accessed.

Passing arguments to the service init callback

---

In the precedent example the Friend parameter was hard-coded in the init callback.

However if you want to let the user pass the init arguments the first time the service is invoked, you can :

Service::register('greeter',function($whoami) {
  return new Greeter($whoami);
});

echo Service::greeter("John")->hi();
// Hello, John
echo Service::greeter("Marie")->hi();
// Hello, John
echo Service::greeter()->hi();
// Hello, John

Register a service factory

---

You can use the registerFactory method to add a service container that will be called and instantiated every time.

Service::registerFactory('envelope',function($message) {
  return (object)[
    "type" => "envelope",
    "data" => [
      "body"   => $message,
      "length" => strlen($message),
    ],
  ];
});

Now, every time you call Service::envelope the init callback will be invoked

$a = Service::envelope("This is a test");
$b = Service::envelope("It's over 9000!!!!");

echo json_encode([$a,$b], JSON_PRETTY_PRINT);

[
    {
        "type": "envelope",
        "data": {
            "body": "This is a test",
            "length": 14
        }
    },
    {
        "type": "envelope",
        "data": {
            "body": "It's over 9000!!!!",
            "length": 18
        }
    }
]

The Service module sports a service locator and a factory container.

This module permits the user to register and retrieve a service manager instance, one (singleton) or multiple times.