Simple PHP Service Locator

ServiceLocator.php

<?php

/**
 * Class ServiceLocator
 *
 * Simple service locator class
 */
class ServiceLocator implements ServiceLocatorInterface
{

	/** @var array */
	protected $servicesDefinitions = [];

	/** @var Closure[]|mixed */
	protected $services = [];

	/**
	 * @param string $name
	 *
	 * @throw RuntimeException
	 *
	 * @return mixed
	 */
	public function get($name)
	{
		if (!is_string($name) || strlen($name) < 1) {
			throw new RuntimeException(
				"The service name is required."
			);
		}

		if (!$this->has($name)) {
			throw new RuntimeException(
				"The service {$name} has not been registered with the locator."
			);
		}

		$service   = $this->servicesDefinitions[$name]['definition'];
		$isFactory = $this->servicesDefinitions[$name]['isFactory'];

		if (is_object($service) && !is_callable($service)) {
			return $service;
		} elseif (!$isFactory && isset($this->services[$name])) {
			return $this->services[$name];
		} elseif (is_callable($service)) {
			$createdService = call_user_func_array($service, [$this]);

			if ($isFactory) {
				return $createdService;
			} else {
				$this->services[$name] = $createdService;

				return $this->services[$name];
			}
		}

		throw new RuntimeException(
			"The service {$name} has not been registered correctly."
		);
	}

	/**
	 * @param string        $name
	 * @param Closure|mixed $service
	 * @param bool          $isFactory
	 *
	 * @throw RuntimeException
	 *
	 * @return $this
	 */
	public function set($name, $service, $isFactory = false)
	{
		if (!is_string($name) || strlen($name) < 1) {
			throw new RuntimeException(
				"The service name is required."
			);
		}

		if (isset($this->servicesDefinitions[$name])) {
			$this->remove($name);
		}

		if (
			!is_object($service)
			&& !is_callable($service)
		) {
			$type = gettype($service);
			throw new RuntimeException(
				"Only objects and callable can be registered with the locator but '{$name}' has type '{$type}'."
			);
		}

		if (!is_bool($isFactory)) {
			$type = gettype($isFactory);
			throw new RuntimeException(
				"IsFactory parameter must be a boolean but '{$name}' has type '{$type}'."
			);
		}

		$this->servicesDefinitions[$name] = [
			'definition' => $service,
			'isFactory'  => $isFactory,
		];

		return $this;
	}

	/**
	 * @param string $name
	 *
	 * @return bool
	 */
	public function has($name)
	{
		return is_string($name)
		       && strlen($name) > 1
		       && isset($name, $this->servicesDefinitions)
		       && isset($this->servicesDefinitions[$name]['definition'])
		       && isset($this->servicesDefinitions[$name]['isFactory'])
			? true
			: false;
	}

	/**
	 * @param string $name
	 *
	 * @return $this
	 */
	public function remove($name)
	{
		if ($this->has($name)) {
			unset($this->servicesDefinitions[$name]);
			if (isset($this->services[$name])) {
				unset($this->services[$name]);
			}
		}

		return $this;
	}

	/**
	 * @return $this
	 */
	public function clear()
	{
		$this->services            = [];
		$this->servicesDefinitions = [];

		return $this;
	}

}

ServiceLocatorInterface.php

<?php

/**
 * Interface ServiceLocatorInterface
 */
interface ServiceLocatorInterface
{

	/**
	 * @param string $name
	 *
	 * @throw RuntimeException
	 *
	 * @return mixed
	 */
	public function get($name);

	/**
	 * @param string        $name
	 * @param Closure|mixed $service
	 * @param bool          $isFactory
	 *
	 * @throw RuntimeException
	 *
	 * @return $this
	 */
	public function set($name, $service, $isFactory = false);

	/**
	 * @param string $name
	 *
	 * @return bool
	 */
	public function has($name);

	/**
	 * @param string $name
	 *
	 * @return $this
	 */
	public function remove($name);

	/**
	 * @return $this
	 */
	public function clear();
}