feat(flextype): new Flextype core #199

New Methods:

- `app` - Returns Flextype Application.
- `container` - Returns Flextype Application Container.

BREAKING CHANGES

`container` method only returns Flextype Application Container based on PHP-DI
documentation: https://php-di.org/doc/container.html

src/flextype/Foundation/Flextype.php

@@ -9,25 +9,11 @@ declare(strict_types=1);
 
 namespace Flextype\Foundation;
 
-use Exception;
 use DI\Bridge\Slim\Bridge;
 use DI\Container;
-use Slim\App;
-use Slim\Middleware\ContentLengthMiddleware;
-use Slim\Middleware\OutputBufferingMiddleware;
-use Slim\Middleware\RoutingMiddleware;
-use Slim\Psr7\Factory\StreamFactory;
-use Atomastic\Csrf\Csrf;
-use Atomastic\Registry\Registry;
-use Atomastic\Session\Session;
-use Cocur\Slugify\Slugify;
-use DateTimeZone;
-use Flextype\Foundation\Actions;
-use Psr\Http\Message\ResponseInterface as Response;
-use Psr\Http\Message\ServerRequestInterface as Request;
+use Exception;
 use Psr\Container\ContainerInterface;
-
-use function is_null;
+use Slim\App;
 
 final class Flextype
 {
@@ -37,16 +23,21 @@ final class Flextype
     public const VERSION = '0.9.16';
 
     /**
-     * The Flextype's instance is stored in a static field. This field is an
-     * array, because we'll allow our Flextype to have subclasses. Each item in
-     * this array will be an instance of a specific Flextype's subclass.
+     * The Flextype Application instances.
      *
      * @var array
      */
     private static array $instances = [];
 
-    private App $app;
-    private Container $container;
+    /**
+     * The Flextype Application.
+     */
+    private static App $app;
+
+    /**
+     * The Flextype Application Container.
+     */
+    private static Container $container;
 
     /**
      * Flextype should not be cloneable.
@@ -65,29 +56,49 @@ final class Flextype
     }
 
     /**
-     * Flextype construct
+     * Flextype construct.
      */
-    protected function __construct(ContainerInterface $container = null)
+    protected function __construct(?ContainerInterface $container = null)
     {
-        $this->app       = Bridge::create($container);
-        $this->container = $this->app->getContainer();
-    }
+        // Set Application with PHP-DI Bridge
+        self::$app = Bridge::create($container);
 
-    public function app() 
-    {
-        return $this->app;
+        // Set Application Container
+        self::$container = self::$app->getContainer();
     }
 
-    public function container() 
-    {
-        return $this->container;
-    }
-
-
     /**
-     * Returns Flextype Instance
+     * Get Flextype Application.
+     *
+     * @return App Returns Flextype Application.
+     *
+     * @access public
      */
-    public static function getInstance(ContainerInterface $container = null): Flextype
+    public function app(): App
+    {
+        return self::$app;
+    }
+
+    /**
+     * Get Flextype Application Container.
+     *
+     * @return Flextype Returns Flextype Application Container.
+     *
+     * @access public
+     */
+    public function container(): Container
+    {
+        return self::$container;
+    }
+
+    /**
+     * Returns Flextype Instance.
+     *
+     * @return Flextype Returns the current Flextype Instance.
+     *
+     * @access public
+     */
+    public static function getInstance(?ContainerInterface $container = null): Flextype
     {
         $cls = static::class;
         if (! isset(self::$instances[$cls])) {
@@ -98,7 +109,11 @@ final class Flextype
     }
 
     /**
-     * Returns the current Flextype version
+     * Get the current Flextype version.
+     *
+     * @return string Returns the current Flextype version.
+     *
+     * @access public
      */
     public function getVersion(): string
     {