Added GridFSFilesystem

Author: creocoder

src/GridFSFilesystem.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * @link https://github.com/creocoder/yii2-flysystem
+ * @copyright Copyright (c) 2015 Alexander Kochetov
+ * @license http://opensource.org/licenses/BSD-3-Clause
+ */
+
+namespace creocoder\flysystem;
+
+use League\Flysystem\GridFS\GridFSAdapter;
+use MongoClient;
+use Yii;
+use yii\base\InvalidConfigException;
+
+/**
+ * GridFSFilesystem
+ *
+ * @author Alexander Kochetov <[email protected]>
+ */
+class GridFSFilesystem extends Filesystem
+{
+    /**
+     * @var string
+     */
+    public $server;
+    /**
+     * @var string
+     */
+    public $database;
+
+    /**
+     * @inheritdoc
+     */
+    public function init()
+    {
+        if ($this->server === null) {
+            throw new InvalidConfigException('The "server" property must be set.');
+        }
+
+        if ($this->database === null) {
+            throw new InvalidConfigException('The "database" property must be set.');
+        }
+
+        parent::init();
+    }
+
+    /**
+     * @return GridFSAdapter
+     */
+    protected function prepareAdapter()
+    {
+        return new GridFSAdapter((new MongoClient($this->server))->selectDB($this->database)->getGridFS());
+    }
+}