From 166465ec7a7da381a7379b8b37886996c5bc9b92 Mon Sep 17 00:00:00 2001
From: Klimov Paul <klimov.paul@gmail.com>
Date: Tue, 17 Jun 2014 18:00:22 +0300
Subject: [PATCH] `MigrationInterface` extracted

---
 .../controllers/BaseMigrateController.php     |  3 +-
 framework/db/Migration.php                    |  3 +-
 framework/db/MigrationInterface.php           | 35 +++++++++++++++++++
 3 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 framework/db/MigrationInterface.php

diff --git a/framework/console/controllers/BaseMigrateController.php b/framework/console/controllers/BaseMigrateController.php
index 1acd76df8d..85c1e6e475 100644
--- a/framework/console/controllers/BaseMigrateController.php
+++ b/framework/console/controllers/BaseMigrateController.php
@@ -16,7 +16,6 @@ use yii\helpers\FileHelper;
  * BaseMigrateController is base class for migrate controllers.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
- * @author Klimov Paul <klimov@zfort.com>
  * @since 2.0
  */
 abstract class BaseMigrateController extends Controller
@@ -528,7 +527,7 @@ abstract class BaseMigrateController extends Controller
     /**
      * Creates a new migration instance.
      * @param string $class the migration class name
-     * @return \yii\db\Migration the migration instance
+     * @return \yii\db\MigrationInterface the migration instance
      */
     protected function createMigration($class)
     {
diff --git a/framework/db/Migration.php b/framework/db/Migration.php
index 049c4f695e..3533f2489d 100644
--- a/framework/db/Migration.php
+++ b/framework/db/Migration.php
@@ -8,6 +8,7 @@
 namespace yii\db;
 
 use yii\di\Instance;
+use \yii\base\Component;
 
 /**
  * Migration is the base class for representing a database migration.
@@ -35,7 +36,7 @@ use yii\di\Instance;
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class Migration extends \yii\base\Component
+class Migration extends Component implements MigrationInterface
 {
     /**
      * @var Connection|string the DB connection object or the application component ID of the DB connection
diff --git a/framework/db/MigrationInterface.php b/framework/db/MigrationInterface.php
new file mode 100644
index 0000000000..7f69c6499f
--- /dev/null
+++ b/framework/db/MigrationInterface.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db;
+
+/**
+ * The MigrationInterface defines the minimum set of methods to be implemented by a database migration.
+ *
+ * Each migration class should provide the [[up()]] method containing the logic for "upgrading" the database
+ * and the [[down()]] method for the "downgrading" logic.
+ *
+ * @author Klimov Paul <klimov@zfort.com>
+ * @since 2.0
+ */
+interface MigrationInterface
+{
+    /**
+     * This method contains the logic to be executed when applying this migration.
+     * @return boolean return a false value to indicate the migration fails
+     * and should not proceed further. All other return values mean the migration succeeds.
+     */
+    public function up();
+
+    /**
+     * This method contains the logic to be executed when removing this migration.
+     * The default implementation throws an exception indicating the migration cannot be removed.
+     * @return boolean return a false value to indicate the migration fails
+     * and should not proceed further. All other return values mean the migration succeeds.
+     */
+    public function down();
+} 
\ No newline at end of file