Add up() and down() method to table

Author: markusjwetzel

README.md

@@ -76,6 +76,7 @@ Furthermore for each of the migration specific names that we declared in the mig
 
 use Illuminate\Database\Schema\Blueprint;
 use ProAI\SuperMigrations\Table;
+use Illuminate\Support\Facades\DB;
 
 class UserTable extends Table
 {
@@ -86,20 +87,29 @@ class UserTable extends Table
      */
     public function create()
     {
-        // migrations up
+        // These statements will be only executed if direction of migrations is up
         $this->upSchema()->create(function (Blueprint $table) {
             $table->increments('id');
             $table->timestamps();
         });
 
-        // migrations down
+        $this->up(function($tableName) {
+            DB::raw('ALTER TABLE `'.$tableName.'` ADD `client_id` BINARY(16)');
+        });
+
+
+        // These statements will be only executed if direction of migrations is down
         $this->downSchema()->dropIfExists();
+
+        $this->down(function($tableName) {
+            // some code
+        });
     }
 }
 
 ```
 
-We use `$this->upSchema()` and `$this->downSchema()` to define the up and down schema. These methods return a `ProAI\SuperMigrations\Builder` instance that is similar to the Laravel database schema builder (see [Laravel docs](https://laravel.com/docs/5.3/migrations)). The only difference is that you don't need the tablename as first argument, because the tablename is already known.
+We use `$this->upSchema()` and `$this->downSchema()` to define the up and down schema. These methods return a `ProAI\SuperMigrations\Builder` instance that is similar to the Laravel database schema builder (see [Laravel docs](https://laravel.com/docs/5.3/migrations)). The only difference is that you don't need the tablename as first argument, because the tablename is already known. Furthermore we use `$this->up(...)` and `$this->down(...)` to insert custom code like raw DB statements.
 
 ### Generator Command
 

src/Table.php

@@ -6,6 +6,13 @@
 
 abstract class Table
 {
+    /**
+     * The table associated with the schema.
+     *
+     * @var string
+     */
+    private $table;
+
     /**
      * Direction of the migration (up or down).
      *
@@ -28,13 +35,40 @@ abstract class Table
      */
     public function __construct($table, $direction)
     {
+        $this->table = $table;
         $this->direction = $direction;
 
         $this->schema = new Builder($table);
     }
 
     /**
-     * Run the migrations.
+     * Execute a command if migration direction is up.
+     *
+     * @param  $command  \Closure
+     * @return void
+     */
+    protected function up($command)
+    {
+        if ($this->direction === 'up') {
+            $command($this->table);
+        }
+    }
+
+    /**
+     * Execute a command if migration direction is down.
+     *
+     * @param  $command  \Closure
+     * @return void
+     */
+    protected function down($command)
+    {
+        if ($this->direction === 'down') {
+            $command($this->table);
+        }
+    }
+
+    /**
+     * Get a schema builder instance if migration direction is up.
      *
      * @return \ProAI\SuperMigrations\Builder
      */
@@ -50,9 +84,9 @@ protected function upSchema()
     }
 
     /**
-     * Reverse the migrations.
+     * Get a schema builder instance if migration direction is up.
      *
-     * @return void
+     * @return \ProAI\SuperMigrations\Builder
      */
     protected function downSchema()
     {