Added ValidableQuestion

Question/ValidableQuestion.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Symfony\Component\Console\Question;
+
+/**
+ * Represents a Validable question.
+ *
+ */
+class ValidableQuestion extends Question{
+
+    private $rules;
+
+    public function __construct($question, array $rules, $default = null)
+    {
+        parent::__construct($question, (bool) $default);
+
+        $this->rules = $rules;
+        $this->setValidator($this->validate());
+    }
+
+    private function validate()
+    {
+        $rules = $this->rules;
+
+        return function ($answer) use ($rules) {
+            foreach ($rules as $rule){
+                $answer = $this->validateRule($rule, $answer);
+            }
+            return $answer;
+        };
+    }
+
+    private function validateRule($rule, $answer)
+    {
+        if ($rule == 'required'){
+            if (!$answer) {
+                throw new \InvalidArgumentException(
+                    'Come on, give me something!'
+                );
+            }
+        }
+
+        if ($rule == 'numeric'){
+            if (!is_numeric($answer)) {
+                throw new \RuntimeException(
+                    'Please, enter a num3r1c value'
+                );
+            }
+        }
+
+        return $answer;
+    }
+}