[Form] Add default validation to TextType field (and related)

src/Symfony/Component/Form/Extension/Core/DataTransformer/ValueToStringTransformer.php

@@ -0,0 +1,67 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataTransformer;
+
+use Symfony\Component\Form\DataTransformerInterface;
+use Symfony\Component\Form\Exception\UnexpectedTypeException;
+
+/**
+ * Transforms between a given value and a string.
+ *
+ * @author Joseph Bielawski <stloyd@gmail.com>
+ */
+class ValueToStringTransformer implements DataTransformerInterface
+{
+    /**
+     * Transforms a value into a string.
+     *
+     * @param  mixed  $value   Mixed value.
+     *
+     * @return string          String value.
+     *
+     * @throws UnexpectedTypeException if the given value is not a string or number
+     */
+    public function transform($value)
+    {
+        if (null === $value) {
+            return '';
+        }
+
+        if (!is_string($value) && !is_numeric($value)) {
+            throw new UnexpectedTypeException($value, 'string or number');
+        }
+
+        return $value;
+    }
+
+    /**
+     * Transforms a value into a string.
+     *
+     * @param  string $value  String value.
+     *
+     * @return string         String value.
+     *
+     * @throws UnexpectedTypeException if the given value is not a string
+     */
+    public function reverseTransform($value)
+    {
+        if (null === $value) {
+            return '';
+        }
+
+        if (!is_string($value)) {
+            throw new UnexpectedTypeException($value, 'string');
+        }
+
+        return $value;
+    }
+}

src/Symfony/Component/Form/Extension/Core/Type/TextType.php

@@ -12,9 +12,21 @@
 namespace Symfony\Component\Form\Extension\Core\Type;
 
 use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\FormBuilder;
+use Symfony\Component\Form\Extension\Core\DataTransformer\ValueToStringTransformer;
 
 class TextType extends AbstractType
 {
+    /**
+     * {@inheritdoc}
+     */
+    public function buildForm(FormBuilder $builder, array $options)
+    {
+        $builder
+            ->appendClientTransformer(new ValueToStringTransformer())
+        ;
+    }
+
     /**
      * {@inheritdoc}
      */

tests/Symfony/Tests/Component/Form/Extension/Core/DataTransformer/ValueToStringTransformerTest.php

@@ -0,0 +1,90 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Tests\Component\Form\Extension\Core\DataTransformer;
+
+use Symfony\Component\Form\Extension\Core\DataTransformer\ValueToStringTransformer;
+
+class ValueToStringTransformerTest extends \PHPUnit_Framework_TestCase
+{
+    protected $transformer;
+
+    protected function setUp()
+    {
+        $this->transformer = new ValueToStringTransformer();
+    }
+
+    protected function tearDown()
+    {
+        $this->transformer = null;
+    }
+
+    /**
+     * @dataProvider validDataProvider
+     */
+    public function testTransform($value, $transformed)
+    {
+        $this->assertEquals($transformed, $this->transformer->transform($value));
+    }
+
+    /**
+     * @dataProvider validDataProvider
+     */
+    public function testReverseTransform($value, $transformed)
+    {
+        $this->assertEquals($transformed, $this->transformer->reverseTransform($transformed));
+    }
+
+    public function validDataProvider()
+    {
+        return array(
+            array('test', 'test'),
+            array('', null),
+            array(null, null),
+
+            array(0, '0'),
+            array('0', '0'),
+            array(1, '1'),
+            array('123', '123'),
+            array(1.23, '1.23'),
+        );
+    }
+
+    /**
+     * @dataProvider invalidDataProvider
+     */
+    public function testTransformExpectsStringOrNumber($value)
+    {
+        $this->setExpectedException('Symfony\Component\Form\Exception\UnexpectedTypeException');
+
+        $this->transformer->transform($value);
+    }
+
+    /**
+     * @dataProvider invalidDataProvider
+     */
+    public function testReverseTransformExpectsString($value)
+    {
+        $this->setExpectedException('Symfony\Component\Form\Exception\UnexpectedTypeException');
+
+        $this->transformer->reverseTransform($value);
+    }
+
+    public function invalidDataProvider()
+    {
+        return array(
+            array(true),
+            array(false),
+            array(new \stdClass),
+            array(array()),
+        );
+    }
+}

tests/Symfony/Tests/Component/Form/Extension/Core/Type/UrlTypeTest.php

@@ -46,7 +46,7 @@ class UrlTypeTest extends LocalizedTestCase
 
         $form->bind('');
 
-        $this->assertNull($form->getData());
+        $this->assertSame('', $form->getData());
         $this->assertSame('', $form->getClientData());
     }