Fix rendering select element when value is an object

Author: Erik van Velzen

CHANGELOG.md

@@ -22,6 +22,8 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Fixed
 
+- [#218](https://github.com/zendframework/zend-form/pull/218) ensures object values of select elements can be rendered without error.
+
 - [#216](https://github.com/zendframework/zend-form/pull/216) fixes an issue when performing data binding and a fieldset has no mapped
   input elements, casting `null` values to empty arrays to ensure they can be
   passed to an input filter.

src/View/Helper/FormSelect.php

@@ -285,7 +285,7 @@ protected function validateMultiValue($value, array $attributes)
         }
 
         if (! is_array($value)) {
-            return (array) $value;
+            return [$value];
         }
 
         if (! isset($attributes['multiple']) || ! $attributes['multiple']) {

test/TestAsset/Identifier.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ */
+
+namespace ZendTest\Form\TestAsset;
+
+class Identifier
+{
+    private $id;
+
+    public function __construct($id)
+    {
+        $this->id = $id;
+    }
+
+    public function __toString()
+    {
+        return (string) $this->id;
+    }
+}

test/View/Helper/FormSelectTest.php

@@ -12,6 +12,7 @@
 use Zend\Form\Element;
 use Zend\Form\Element\Select as SelectElement;
 use Zend\Form\View\Helper\FormSelect as FormSelectHelper;
+use ZendTest\Form\TestAsset\Identifier;
 
 class FormSelectTest extends CommonTestCase
 {
@@ -414,4 +415,31 @@ public function testRenderElementWithNoNameRaisesException()
         $this->expectException('Zend\Form\Exception\DomainException');
         $this->helper->render($element);
     }
+
+    public function getElementWithObjectIdentifiers()
+    {
+        $element = new SelectElement('foo');
+        $options = [
+            [
+                'label' => 'This is the first label',
+                'value' => new Identifier(42),
+            ],
+            [
+                'label' => 'This is the second label',
+                'value' => new Identifier(43),
+            ],
+        ];
+        $element->setValueOptions($options);
+        return $element;
+    }
+
+    public function testRenderElementWithObjectIdentifiers()
+    {
+        $element = $this->getElementWithObjectIdentifiers();
+        $element->setValue(new Identifier(42));
+
+        $markup = $this->helper->render($element);
+        $this->assertRegexp('#option .*?value="42" selected="selected"#', $markup);
+        $this->assertNotRegexp('#option .*?value="43" selected="selected"#', $markup);
+    }
 }