[Form] added `CallbackChoiceLoader`

src/Symfony/Component/Form/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+3.2.0
+-----
+
+ * added `CallbackChoiceLoader`
+
 3.1.0
 -----
 

src/Symfony/Component/Form/ChoiceList/Loader/CallbackChoiceLoader.php

@@ -0,0 +1,77 @@
+<?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\ChoiceList\Loader;
+
+use Symfony\Component\Form\ChoiceList\ArrayChoiceList;
+
+/**
+ * Loads an {@link ArrayChoiceList} instance from a callable returning an array of choices.
+ *
+ * @author Jules Pietri <jules@heahprod.com>
+ */
+class CallbackChoiceLoader implements ChoiceLoaderInterface
+{
+    private $callback;
+
+    /**
+     * The loaded choice list.
+     *
+     * @var ArrayChoiceList
+     */
+    private $choiceList;
+
+    /**
+     * @param callable $callback The callable returning an array of choices
+     */
+    public function __construct(callable $callback)
+    {
+        $this->callback = $callback;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function loadChoiceList($value = null)
+    {
+        if (null !== $this->choiceList) {
+            return $this->choiceList;
+        }
+
+        return $this->choiceList = new ArrayChoiceList(call_user_func($this->callback), $value);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function loadChoicesForValues(array $values, $value = null)
+    {
+        // Optimize
+        if (empty($values)) {
+            return array();
+        }
+
+        return $this->loadChoiceList($value)->getChoicesForValues($values);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function loadValuesForChoices(array $choices, $value = null)
+    {
+        // Optimize
+        if (empty($choices)) {
+            return array();
+        }
+
+        return $this->loadChoiceList($value)->getValuesForChoices($choices);
+    }
+}

src/Symfony/Component/Form/Tests/ChoiceList/Loader/CallbackChoiceLoaderTest.php

@@ -0,0 +1,101 @@
+<?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\Tests\ChoiceList\Loader;
+
+use Symfony\Component\Form\ChoiceList\LazyChoiceList;
+use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+
+/**
+ * @author Jules Pietri <jules@heahprod.com>
+ */
+class CallbackChoiceLoaderTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var \Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader
+     */
+    static private $loader;
+
+    /**
+     * @var callable
+     */
+    static private $value;
+
+    /**
+     * @var array
+     */
+    static private $choices;
+
+    /**
+     * @var string[]
+     */
+    static private $choiceValues;
+
+    /**
+     * @var \Symfony\Component\Form\ChoiceList\LazyChoiceList
+     */
+    static private $lazyChoiceList;
+
+    static public function setUpBeforeClass()
+    {
+        self::$loader = new CallbackChoiceLoader(function() {
+            return self::$choices;
+        });
+        self::$value = function ($choice) {
+            return isset($choice->value) ? $choice->value : null;
+        };
+        self::$choices = array(
+            (object) array('value' => 'choice_one'),
+            (object) array('value' => 'choice_two'),
+        );
+        self::$choiceValues = array('choice_one', 'choice_two');
+        self::$lazyChoiceList = new LazyChoiceList(self::$loader, self::$value);
+    }
+
+    public function testLoadChoiceList()
+    {
+        $this->assertInstanceOf('\Symfony\Component\Form\ChoiceList\ChoiceListInterface', self::$loader->loadChoiceList(self::$value));
+    }
+
+    public function testLoadChoiceListOnlyOnce()
+    {
+        $loadedChoiceList = self::$loader->loadChoiceList(self::$value);
+
+        $this->assertSame($loadedChoiceList, self::$loader->loadChoiceList(self::$value));
+    }
+
+    public function testLoadChoicesForValuesLoadsChoiceListOnFirstCall()
+    {
+        $this->assertSame(
+            self::$loader->loadChoicesForValues(self::$choiceValues, self::$value),
+            self::$lazyChoiceList->getChoicesForValues(self::$choiceValues),
+            'Choice list should not be reloaded.'
+        );
+    }
+
+    public function testLoadValuesForChoicesLoadsChoiceListOnFirstCall()
+    {
+        $this->assertSame(
+            self::$loader->loadValuesForChoices(self::$choices, self::$value),
+            self::$lazyChoiceList->getValuesForChoices(self::$choices),
+            'Choice list should not be reloaded.'
+        );
+    }
+
+    static public function tearDownAfterClass()
+    {
+        self::$loader = null;
+        self::$value = null;
+        self::$choices = array();
+        self::$choiceValues = array();
+        self::$lazyChoiceList = null;
+    }
+}