Adds EnumSerializableTrait - fixes #52

Author: marc-mabe

composer.json

@@ -24,6 +24,9 @@
         "php":            ">=5.3",
         "ext-reflection": "*"
     },
+    "suggest": {
+        "php": "PHP>=5.4 will be required for using trait EnumSerializableTrait"
+    },
     "require-dev": {
         "phpunit/phpunit": "~4.0"
     },

src/EnumSerializableTrait.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace MabeEnum;
+
+use RuntimeException;
+use LogicException;
+
+/**
+ * Trait to make enumerations serializable
+ *
+ * This trait is a workaround to make enumerations serializable.
+ *
+ * Please note that this feature breaks singleton behaviour of your enumerations
+ * if an enumeration will be unserialized after it was instantiated already.
+ *
+ * @link https://github.com/marc-mabe/php-enum/issues/52 for further information about this feature
+ * @link http://github.com/marc-mabe/php-enum for the canonical source repository
+ * @copyright Copyright (c) 2015 Marc Bennewitz
+ * @license http://github.com/marc-mabe/php-enum/blob/master/LICENSE.txt New BSD License
+ */
+trait EnumSerializableTrait
+{
+    /**
+     * The method will be defined by MabeEnum\Enum
+     * @return null|bool|int|float|string
+     */
+    abstract public function getValue();
+
+    /**
+     * Serialized the value of the enumeration
+     * This will be called automatically on `serialize()` if the enumeration implements the `Serializable` interface
+     * @return string
+     */
+    public function serialize()
+    {
+        return serialize($this->getValue());
+    }
+
+    /**
+     * Unserializes a given serialized value and push it into the current instance
+     * This will be called automatically on `unserialize()` if the enumeration implements the `Serializable` interface
+     * @param string
+     * @throws RuntimeException On an unknown or invalid value
+     * @throws LogicException   On changing numeration value by calling this directly
+     */
+    public function unserialize($serialized)
+    {
+        $value     = unserialize($serialized);
+        $constants = self::getConstants();
+        $name      = array_search($value, $constants, true);
+        if ($name === false) {
+            if (is_scalar($value)) {
+                $message = 'Unknown value ' . var_export($value, true);
+            } else {
+                $message = 'Invalid value of type ' . (is_object($value) ? get_class($value) : gettype($value));
+            }
+            throw new RuntimeException($message);
+        }
+
+        $class      = get_class($this);
+        $enumerator = $this;
+        $closure    = function () use ($class, $name, $value, $enumerator) {
+            if ($this->value !== null && $value !== null) {
+                throw new LogicException('Do not call this directly - please use unserialize($enum) instead');
+            }
+
+            $this->value = $value;
+
+            if (!isset(self::$instances[$class][$name])) {
+                self::$instances[$class][$name] = $enumerator;
+            }
+        };
+        $closure = $closure->bindTo($this, 'MabeEnum\Enum');
+        $closure();
+    }
+}

tests/MabeEnumTest/EnumSerializableTraitTest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace MabeEnumTest;
+
+use MabeEnumTest\TestAsset\SerializableEnum;
+use PHPUnit_Framework_TestCase as TestCase;
+
+/**
+ * Unit tests for the trait MabeEnum\EnumSerializableTrait
+ *
+ * @link http://github.com/marc-mabe/php-enum for the canonical source repository
+ * @copyright Copyright (c) 2015 Marc Bennewitz
+ * @license http://github.com/marc-mabe/php-enum/blob/master/LICENSE.txt New BSD License
+ */
+class EnumSerializableTraitTest extends TestCase
+{
+    public function setUp()
+    {
+        if (version_compare(PHP_VERSION, '5.4', '<')) {
+            $this->markTestSkipped('Traits require PHP-5.4');
+        }
+
+        SerializableEnum::clear();
+    }
+
+    public function testSerializeSerializableEnum()
+    {
+        $serialized = serialize(SerializableEnum::get(SerializableEnum::NIL));
+        $this->assertInternalType('string', $serialized);
+
+        $unserialized = unserialize($serialized);
+        $this->assertInstanceOf('MabeEnumTest\TestAsset\SerializableEnum', $unserialized);
+    }
+
+    public function testUnserializeFirstWillHoldTheSameInstance()
+    {
+        $serialized = serialize(SerializableEnum::get(SerializableEnum::STR));
+        $this->assertInternalType('string', $serialized);
+
+        // clear all instantiated instances so we can virtual test unserializing first
+        SerializableEnum::clear();
+
+        // First unserialize
+        $unserialized = unserialize($serialized);
+        $this->assertInstanceOf('MabeEnumTest\TestAsset\SerializableEnum', $unserialized);
+
+        // second instantiate
+        $enum = SerializableEnum::get($unserialized->getValue());
+
+        // check if it's the same instance
+        $this->assertSame($enum, $unserialized);
+    }
+
+    public function testUnserializeThrowsRuntimeExceptionOnUnknownValue()
+    {
+        $this->setExpectedException('RuntimeException');
+        unserialize('C:39:"MabeEnumTest\TestAsset\SerializableEnum":11:{s:4:"test";}');
+    }
+
+    public function testUnserializeThrowsRuntimeExceptionOnInvalidValue()
+    {
+        $this->setExpectedException('RuntimeException');
+        unserialize('C:39:"MabeEnumTest\TestAsset\SerializableEnum":19:{O:8:"stdClass":0:{}}');
+    }
+
+    public function testUnserializeThrowsLogicExceptionOnChangingValue()
+    {
+        $this->setExpectedException('LogicException');
+        $enum = SerializableEnum::get(SerializableEnum::INT);
+        $enum->unserialize(serialize(SerializableEnum::STR));
+    }
+}

tests/MabeEnumTest/TestAsset/SerializableEnum.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace MabeEnumTest\TestAsset;
+
+use MabeEnum\Enum;
+use MabeEnum\EnumSerializableTrait;
+use Serializable;
+
+/**
+ * Unit tests for the class MabeEnum\EnumSerializableTrait
+ *
+ * @link http://github.com/marc-mabe/php-enum for the canonical source repository
+ * @copyright Copyright (c) 2015 Marc Bennewitz
+ * @license http://github.com/marc-mabe/php-enum/blob/master/LICENSE.txt New BSD License
+ */
+class SerializableEnum extends Enum implements Serializable
+{
+    use EnumSerializableTrait;
+
+    const INT = 0;
+    const NIL = null;
+    const STR = '';
+}