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feature #28417 [VarExporter] add Instantiator::instantiate() to create+populate objects without calling their constructor nor any other methods (nicolas-grekas)
This PR was merged into the 4.2-dev branch. Discussion ---------- [VarExporter] add Instantiator::instantiate() to create+populate objects without calling their constructor nor any other methods | Q | A | ------------- | --- | Branch? | master | Bug fix? | no | New feature? | yes | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | - | License | MIT | Doc PR | - A blend of features also provided by https://github.com/doctrine/instantiator and https://github.com/Ocramius/GeneratedHydrator in one simple method. Because it's just a few more lines on top of the existing code infrastructure in the component :) For example, from the docblock: ```php // creates an empty instance of Foo Instantiator::instantiate(Foo::class); // creates a Foo instance and sets one of its public, protected or private properties Instantiator::instantiate(Foo::class, ['propertyName' => $propertyValue]); // creates a Foo instance and sets a private property defined on its parent Bar class Instantiator::instantiate(Foo::class, [], [ Bar::class => ['privateBarProperty' => $propertyValue], ]); ``` Instances of ArrayObject, ArrayIterator and SplObjectHash can be created by using the special `"\0"` property name to define their internal value: ```php // creates an SplObjectHash where $info1 is attached to $obj1, etc. Instantiator::instantiate(SplObjectStorage::class, ["\0" => [$obj1, $info1, $obj2, $info2...]]); // creates an ArrayObject populated with $inputArray Instantiator::instantiate(ArrayObject::class, ["\0" => [$inputArray, $optionalFlag]]); ``` Misses some tests for now, but reuses the existing code infrastructure used to "unserialize" objects. Commits ------- d9bade0 [VarExporter] add Instantiator::instantiate() to create+populate objects without calling their constructor nor any other methods
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‎src/Symfony/Component/VarExporter/Instantiator.php

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<?php
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/*
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* This file is part of the Symfony package.
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*
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* (c) Fabien Potencier <[email protected]>
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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namespace Symfony\Component\VarExporter;
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use Symfony\Component\VarExporter\Exception\ExceptionInterface;
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use Symfony\Component\VarExporter\Exception\NotInstantiableTypeException;
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use Symfony\Component\VarExporter\Internal\Hydrator;
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use Symfony\Component\VarExporter\Internal\Registry;
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/**
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* A utility class to create objects without calling their constructor.
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*
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* @author Nicolas Grekas <[email protected]>
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*/
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final class Instantiator
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{
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/**
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* Creates an object and sets its properties without calling its constructor nor any other methods.
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*
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* For example:
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*
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* // creates an empty instance of Foo
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* Instantiator::instantiate(Foo::class);
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*
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* // creates a Foo instance and sets one of its properties
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* Instantiator::instantiate(Foo::class, ['propertyName' => $propertyValue]);
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*
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* // creates a Foo instance and sets a private property defined on its parent Bar class
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* Instantiator::instantiate(Foo::class, [], [
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* Bar::class => ['privateBarProperty' => $propertyValue],
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* ]);
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*
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* Instances of ArrayObject, ArrayIterator and SplObjectHash can be created
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* by using the special "\0" property name to define their internal value:
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*
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* // creates an SplObjectHash where $info1 is attached to $obj1, etc.
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* Instantiator::instantiate(SplObjectStorage::class, ["\0" => [$obj1, $info1, $obj2, $info2...]]);
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*
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* // creates an ArrayObject populated with $inputArray
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* Instantiator::instantiate(ArrayObject::class, ["\0" => [$inputArray]]);
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*
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* @param string $class The class of the instance to create
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* @param array $properties The properties to set on the instance
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* @param array $privateProperties The private properties to set on the instance,
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* keyed by their declaring class
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*
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* @return object The created instance
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*
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* @throws ExceptionInterface When the instance cannot be created
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*/
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public static function instantiate(string $class, array $properties = array(), array $privateProperties = array())
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{
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$reflector = Registry::$reflectors[$class] ?? Registry::getClassReflector($class);
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if (Registry::$cloneable[$class]) {
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$wrappedInstance = array(clone Registry::$prototypes[$class]);
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} elseif (Registry::$instantiableWithoutConstructor[$class]) {
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$wrappedInstance = array($reflector->newInstanceWithoutConstructor());
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} elseif (null === Registry::$prototypes[$class]) {
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throw new NotInstantiableTypeException($class);
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} elseif ($reflector->implementsInterface('Serializable')) {
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$wrappedInstance = array(unserialize('C:'.\strlen($class).':"'.$class.'":0:{}'));
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} else {
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$wrappedInstance = array(unserialize('O:'.\strlen($class).':"'.$class.'":0:{}'));
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}
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if ($properties) {
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$privateProperties[$class] = isset($privateProperties[$class]) ? $properties + $privateProperties[$class] : $properties;
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}
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foreach ($privateProperties as $class => $properties) {
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if (!$properties) {
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continue;
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}
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foreach ($properties as $name => $value) {
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// because they're also used for "unserialization", hydrators
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// deal with array of instances, so we need to wrap values
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$properties[$name] = array($value);
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}
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(Hydrator::$hydrators[$class] ?? Hydrator::getHydrator($class))($properties, $wrappedInstance);
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}
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return $wrappedInstance[0];
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}
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}

‎src/Symfony/Component/VarExporter/README.md

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@@ -5,6 +5,9 @@ The VarExporter component allows exporting any serializable PHP data structure t
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plain PHP code. While doing so, it preserves all the semantics associated with
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the serialization mechanism of PHP (`__wakeup`, `__sleep`, `Serializable`).
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It also provides an instantiator that allows creating and populating objects
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without calling their constructor nor any other methods.
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The reason to use this component *vs* `serialize()` or
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[igbinary](https://github.com/igbinary/igbinary) is performance: thanks to
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OPcache, the resulting code is significantly faster and more memory efficient

‎src/Symfony/Component/VarExporter/Tests/InstantiatorTest.php

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<?php
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/*
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* This file is part of the Symfony package.
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*
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* (c) Fabien Potencier <[email protected]>
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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namespace Symfony\Component\VarExporter\Tests;
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use PHPUnit\Framework\TestCase;
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use Symfony\Component\VarExporter\Instantiator;
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class InstantiatorTest extends TestCase
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{
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/**
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* @expectedException \Symfony\Component\VarExporter\Exception\ClassNotFoundException
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* @expectedExceptionMessage Class "SomeNotExistingClass" not found.
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*/
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public function testNotFoundClass()
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{
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Instantiator::instantiate('SomeNotExistingClass');
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}
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/**
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* @dataProvider provideFailingInstantiation
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* @expectedException \Symfony\Component\VarExporter\Exception\NotInstantiableTypeException
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* @expectedExceptionMessageRegexp Type ".*" is not instantiable.
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*/
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public function testFailingInstantiation(string $class)
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{
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Instantiator::instantiate($class);
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}
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public function provideFailingInstantiation()
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{
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yield array('ReflectionClass');
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yield array('SplHeap');
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yield array('Throwable');
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yield array('Closure');
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yield array('SplFileInfo');
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}
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public function testInstantiate()
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{
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$this->assertEquals((object) array('p' => 123), Instantiator::instantiate('stdClass', array('p' => 123)));
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$this->assertEquals((object) array('p' => 123), Instantiator::instantiate('STDcLASS', array('p' => 123)));
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$this->assertEquals(new \ArrayObject(array(123)), Instantiator::instantiate(\ArrayObject::class, array("\0" => array(array(123)))));
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$expected = array(
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"\0".__NAMESPACE__."\Bar\0priv" => 123,
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"\0".__NAMESPACE__."\Foo\0priv" => 234,
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);
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$this->assertSame($expected, (array) Instantiator::instantiate(Bar::class, array('priv' => 123), array(Foo::class => array('priv' => 234))));
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$e = Instantiator::instantiate('Exception', array('foo' => 123, 'trace' => array(234)));
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$this->assertSame(123, $e->foo);
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$this->assertSame(array(234), $e->getTrace());
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}
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}
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class Foo
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{
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private $priv;
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}
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class Bar extends Foo
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{
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private $priv;
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}

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