I would like to receive criticism of this code.

Question

This is the use of the "Factory" pattern, I ask for help to understand if I use it correctly.

<?php Class HelloFactory { static $config = "My"; public static function createHello() { $fullNameClass = self::$config . "Hello"; return new $fullNameClass; } } Class CustomHello { public function view() { return "hello world!"; } } Class MyHello { public function view() { return "hello everybody"; } } $test = HelloFactory::createHello(); echo $test->view();

Dmitriy Simushev 15.5k 3 37 75 · Accepted Answer · 2016-01-27T09:39:03

Not quite right. The factory must create any object. For example extending one interface or abstract class.

 <?php class HelloFactory { static $parentClass = "Hello"; /** * @param string $className * @return Hello * @throws \Exception */ public static function create($className) { if(!class_exists($className)) { throw new \Exception("Класс $className не найден"); } if(!in_array(self::$parentClass, class_parents($className))) { throw new \Exception("Класс $className не наследует абстрактный класс " . self::$parentClass); } $object = new $className(); // делегируем конфигурацию объекта самому объекту, иначе в фабрике много лишней логики и кода $object->init(); return $object; } } abstract class Hello { public $message; // инициализация объекта abstract function init(); public function view() { return $this->message; } } class HelloWorld extends Hello { public function init() { $this->message = 'hello world!'; } } class HelloEveryBody extends Hello { public function init() { $this->message = 'hello everybody!'; } } $test = HelloFactory::create('HelloWorld'); echo $test->view() . PHP_EOL; $test2 = HelloFactory::create('HelloEveryBody'); echo $test2->view() . PHP_EOL; // получаем исключение $test3 = HelloFactory::create('HelloAnyBody'); echo $test3->view() . PHP_EOL;

2. This is a demo code, in a real project, of course, you can use DI and create a factory via services
Problems start when you need to pass an object to the product designer.
Then either static properties or bloated HelloFactory::create signature with DIP violation

Zhukov Roman Zhukov Roman 8,890 ten 26 · Answer 2 · 2016-01-27T08:13:33

In this implementation, your factory can only create objects of the MyHello class, and should create objects of different classes. Look at a small article , everything is clearly written there. Write the interface that the generated classes will implement and complete the description of the createHello() method using PHPDoc and everything will be fine.

The object creation code will look something like this: public static function createHello($config) { $fullNameClass = $config . "Hello"; return new $fullNameClass; }
public static function createHello($config) { $fullNameClass = $config . "Hello"; return new $fullNameClass; }
public static function createHello($config) { $fullNameClass = $config . "Hello"; return new $fullNameClass; } Call accordingly: $test = HelloFactory::createHello('Custom'); echo $test->view();
$test = HelloFactory::createHello('Custom'); echo $test->view();

I would like to receive criticism of this code.

2 answers 2

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