This article contains explanations of common PHP Stan issues or copy & paste ready code snippets.
Generic type for “Collection”
Let’s say we want to create a custom Collection of type T that will be iterable and will contain method getItems. We want to PHP Stan do ensure a provided item is of type T e.g. T = SomeEntity:
Collection.php
<?php
use IteratorAggregate;
use Traversable;
/**
* @template T
*/
abstract class Collection implements IteratorAggregate
{
/**
* @var array<int, T> $items
*/
private array $items;
/**
* @return array<int, T>
*/
abstract public function getItems(): array;
/**
* @return Traversable<int, T>
*/
abstract public function getIterator(): Traversable;
}Then we can create new Collection like the following:
PHP
$collection = new Collection([new SomeEntity(1), new SomeEntity(2)]);
foreach ($collection as $entity) {
// $entity - of type SomeEntity
}
foreach ($collection->getItems() as $entity) {
// $entity - of type SomeEntity
}Returning T by class-string
This is common scenario when we want to pass class-string param and return this type T object.
PHP
abstract class IntegrationTestCase extends KernelTestCase
{
/**
* @template T
* @param class-string<T> $name
* @return T
*/
public static function getService(string $name)
{
return self::getContainer()->get($name);
}
}Limiting string to N values (like ENUM)
Assuming we have a function argument of type string but we want only to accept value1 or value2
PHP
/**
* @param 'time'|'notTime'|null $unitTypeKind
*/
private function validateCommon(?string $unitTypeKind): void
{
//
}