StringRepository.php

<?php

interface StringSignatureStorage
{
	function save(string $resourceId, array $keys);
}

interface StringStorageInterface
{
	function fetch(string $resourceId);
}

interface StringCompiler
{
	function compile(string $content, array $values);
}

class StringSignatureFileStorage implements StringSignatureStorage
{
    public function save(string $resourceId, array $keys) {
        file_put_contents('./resources/' . $resourceId,
			'<?php return ' . var_export($keys, true) . ';');
    }
}

class SimpleStringCompiler implements StringCompiler
{
	public function compile(string $content, array $values)
	{
		return preg_replace_callback('/%([\w]+)%/', function($matches) use ($values) {
            return !empty($values[$matches[1]]) ? $values[$matches[1]] : null;
        }, $content);
	}
}

class DummyStringRepository implements StringStorageInterface
{
	public function fetch(string $resourceId)
	{
		return $resourceId;
	}
}

class StringRepository
{
	private $signatureStorage;
	private $stringCompiler;
	private $stringStorage;

    public function __construct(StringSignatureStorage $signatureStorage,
		StringStorageInterface $stringStorage, StringCompiler $stringCompiler) {

        $this->signatureStorage = $signatureStorage;
		$this->stringStorage = $stringStorage;
		$this->stringCompiler = $stringCompiler;
    }

    public function render(string $resourceId, array $values = []): string {
        $this->signatureStorage->save($resourceId, array_keys($values));

        return $this->stringCompiler->compile($this->stringStorage->fetch($resourceId),
			$values);
    }
}

$stringRepository = new StringRepository(new StringSignatureFileStorage,
	new DummyStringRepository, new SimpleStringCompiler);

var_dump($stringRepository->render('witam %name%!', [
    'name' => 'aleks'
]));

var_dump($stringRepository->render('hello.world.resourceId', [
    'name' => 'aleks'
]));