* * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Component\String; /** * A string whose value is computed lazily by a callback. * * @author Nicolas Grekas
*/ class LazyString implements \Stringable, \JsonSerializable { private $value; /** * @param callable|array $callback A callable or a [Closure, method] lazy-callable * * @return static */ public static function fromCallable($callback, ...$arguments): self { if (!\is_callable($callback) && !(\is_array($callback) && isset($callback[0]) && $callback[0] instanceof \Closure && 2 >= \count($callback))) { throw new \TypeError(sprintf('Argument 1 passed to "%s()" must be a callable or a [Closure, method] lazy-callable, "%s" given.', __METHOD__, get_debug_type($callback))); } $lazyString = new static(); $lazyString->value = static function () use (&$callback, &$arguments, &$value): string { if (null !== $arguments) { if (!\is_callable($callback)) { $callback[0] = $callback[0](); $callback[1] = $callback[1] ?? '__invoke'; } $value = $callback(...$arguments); $callback = self::getPrettyName($callback); $arguments = null; } return $value ?? ''; }; return $lazyString; } /** * @param string|int|float|bool|\Stringable $value * * @return static */ public static function fromStringable($value): self { if (!self::isStringable($value)) { throw new \TypeError(sprintf('Argument 1 passed to "%s()" must be a scalar or a stringable object, "%s" given.', __METHOD__, get_debug_type($value))); } if (\is_object($value)) { return static::fromCallable([$value, '__toString']); } $lazyString = new static(); $lazyString->value = (string) $value; return $lazyString; } /** * Tells whether the provided value can be cast to string. */ final public static function isStringable($value): bool { return \is_string($value) || $value instanceof self || (\is_object($value) ? method_exists($value, '__toString') : \is_scalar($value)); } /** * Casts scalars and stringable objects to strings. * * @param object|string|int|float|bool $value * * @throws \TypeError When the provided value is not stringable */ final public static function resolve($value): string { return $value; } /** * @return string */ public function __toString() { if (\is_string($this->value)) { return $this->value; } try { return $this->value = ($this->value)(); } catch (\Throwable $e) { if (\TypeError::class === \get_class($e) && __FILE__ === $e->getFile()) { $type = explode(', ', $e->getMessage()); $type = substr(array_pop($type), 0, -\strlen(' returned')); $r = new \ReflectionFunction($this->value); $callback = $r->getStaticVariables()['callback']; $e = new \TypeError(sprintf('Return value of %s() passed to %s::fromCallable() must be of the type string, %s returned.', $callback, static::class, $type)); } if (\PHP_VERSION_ID < 70400) { // leverage the ErrorHandler component with graceful fallback when it's not available return trigger_error($e, \E_USER_ERROR); } throw $e; } } public function __sleep(): array { $this->__toString(); return ['value']; } public function jsonSerialize(): string { return $this->__toString(); } private function __construct() { } private static function getPrettyName(callable $callback): string { if (\is_string($callback)) { return $callback; } if (\is_array($callback)) { $class = \is_object($callback[0]) ? get_debug_type($callback[0]) : $callback[0]; $method = $callback[1]; } elseif ($callback instanceof \Closure) { $r = new \ReflectionFunction($callback); if (false !== strpos($r->name, '{closure}') || !$class = \PHP_VERSION_ID >= 80111 ? $r->getClosureCalledClass() : $r->getClosureScopeClass()) { return $r->name; } $class = $class->name; $method = $r->name; } else { $class = get_debug_type($callback); $method = '__invoke'; } return $class.'::'.$method; } }