* * @implements \IteratorAggregate */ class InputStream implements \IteratorAggregate { /** @var callable|null */ private $onEmpty = null; private $input = []; private $open = true; /** * Sets a callback that is called when the write buffer becomes empty. */ public function onEmpty(callable $onEmpty = null) { $this->onEmpty = $onEmpty; } /** * Appends an input to the write buffer. * * @param resource|string|int|float|bool|\Traversable|null $input The input to append as scalar, * stream resource or \Traversable */ public function write($input) { if (null === $input) { return; } if ($this->isClosed()) { throw new RuntimeException(sprintf('"%s" is closed.', static::class)); } $this->input[] = ProcessUtils::validateInput(__METHOD__, $input); } /** * Closes the write buffer. */ public function close() { $this->open = false; } /** * Tells whether the write buffer is closed or not. */ public function isClosed() { return !$this->open; } /** * @return \Traversable */ #[\ReturnTypeWillChange] public function getIterator() { $this->open = true; while ($this->open || $this->input) { if (!$this->input) { yield ''; continue; } $current = array_shift($this->input); if ($current instanceof \Iterator) { yield from $current; } else { yield $current; } if (!$this->input && $this->open && null !== $onEmpty = $this->onEmpty) { $this->write($onEmpty($this)); } } } }