StreamDecoratorTrait.php

<?php

declare (strict_types=1);
namespace GuzzleHttp\Psr7;

use Psr\Http\Message\StreamInterface;

/**
 * Stream decorator trait
 *
 * @property StreamInterface $stream
 */
trait StreamDecoratorTrait {
    
    /**
     * @param StreamInterface $stream Stream to decorate
     */
    public function __construct(StreamInterface $stream) {
        $this->stream = $stream;
    }
    
    /**
     * Magic method used to create a new stream if streams are not added in
     * the constructor of a decorator (e.g., LazyOpenStream).
     *
     * @return StreamInterface
     */
    public function __get(string $name) {
        if ($name === 'stream') {
            $this->stream = $this->createStream();
            return $this->stream;
        }
        throw new \UnexpectedValueException("{$name} not found on class");
    }
    public function __toString() : string {
        try {
            if ($this->isSeekable()) {
                $this->seek(0);
            }
            return $this->getContents();
        } catch (\Throwable $e) {
            if (\PHP_VERSION_ID >= 70400) {
                throw $e;
            }
            trigger_error(sprintf('%s::__toString exception: %s', self::class, (string) $e), E_USER_ERROR);
            return '';
        }
    }
    public function getContents() : string {
        return Utils::copyToString($this);
    }
    
    /**
     * Allow decorators to implement custom methods
     *
     * @return mixed
     */
    public function __call(string $method, array $args) {
        
        /** @var callable $callable */
        $callable = [
            $this->stream,
            $method,
        ];
        $result = $callable(...$args);
        // Always return the wrapped object if the result is a return $this
        return $result === $this->stream ? $this : $result;
    }
    public function close() : void {
        $this->stream
            ->close();
    }
    
    /**
     * @return mixed
     */
    public function getMetadata($key = null) {
        return $this->stream
            ->getMetadata($key);
    }
    public function detach() {
        return $this->stream
            ->detach();
    }
    public function getSize() : ?int {
        return $this->stream
            ->getSize();
    }
    public function eof() : bool {
        return $this->stream
            ->eof();
    }
    public function tell() : int {
        return $this->stream
            ->tell();
    }
    public function isReadable() : bool {
        return $this->stream
            ->isReadable();
    }
    public function isWritable() : bool {
        return $this->stream
            ->isWritable();
    }
    public function isSeekable() : bool {
        return $this->stream
            ->isSeekable();
    }
    public function rewind() : void {
        $this->seek(0);
    }
    public function seek($offset, $whence = SEEK_SET) : void {
        $this->stream
            ->seek($offset, $whence);
    }
    public function read($length) : string {
        return $this->stream
            ->read($length);
    }
    public function write($string) : int {
        return $this->stream
            ->write($string);
    }
    
    /**
     * Implement in subclasses to dynamically create streams when requested.
     *
     * @throws \BadMethodCallException
     */
    protected function createStream() : StreamInterface {
        throw new \BadMethodCallException('Not implemented');
    }

}