use GuzzleHttp\Promise\PromiseInterface;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
* Creates a composed Guzzle handler function by stacking middlewares on top of
* an HTTP handler function.
/** @var callable|null */
/** @var callable|null */
* Creates a default handler stack that can be used by clients.
* The returned handler will wrap the provided handler or use the most
* appropriate default handler for your system. The returned HandlerStack has
* support for cookies, redirects, HTTP error exceptions, and preparing a body
* The returned handler stack can be passed to a client in the "handler"
* @param callable $handler HTTP handler function to use with the stack. If no
* handler is provided, the best handler for your
* system will be utilized.
public static function create(callable $handler = null)
$stack = new self($handler ?: choose_handler());
$stack->push(Middleware::httpErrors(), 'http_errors');
$stack->push(Middleware::redirect(), 'allow_redirects');
$stack->push(Middleware::cookies(), 'cookies');
$stack->push(Middleware::prepareBody(), 'prepare_body');
* @param callable $handler Underlying HTTP handler.
public function __construct(callable $handler = null)
$this->handler = $handler;
* Invokes the handler stack as a composed handler
* @param RequestInterface $request
* @return ResponseInterface|PromiseInterface
public function __invoke(RequestInterface $request, array $options)
$handler = $this->resolve();
return $handler($request, $options);
* Dumps a string representation of the stack.
public function __toString()
$stack[] = "0) Handler: " . $this->debugCallable($this->handler);
foreach (array_reverse($this->stack) as $tuple) {
$str = "{$depth}) Name: '{$tuple[1]}', ";
$str .= "Function: " . $this->debugCallable($tuple[0]);
$result = "> {$str}\n{$result}";
foreach (array_keys($stack) as $k) {
$result .= "< {$stack[$k]}\n";
* Set the HTTP handler that actually returns a promise.
* @param callable $handler Accepts a request and array of options and
public function setHandler(callable $handler)
$this->handler = $handler;
* Returns true if the builder has a handler.
public function hasHandler()
return (bool) $this->handler;
* Unshift a middleware to the bottom of the stack.
* @param callable $middleware Middleware function
* @param string $name Name to register for this middleware.
public function unshift(callable $middleware, $name = null)
array_unshift($this->stack, [$middleware, $name]);
* Push a middleware to the top of the stack.
* @param callable $middleware Middleware function
* @param string $name Name to register for this middleware.
public function push(callable $middleware, $name = '')
$this->stack[] = [$middleware, $name];
* Add a middleware before another middleware by name.
* @param string $findName Middleware to find
* @param callable $middleware Middleware function
* @param string $withName Name to register for this middleware.
public function before($findName, callable $middleware, $withName = '')
$this->splice($findName, $withName, $middleware, true);
* Add a middleware after another middleware by name.
* @param string $findName Middleware to find
* @param callable $middleware Middleware function
* @param string $withName Name to register for this middleware.
public function after($findName, callable $middleware, $withName = '')
$this->splice($findName, $withName, $middleware, false);
* Remove a middleware by instance or name from the stack.
* @param callable|string $remove Middleware to remove by instance or name.
public function remove($remove)
$idx = is_callable($remove) ? 0 : 1;
$this->stack = array_values(array_filter(
function ($tuple) use ($idx, $remove) {
return $tuple[$idx] !== $remove;
* Compose the middleware and handler into a single callable function.
public function resolve()
if (!($prev = $this->handler)) {
throw new \LogicException('No handler has been specified');
foreach (array_reverse($this->stack) as $fn) {
private function findByName($name)
foreach ($this->stack as $k => $v) {
throw new \InvalidArgumentException("Middleware not found: $name");
* Splices a function into the middleware list at a specific position.
* @param string $findName
* @param string $withName
* @param callable $middleware
private function splice($findName, $withName, callable $middleware, $before)
$idx = $this->findByName($findName);
$tuple = [$middleware, $withName];
array_unshift($this->stack, $tuple);
$replacement = [$tuple, $this->stack[$idx]];
array_splice($this->stack, $idx, 1, $replacement);
} elseif ($idx === count($this->stack) - 1) {
$replacement = [$this->stack[$idx], $tuple];
array_splice($this->stack, $idx, 1, $replacement);
* Provides a debug string for a given callable.
* @param array|callable $fn Function to write as a string.
private function debugCallable($fn)
return "callable({$fn})";
? "callable({$fn[0]}::{$fn[1]})"
: "callable(['" . get_class($fn[0]) . "', '{$fn[1]}'])";
return 'callable(' . spl_object_hash($fn) . ')';
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
