<?php declare(strict_types=1);
namespace Invoker;
use Closure;
use Invoker\Exception\NotCallableException;
use Psr\Container\ContainerInterface;
use Psr\Container\NotFoundExceptionInterface;
use ReflectionException;
use ReflectionMethod;
/**
* Resolves a callable from a container.
*/
class CallableResolver
{
/** @var ContainerInterface */
private $container;
public function __construct(ContainerInterface $container)
{
$this->container = $container;
}
/**
* Resolve the given callable into a real PHP callable.
*
* @param callable|string|array $callable
* @return callable Real PHP callable.
* @throws NotCallableException|ReflectionException
*/
public function resolve($callable): callable
{
if (is_string($callable) && strpos($callable, '::') !== false) {
$callable = explode('::', $callable, 2);
}
$callable = $this->resolveFromContainer($callable);
if (! is_callable($callable)) {
throw NotCallableException::fromInvalidCallable($callable, true);
}
return $callable;
}
/**
* @param callable|string|array $callable
* @return callable|mixed
* @throws NotCallableException|ReflectionException
*/
private function resolveFromContainer($callable)
{
// Shortcut for a very common use case
if ($callable instanceof Closure) {
return $callable;
}
// If it's already a callable there is nothing to do
if (is_callable($callable)) {
// TODO with PHP 8 that should not be necessary to check this anymore
if (! $this->isStaticCallToNonStaticMethod($callable)) {
return $callable;
}
}
// The callable is a container entry name
if (is_string($callable)) {
try {
return $this->container->get($callable);
} catch (NotFoundExceptionInterface $e) {
if ($this->container->has($callable)) {
throw $e;
}
throw NotCallableException::fromInvalidCallable($callable, true);
}
}
// The callable is an array whose first item is a container entry name
// e.g. ['some-container-entry', 'methodToCall']
if (is_array($callable) && is_string($callable[0])) {
try {
// Replace the container entry name by the actual object
$callable[0] = $this->container->get($callable[0]);
return $callable;
} catch (NotFoundExceptionInterface $e) {
if ($this->container->has($callable[0])) {
throw $e;
}
throw new NotCallableException(sprintf(
'Cannot call %s() on %s because it is not a class nor a valid container entry',
$callable[1],
$callable[0]
));
}
}
// Unrecognized stuff, we let it fail later
return $callable;
}
/**
* Check if the callable represents a static call to a non-static method.
*
* @param mixed $callable
* @throws ReflectionException
*/
private function isStaticCallToNonStaticMethod($callable): bool
{
if (is_array($callable) && is_string($callable[0])) {
[$class, $method] = $callable;
if (! method_exists($class, $method)) {
return false;
}
$reflection = new ReflectionMethod($class, $method);
return ! $reflection->isStatic();
}
return false;
}
}