<?php
namespace Invoker;
use Invoker\Exception\NotCallableException;
use Psr\Container\ContainerInterface;
use Psr\Container\NotFoundExceptionInterface;
/**
* Resolves a callable from a container.
*
* @author Matthieu Napoli <[email protected]>
*/
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 $callable
*
* @return callable Real PHP callable.
*
* @throws NotCallableException
*/
public function resolve($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 $callable
* @return callable
* @throws NotCallableException
*/
private function resolveFromContainer($callable)
{
// Shortcut for a very common use case
if ($callable instanceof \Closure) {
return $callable;
}
$isStaticCallToNonStaticMethod = false;
// If it's already a callable there is nothing to do
if (is_callable($callable)) {
$isStaticCallToNonStaticMethod = $this->isStaticCallToNonStaticMethod($callable);
if (! $isStaticCallToNonStaticMethod) {
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 $e;
}
if ($isStaticCallToNonStaticMethod) {
throw new NotCallableException(sprintf(
'Cannot call %s::%s() because %s() is not a static method and "%s" is not a container entry',
$callable[0],
$callable[1],
$callable[1],
$callable[0]
));
}
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 $callable
* @return bool
*/
private function isStaticCallToNonStaticMethod($callable)
{
if (is_array($callable) && is_string($callable[0])) {
list($class, $method) = $callable;
$reflection = new \ReflectionMethod($class, $method);
return ! $reflection->isStatic();
}
return false;
}
}