<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 3.0.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\I18n;
use Aura\Intl\Package;
use RuntimeException;
/**
* Wraps multiple message loaders calling them one after another until
* one of them returns a non-empty package.
*/
class ChainMessagesLoader
{
/**
* The list of callables to execute one after another for loading messages
*
* @var callable[]
*/
protected $_loaders = [];
/**
* Receives a list of callable functions or objects that will be executed
* one after another until one of them returns a non-empty translations package
*
* @param callable[] $loaders List of callables to execute
*/
public function __construct(array $loaders)
{
$this->_loaders = $loaders;
}
/**
* Executes this object returning the translations package as configured in
* the chain.
*
* @return \Aura\Intl\Package
* @throws \RuntimeException if any of the loaders in the chain is not a valid callable
*/
public function __invoke()
{
foreach ($this->_loaders as $k => $loader) {
if (!is_callable($loader)) {
throw new RuntimeException(sprintf(
'Loader "%s" in the chain is not a valid callable',
$k
));
}
$package = $loader();
if (!$package) {
continue;
}
if (!($package instanceof Package)) {
throw new RuntimeException(sprintf(
'Loader "%s" in the chain did not return a valid Package object',
$k
));
}
return $package;
}
return new Package();
}
}