1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 <?php
namespace Alpha\Util\Service;
use Alpha\Exception\IllegalArguementException;
use Alpha\Util\Logging\Logger;
/**
* A factory for creating service instances that match the provider name and interface provided
*
* @since 3.0
*
* @author John Collins <dev@alphaframework.org>
* @license http://www.opensource.org/licenses/bsd-license.php The BSD License
* @copyright Copyright (c) 2018, John Collins (founder of Alpha Framework).
* All rights reserved.
*
* <pre>
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the
* following conditions are met:
*
* * Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
* * Neither the name of the Alpha Framework nor the names
* of its contributors may be used to endorse or promote
* products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* </pre>
*/
class ServiceFactory
{
/**
* Trace logger.
*
* @var \Alpha\Util\Logging\Logger
*
* @since 3.0
*/
private static $logger = null;
/**
* A static array of service singletons in case any service needs to be accessed as a single instance.
*
* @var array
*
* @since 3.0
*/
private static $singletons = array();
/**
* A static method that attempts to return a service provider instance
* based on the name of the provider class supplied. If the instance does not
* implement the desired interface, an exception is thrown.
*
* @param string $serviceName The class name of the service class (fully qualified).
* @param string $serviceInterface The interface name of the service class returned (fully qualified).
* @param bool $isSingleton Set to true if the service instance requested is a singleton, default is false (you get a new instance each time).
*
* @throws \Alpha\Exception\IllegalArguementException
*
* @return \stdClass
*
* @since 3.0
*/
public static function getInstance($serviceName, $serviceInterface, $isSingleton = false)
{
// as the LogProviderInterface is itself a service, we don't call it's constructor again during instantiation
if (self::$logger === null && $serviceInterface != 'Alpha\Util\Logging\LogProviderInterface') {
self::$logger = new Logger('ServiceFactory');
}
if (self::$logger !== null) {
self::$logger->debug('>>getInstance(serviceName=['.$serviceName.'], serviceInterface=['.$serviceInterface.'], isSingleton=['.$isSingleton.'])');
}
if (class_exists($serviceName)) {
if ($isSingleton && in_array($serviceName, self::$singletons)) {
return self::$singletons[$serviceName];
}
$instance = new $serviceName();
if (!$instance instanceof $serviceInterface) {
throw new IllegalArguementException('The class ['.$serviceName.'] does not implement the expected ['.$serviceInterface.'] interface!');
}
if ($isSingleton && !in_array($serviceName, self::$singletons)) {
self::$singletons[$serviceName] = $instance;
}
if (self::$logger !== null) {
self::$logger->debug('<<getInstance: [Object '.$serviceName.']');
}
return $instance;
} else {
if (self::$logger !== null) {
self::$logger->debug('<<getInstance');
}
throw new IllegalArguementException('The class ['.$serviceName.'] is not defined anywhere!');
}
}
}