<?php

/*

* Copyright 2015 RhubarbPHP

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

namespace Rhubarb\Stem\Models;

use Rhubarb\Stem\Schema\SolutionSchema;

/**

* Co-ordinates events raised by models

*/

class ModelEventManager

{

public static function dispatchModelEvent($event, Model $model)

{

$event = SolutionSchema::getModelNameFromClass(get_class($model)) . ":" . $event;

if (!isset(self::$eventHandlers[$event])) {

return null;

}

$args = func_get_args();

$args = array_slice($args, 1);

// Check if the last argument is a callback.

$count = count($args);

$callBack = false;

if (($count > 0) && is_object($args[$count - 1]) && is_callable($args[$count - 1])) {

$callBack = $args[$count - 1];

$args = array_slice($args, 0, -1);

}

$result = null;

foreach (self::$eventHandlers[$event] as $delegate) {

$answer = call_user_func_array($delegate, $args);

if ($result === null) {

$result = $answer;

}

}

if ($callBack !== false) {

call_user_func($callBack, $result);

}

return $result;

}

private static $eventHandlers = array();

public static function attachEventHandler($modelName, $events, callable $delegate)

{

if (!is_array($events)) {

$eventsArray = [$events];

} else {

$eventsArray = $events;

}

foreach ($eventsArray as $event) {

if (!isset(self::$eventHandlers[$modelName . ":" . $event])) {

self::$eventHandlers[$modelName . ":" . $event] = array();

}

self::$eventHandlers[$modelName . ":" . $event][] = $delegate;

}

}

}