includes/libs/ScopedCallback.php

   1 <?php
   2 /**
   3  * This file deals with RAII style scoped callbacks.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Class for asserting that a callback happens when an dummy object leaves scope
  25  *
  26  * @since 1.21
  27  */
  28 class ScopedCallback {
  29         /** @var callable */
  30         protected $callback;
  31         /** @var array */
  32         protected $params;
  33
  34         /**
  35          * @param callable|null $callback
  36          * @param array $params Callback arguments (since 1.25)
  37          * @throws Exception
  38          */
  39         public function __construct( $callback, array $params = array() ) {
  40                 if ( $callback !== null && !is_callable( $callback ) ) {
  41                         throw new InvalidArgumentException( "Provided callback is not valid." );
  42                 }
  43                 $this->callback = $callback;
  44                 $this->params = $params;
  45         }
  46
  47         /**
  48          * Trigger a scoped callback and destroy it.
  49          * This is the same is just setting it to null.
  50          *
  51          * @param ScopedCallback $sc
  52          */
  53         public static function consume( ScopedCallback &$sc = null ) {
  54                 $sc = null;
  55         }
  56
  57         /**
  58          * Destroy a scoped callback without triggering it
  59          *
  60          * @param ScopedCallback $sc
  61          */
  62         public static function cancel( ScopedCallback &$sc = null ) {
  63                 if ( $sc ) {
  64                         $sc->callback = null;
  65                 }
  66                 $sc = null;
  67         }
  68
  69         /**
  70          * Trigger the callback when this leaves scope
  71          */
  72         function __destruct() {
  73                 if ( $this->callback !== null ) {
  74                         call_user_func_array( $this->callback, $this->params );
  75                 }
  76         }
  77 }