includes/preferences/TimezoneFilter.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 namespace MediaWiki\Preferences;
  22
  23 use DateTimeZone;
  24 use Exception;
  25
  26 class TimezoneFilter implements Filter {
  27
  28         /**
  29          * @inheritDoc
  30          */
  31         public function filterForForm( $value ) {
  32                 return $value;
  33         }
  34
  35         /**
  36          * @inheritDoc
  37          */
  38         public function filterFromForm( $tz ) {
  39                 $data = explode( '|', $tz, 3 );
  40                 switch ( $data[0] ) {
  41                         case 'ZoneInfo':
  42                                 $valid = false;
  43
  44                                 if ( count( $data ) === 3 ) {
  45                                         // Make sure this timezone exists
  46                                         try {
  47                                                 new DateTimeZone( $data[2] );
  48                                                 // If the constructor didn't throw, we know it's valid
  49                                                 $valid = true;
  50                                         } catch ( Exception $e ) {
  51                                                 // Not a valid timezone
  52                                         }
  53                                 }
  54
  55                                 if ( !$valid ) {
  56                                         // If the supplied timezone doesn't exist, fall back to the encoded offset
  57                                         return 'Offset|' . intval( $tz[1] );
  58                                 }
  59                                 return $tz;
  60                         case 'System':
  61                                 return $tz;
  62                         default:
  63                                 $data = explode( ':', $tz, 2 );
  64                                 if ( count( $data ) == 2 ) {
  65                                         $data[0] = intval( $data[0] );
  66                                         $data[1] = intval( $data[1] );
  67                                         $minDiff = abs( $data[0] ) * 60 + $data[1];
  68                                         if ( $data[0] < 0 ) {
  69                                                 $minDiff = - $minDiff;
  70                                         }
  71                                 } else {
  72                                         $minDiff = intval( $data[0] ) * 60;
  73                                 }
  74
  75                                 # Max is +14:00 and min is -12:00, see:
  76                                 # https://en.wikipedia.org/wiki/Timezone
  77                                 # 14:00
  78                                 $minDiff = min( $minDiff, 840 );
  79                                 # -12:00
  80                                 $minDiff = max( $minDiff, -720 );
  81                                 return 'Offset|' . $minDiff;
  82                 }
  83         }
  84 }