| 1 | <?php |
| 2 | /*************************************************************************** |
| 3 | * Copyright (C) 2003-2011 Polytechnique.org * |
| 4 | * http://opensource.polytechnique.org/ * |
| 5 | * * |
| 6 | * This program is free software; you can redistribute it and/or modify * |
| 7 | * it under the terms of the GNU General Public License as published by * |
| 8 | * the Free Software Foundation; either version 2 of the License, or * |
| 9 | * (at your option) any later version. * |
| 10 | * * |
| 11 | * This program is distributed in the hope that it will be useful, * |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
| 14 | * GNU General Public License for more details. * |
| 15 | * * |
| 16 | * You should have received a copy of the GNU General Public License * |
| 17 | * along with this program; if not, write to the Free Software * |
| 18 | * Foundation, Inc., * |
| 19 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * |
| 20 | ***************************************************************************/ |
| 21 | |
| 22 | class Visibility |
| 23 | { |
| 24 | /** Visibility levels. |
| 25 | * The VIEW_* constants describe the access level |
| 26 | * The EXPORT_* constants describe the degree of confidentiality of the data. |
| 27 | */ |
| 28 | const VIEW_NONE = 'none'; |
| 29 | const VIEW_PUBLIC = 'public'; |
| 30 | const VIEW_AX = 'ax'; |
| 31 | const VIEW_PRIVATE = 'private'; |
| 32 | const VIEW_ADMIN = 'admin'; |
| 33 | |
| 34 | const EXPORT_PUBLIC = 'public'; |
| 35 | const EXPORT_AX = 'ax'; |
| 36 | const EXPORT_PRIVATE = 'private'; |
| 37 | const EXPORT_HIDDEN = 'hidden'; |
| 38 | |
| 39 | /** Map each VIEW_ level to the list of EXPORT_ levels it can view. |
| 40 | */ |
| 41 | static private $view_levels = array( |
| 42 | self::VIEW_NONE => array(), |
| 43 | self::VIEW_PUBLIC => array(self::EXPORT_PUBLIC), |
| 44 | self::VIEW_AX => array(self::EXPORT_AX, self::EXPORT_PUBLIC), |
| 45 | self::VIEW_PRIVATE => array(self::EXPORT_PRIVATE, self::EXPORT_AX, self::EXPORT_PUBLIC), |
| 46 | self::VIEW_ADMIN => array(self::EXPORT_HIDDEN, self::EXPORT_PRIVATE, self::EXPORT_AX, self::EXPORT_PUBLIC), |
| 47 | ); |
| 48 | |
| 49 | static private $display_levels = array( |
| 50 | self::EXPORT_PUBLIC => 0, |
| 51 | self::EXPORT_AX => 1, |
| 52 | self::EXPORT_PRIVATE => 2, |
| 53 | self::EXPORT_HIDDEN => 3, |
| 54 | ); |
| 55 | |
| 56 | private $level; |
| 57 | |
| 58 | private function __construct($level) |
| 59 | { |
| 60 | $this->level = $level; |
| 61 | } |
| 62 | |
| 63 | static private $vis_list = array(); |
| 64 | public static function get($level) |
| 65 | { |
| 66 | Platal::assert(array_key_exists($level, self::$view_levels), "Invalid visibility access level $level."); |
| 67 | if (!array_key_exists($level, self::$vis_list)) { |
| 68 | self::$vis_list[$level] = new Visibility($level); |
| 69 | } |
| 70 | return self::$vis_list[$level]; |
| 71 | } |
| 72 | |
| 73 | public function level() |
| 74 | { |
| 75 | return $this->level; |
| 76 | } |
| 77 | |
| 78 | public static function defaultForRead($max_level = null) |
| 79 | { |
| 80 | if (!S::logged()) { |
| 81 | $vis = self::get(self::VIEW_PUBLIC); |
| 82 | } else { |
| 83 | $vis = S::user()->readVisibility(); |
| 84 | } |
| 85 | if ($max_level != null) { |
| 86 | return $vis->restrict($max_level); |
| 87 | } else { |
| 88 | return $vis; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | public static function defaultForEdit($max_level = null) |
| 93 | { |
| 94 | if (!S::logged()) { |
| 95 | $vis = self::get(self::VIEW_NONE); |
| 96 | } else { |
| 97 | $vis = S::user()->editVisibility(); |
| 98 | } |
| 99 | if ($max_level != null) { |
| 100 | return $vis->restrict($max_level); |
| 101 | } else { |
| 102 | return $vis; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /** Retrieve a 'restricted' version of the current Visibility. |
| 107 | * |
| 108 | * @param $level The visibility level to restrict to |
| 109 | * @return A new Visibility instance, whose level is min($this->level, $level) |
| 110 | */ |
| 111 | public function restrict($level = null) |
| 112 | { |
| 113 | if ($level != null && !$this->isVisible($level)) { |
| 114 | $level = $this->level(); |
| 115 | } |
| 116 | |
| 117 | return self::get($level); |
| 118 | } |
| 119 | |
| 120 | public function isVisible($visibility) |
| 121 | { |
| 122 | return in_array($visibility, self::$view_levels[$this->level()]); |
| 123 | } |
| 124 | |
| 125 | public function equals($visibility) |
| 126 | { |
| 127 | return $visibility !== null && $this->level() == $visibility->level(); |
| 128 | } |
| 129 | |
| 130 | static public function isLessRestrictive($level_a, $level_b) |
| 131 | { |
| 132 | // self::$display_levels is order from least restrictive |
| 133 | // to most restrictive. |
| 134 | return self::$display_levels[$level_a] >= self::$display_levels[$level_b]; |
| 135 | } |
| 136 | |
| 137 | /** Compare the visibility of two fields. |
| 138 | * Returns: |
| 139 | * >0 if $a is less restrictive than $b, |
| 140 | * <0 if $a is more restrictive than $b, |
| 141 | * 0 if $a is equal to $b. |
| 142 | */ |
| 143 | static public function cmpLessRestrictive($a, $b) |
| 144 | { |
| 145 | $a_pub = self::$display_levels[$a]; |
| 146 | $b_pub = self::$display_levels[$b]; |
| 147 | /* self::$display_levels is ordered from least restrictive to |
| 148 | * most restrictive. |
| 149 | * This will be 0 if both levels are equal, < 0 if $b_pub is less |
| 150 | * than $a_pub, thus less restrictive, which means that $a comes |
| 151 | * before $b in descending restrictiveness order. |
| 152 | */ |
| 153 | return $b_pub - $a_pub; |
| 154 | } |
| 155 | |
| 156 | static public function comparePublicity($a, $b) |
| 157 | { |
| 158 | return self::cmpLessRestrictive($a['pub'], $b['pub']); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8: |
| 163 | ?> |