1 | <?php |
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2 | /** |
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3 | * The RecordLock:: class provides a system for locking abstract DB rows. |
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4 | * |
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5 | * @author Quinn Comendant <quinn@strangecode.com> |
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6 | * @version 2.0 |
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7 | */ |
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8 | class RecordLock { |
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9 | |
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10 | // Configuration of this object. |
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11 | var $_params = array( |
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12 | 'timeout' => 600, |
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13 | 'auto_timeout' => 1800, |
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14 | 'error_url' => '/lock.php', |
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15 | 'db_table' => 'lock_tbl', |
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16 | 'create_table' => true, // Automatically create table and verify columns. Better set to false after site launch. |
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17 | ); |
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18 | |
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19 | // Store lock data from DB. |
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20 | var $data = array(); |
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21 | |
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22 | // Auth_SQL object from which to access a current user_id. |
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23 | var $_auth; |
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24 | |
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25 | /** |
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26 | * This method enforces the singleton pattern for this class. |
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27 | * |
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28 | * @return object Reference to the global RecordLock object. |
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29 | * @access public |
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30 | * @static |
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31 | */ |
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32 | function &getInstance($auth_object) |
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33 | { |
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34 | static $instances = array(); |
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35 | |
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36 | if (!is_a($auth_object, 'Auth_SQL')) { |
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37 | trigger_error('Constructor not provided a valid Auth_SQL object.', E_USER_ERROR); |
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38 | } |
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39 | |
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40 | if (!isset($instances[$auth_object->getVal('auth_name')])) { |
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41 | $instances[$auth_object->getVal('auth_name')] = new RecordLock($auth_object); |
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42 | } |
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43 | |
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44 | return $instances[$auth_object->getVal('auth_name')]; |
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45 | } |
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46 | |
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47 | /** |
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48 | * Constructor. Pass an Auth object on which to perform user lookups. |
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49 | * |
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50 | * @param mixed $auth_object An Auth_SQL object. |
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51 | */ |
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52 | function RecordLock($auth_object) |
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53 | { |
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54 | $this->_auth = $auth_object; |
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55 | |
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56 | // Get create tables config from global context. |
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57 | if (!is_null(App::getParam('db_create_tables'))) { |
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58 | $this->setParam(array('create_table' => App::getParam('db_create_tables'))); |
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59 | } |
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60 | } |
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61 | |
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62 | /** |
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63 | * Setup the database table for this class. |
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64 | * |
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65 | * @access public |
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66 | * @author Quinn Comendant <quinn@strangecode.com> |
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67 | * @since 26 Aug 2005 17:09:36 |
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68 | */ |
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69 | function initDB($recreate_db=false) |
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70 | { |
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71 | static $_db_tested = false; |
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72 | |
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73 | if ($recreate_db || !$_db_tested && $this->getParam('create_table')) { |
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74 | if ($recreate_db) { |
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75 | DB::query("DROP TABLE IF EXISTS " . $this->getParam('db_table')); |
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76 | App::logMsg(sprintf('Dropping and recreating table %s.', $this->getParam('db_table')), LOG_DEBUG, __FILE__, __LINE__); |
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77 | } |
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78 | DB::query("CREATE TABLE IF NOT EXISTS " . $this->getParam('db_table') . " ( |
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79 | lock_id int NOT NULL auto_increment, |
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80 | record_table varchar(255) NOT NULL default '', |
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81 | record_key varchar(255) NOT NULL default '', |
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82 | record_val varchar(255) NOT NULL default '', |
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83 | title varchar(255) NOT NULL default '', |
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84 | set_by_admin_id smallint(11) NOT NULL default '0', |
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85 | lock_datetime datetime NOT NULL default '0000-00-00 00:00:00', |
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86 | PRIMARY KEY (lock_id), |
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87 | KEY record_table (record_table), |
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88 | KEY record_key (record_key), |
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89 | KEY record_val (record_val) |
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90 | )"); |
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91 | |
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92 | if (!DB::columnExists($this->getParam('db_table'), array( |
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93 | 'lock_id', |
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94 | 'record_table', |
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95 | 'record_key', |
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96 | 'record_val', |
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97 | 'title', |
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98 | 'set_by_admin_id', |
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99 | 'lock_datetime', |
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100 | ), false, false)) { |
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101 | App::logMsg(sprintf('Database table %s has invalid columns. Please update this table manually.', $this->getParam('db_table')), LOG_ALERT, __FILE__, __LINE__); |
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102 | trigger_error(sprintf('Database table %s has invalid columns. Please update this table manually.', $this->getParam('db_table')), E_USER_ERROR); |
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103 | } |
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104 | } |
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105 | $_db_tested = true; |
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106 | } |
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107 | |
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108 | /** |
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109 | * Set the params of this object. |
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110 | * |
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111 | * @param array $params Array of param keys and values to set. |
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112 | */ |
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113 | function setParam($params=null) |
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114 | { |
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115 | if (isset($params) && is_array($params)) { |
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116 | // Merge new parameters with old overriding only those passed. |
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117 | $this->_params = array_merge($this->_params, $params); |
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118 | } |
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119 | } |
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120 | |
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121 | /** |
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122 | * Return the value of a param setting. |
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123 | * |
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124 | * @access public |
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125 | * @param string $params Which param to return. |
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126 | * @return mixed Configured param value. |
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127 | */ |
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128 | function getParam($param) |
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129 | { |
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130 | if (isset($this->_params[$param])) { |
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131 | return $this->_params[$param]; |
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132 | } else { |
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133 | App::logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__); |
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134 | return null; |
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135 | } |
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136 | } |
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137 | |
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138 | /** |
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139 | * Select the lock to manipulate. |
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140 | * |
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141 | * @param mixed $record_table_or_lock_id The table containing the record to lock, |
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142 | * or a numeric lock_id. |
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143 | * @param string $record_key The key column for the record to lock. |
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144 | * @param string $record_val The value of the key column for the record to lock. |
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145 | * @param string $title A title to apply to the lock, for display purposes. |
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146 | */ |
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147 | function select($record_table_or_lock_id, $record_key=null, $record_val=null) |
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148 | { |
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149 | $this->initDB(); |
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150 | |
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151 | // Expire old locks. |
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152 | $this->_auto_timeout(); |
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153 | |
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154 | if (is_numeric($record_table_or_lock_id) && !isset($record_key) && !isset($record_val)) { |
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155 | // Get lock data by lock_id. |
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156 | $qid = DB::query(" |
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157 | SELECT * FROM " . $this->getParam('db_table') . " |
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158 | WHERE lock_id = '" . addslashes($record_table_or_lock_id) . "' |
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159 | "); |
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160 | } else { |
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161 | // Get lock data by record specs |
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162 | $qid = DB::query(" |
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163 | SELECT * FROM " . $this->getParam('db_table') . " |
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164 | WHERE record_table = '" . addslashes($record_table_or_lock_id) . "' |
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165 | AND record_key = '" . addslashes($record_key) . "' |
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166 | AND record_val = '" . addslashes($record_val) . "' |
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167 | "); |
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168 | } |
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169 | if ($this->data = mysql_fetch_assoc($qid)) { |
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170 | App::logMsg(sprintf('Found locked record: %s %s %s', $record_table_or_lock_id, $record_key, $record_val), LOG_DEBUG, __FILE__, __LINE__); |
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171 | $this->data['editor'] = $this->_auth->getUsername($this->data['set_by_admin_id']); |
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172 | return true; |
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173 | } else { |
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174 | App::logMsg(sprintf('No locked record: %s %s %s', $record_table_or_lock_id, $record_key, $record_val), LOG_DEBUG, __FILE__, __LINE__); |
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175 | return false; |
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176 | } |
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177 | } |
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178 | |
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179 | /** |
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180 | * Returns true if the record we instantiated with is locked. |
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181 | * |
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182 | * @return bool True if locked. |
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183 | */ |
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184 | function isLocked() |
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185 | { |
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186 | return isset($this->data['lock_id']); |
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187 | } |
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188 | |
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189 | /** |
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190 | * Returns the status of who set the lock. Use this to ignore locks set by |
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191 | * the current user. |
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192 | * |
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193 | * @return bool True if current user set the lock. |
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194 | */ |
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195 | function isMine() |
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196 | { |
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197 | $this->initDB(); |
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198 | |
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199 | if (isset($this->data['lock_id'])) { |
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200 | $qid = DB::query("SELECT * FROM " . $this->getParam('db_table') . " WHERE lock_id = '" . addslashes($this->data['lock_id']) . "'"); |
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201 | if ($lock = mysql_fetch_assoc($qid)) { |
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202 | return ($lock['set_by_admin_id'] == $this->_auth->getVal('user_id')); |
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203 | } else { |
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204 | return false; |
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205 | } |
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206 | } else { |
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207 | return false; |
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208 | } |
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209 | } |
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210 | |
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211 | /** |
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212 | * Create a new lock for the specified table/key/value. |
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213 | * |
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214 | * @param string $record_table The table containing the record to lock. |
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215 | * @param string $record_key The key column for the record to lock. |
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216 | * @param string $record_val The value of the key column for the record to lock. |
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217 | * @param string $title A title to apply to the lock, for display purposes. |
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218 | * |
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219 | * @return int The id for the lock (mysql last insert id). |
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220 | */ |
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221 | function set($record_table, $record_key, $record_val, $title='') |
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222 | { |
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223 | $this->initDB(); |
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224 | |
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225 | // Expire old locks. |
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226 | $this->_auto_timeout(); |
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227 | |
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228 | // Remove previous locks if exist. Is this better than using a REPLACE INTO? |
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229 | DB::query(" |
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230 | DELETE FROM " . $this->getParam('db_table') . " |
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231 | WHERE record_table = '" . addslashes($record_table) . "' |
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232 | AND record_key = '" . addslashes($record_key) . "' |
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233 | AND record_val = '" . addslashes($record_val) . "' |
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234 | "); |
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235 | |
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236 | // Set new lock. |
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237 | DB::query(" |
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238 | INSERT INTO " . $this->getParam('db_table') . " ( |
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239 | record_table, |
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240 | record_key, |
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241 | record_val, |
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242 | title, |
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243 | set_by_admin_id, |
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244 | lock_datetime |
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245 | ) VALUES ( |
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246 | '" . addslashes($record_table) . "', |
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247 | '" . addslashes($record_key) . "', |
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248 | '" . addslashes($record_val) . "', |
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249 | '" . addslashes($title) . "', |
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250 | '" . addslashes($this->_auth->getVal('user_id')) . "', |
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251 | NOW() |
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252 | ) |
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253 | "); |
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254 | $lock_id = mysql_insert_id(DB::getDBH()); |
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255 | |
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256 | // Must register this locked record as the current. |
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257 | $this->select($lock_id); |
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258 | |
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259 | return $lock_id; |
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260 | } |
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261 | |
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262 | /** |
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263 | * Unlock the currently selected record. |
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264 | */ |
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265 | function remove() |
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266 | { |
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267 | $this->initDB(); |
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268 | |
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269 | // Expire old locks. |
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270 | $this->_auto_timeout(); |
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271 | |
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272 | // Delete a specific lock. |
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273 | DB::query(" |
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274 | DELETE FROM " . $this->getParam('db_table') . " |
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275 | WHERE lock_id = '" . addslashes($this->data['lock_id']) . "' |
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276 | "); |
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277 | } |
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278 | |
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279 | /** |
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280 | * Unlock all records, or all records for a specified user. |
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281 | */ |
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282 | function removeAll($user_id=null) |
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283 | { |
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284 | $this->initDB(); |
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285 | |
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286 | // Expire old locks. |
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287 | $this->_auto_timeout(); |
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288 | |
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289 | if (isset($user_id)) { |
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290 | // Delete specific user's locks. |
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291 | DB::query("DELETE FROM " . $this->getParam('db_table') . " WHERE set_by_admin_id = '" . addslashes($user_id) . "'"); |
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292 | App::logMsg(sprintf('Record locks owned by %s %s have been deleted', $this->_auth->getVal('auth_name'), $this->_auth->getUsername($user_id)), LOG_INFO, __FILE__, __LINE__); |
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293 | } else { |
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294 | // Delete ALL locks. |
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295 | DB::query("DELETE FROM " . $this->getParam('db_table') . ""); |
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296 | App::logMsg(sprintf('All record locks deleted by %s %s', $this->_auth->getVal('auth_name'), $this->_auth->getVal('username')), LOG_DEBUG, __FILE__, __LINE__); |
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297 | } |
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298 | } |
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299 | |
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300 | /** |
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301 | * Delete's all locks that are older than auto_timeout. |
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302 | */ |
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303 | function _auto_timeout() |
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304 | { |
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305 | static $_timeout_run = false; |
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306 | |
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307 | $this->initDB(); |
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308 | |
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309 | if (!$_timeout_run) { |
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310 | // Delete all old locks. |
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311 | DB::query(" |
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312 | DELETE FROM " . $this->getParam('db_table') . " |
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313 | WHERE DATE_ADD(lock_datetime, INTERVAL '" . $this->getParam('auto_timeout') . "' SECOND) < NOW() |
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314 | "); |
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315 | $_timeout_run = true; |
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316 | } |
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317 | } |
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318 | |
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319 | /** |
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320 | * Redirect to record lock error page. |
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321 | */ |
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322 | function dieErrorPage() |
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323 | { |
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324 | App::dieURL(sprintf('%s?lock_id=%s&boomerang=%s', $this->getParam('error_url'), $this->data['lock_id'], urlencode(absoluteMe()))); |
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325 | } |
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326 | |
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327 | /** |
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328 | * Print error page. |
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329 | */ |
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330 | function printErrorHTML() |
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331 | { |
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332 | ?> |
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333 | <form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> |
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334 | <?php App::printHiddenSession() ?> |
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335 | <input type="hidden" name="lock_id" value="<?php echo $this->getID(); ?>" /> |
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336 | |
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337 | <p><?php |
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338 | printf(_("The record <strong>%s</strong> is currently being edited by <strong>%s</strong> (%d minutes elapsed). You cannot modify the record while it is locked by another user."), |
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339 | $this->getTitle(), |
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340 | $this->getEditor(), |
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341 | date('i', $this->getSecondsElapsed() + 60) |
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342 | ); |
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343 | ?></p> |
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344 | |
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345 | <?php if ($this->getSecondsElapsed() > $this->getParam('timeout')) { ?> |
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346 | <p><?php printf(_("You can forcibly unlock the record if you believe the editing session has expired. You might want to confirm with %s before doing this."), $this->getEditor()) ?></p> |
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347 | <input type="submit" class="formsubmitbutton" name="unlock" value="<?php echo _("Unlock"); ?>"> |
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348 | <?php } ?> |
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349 | |
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350 | <input type="submit" class="formsubmitbutton" name="cancel" value="<?php echo _("Cancel"); ?>"> |
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351 | </form> |
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352 | <?php |
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353 | } |
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354 | |
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355 | /** |
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356 | * Return lock_id of locked record. |
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357 | */ |
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358 | function getID() |
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359 | { |
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360 | return $this->data['lock_id']; |
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361 | } |
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362 | |
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363 | /** |
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364 | * Return title of locked record. |
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365 | */ |
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366 | function getTitle() |
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367 | { |
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368 | return $this->data['title']; |
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369 | } |
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370 | |
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371 | /** |
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372 | * Return administrator username for locked record. |
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373 | */ |
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374 | function getEditor() |
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375 | { |
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376 | return $this->data['editor']; |
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377 | } |
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378 | |
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379 | /** |
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380 | * Return total seconds since the record was locked. |
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381 | */ |
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382 | function getSecondsElapsed() |
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383 | { |
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384 | if (isset($this->data['lock_datetime']) && $this->data['lock_datetime'] < time()) { |
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385 | return time() - strtotime($this->data['lock_datetime']); |
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386 | } else { |
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387 | return 0; |
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388 | } |
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389 | } |
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390 | |
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391 | |
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392 | } // End of class. |
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393 | ?> |
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