1 | <?php |
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2 | /** |
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3 | * Lock.inc.php |
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4 | * code by strangecode :: www.strangecode.com :: this document contains copyrighted information |
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5 | * |
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6 | * The Lock class provides a system for locking abstract DB rows. |
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7 | * |
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8 | * @author Quinn Comendant <quinn@strangecode.com> |
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9 | * @version 2.1 |
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10 | */ |
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11 | class Lock { |
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12 | |
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13 | // Configuration of this object. |
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14 | var $_params = array( |
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15 | 'timeout' => 600, |
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16 | 'auto_timeout' => 1800, |
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17 | 'error_url' => '/lock.php', |
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18 | 'db_table' => 'lock_tbl', |
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19 | |
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20 | // Automatically create table and verify columns. Better set to false after site launch. |
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21 | 'create_table' => true, |
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22 | ); |
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23 | |
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24 | // Store lock data from DB. |
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25 | var $data = array(); |
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26 | |
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27 | // Auth_SQL object from which to access a current user_id. |
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28 | var $_auth; |
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29 | |
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30 | /** |
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31 | * This method enforces the singleton pattern for this class. |
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32 | * |
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33 | * @return object Reference to the global Lock object. |
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34 | * @access public |
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35 | * @static |
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36 | */ |
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37 | function &getInstance($auth_object) |
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38 | { |
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39 | static $instance = null; |
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40 | |
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41 | if ($instance === null) { |
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42 | $instance = new Lock($auth_object); |
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43 | } |
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44 | |
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45 | return $instance; |
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46 | } |
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47 | |
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48 | /** |
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49 | * Constructor. Pass an Auth object on which to perform user lookups. |
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50 | * |
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51 | * @param mixed $auth_object An Auth_SQL or Auth_FILE object. |
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52 | */ |
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53 | function Lock($auth_object) |
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54 | { |
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55 | $app =& App::getInstance(); |
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56 | |
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57 | if (!method_exists($auth_object, 'get') || !method_exists($auth_object, 'getUsername')) { |
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58 | trigger_error('Constructor not provided a valid Auth_* object.', E_USER_ERROR); |
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59 | } |
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60 | |
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61 | $this->_auth = $auth_object; |
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62 | |
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63 | // Get create tables config from global context. |
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64 | if (!is_null($app->getParam('db_create_tables'))) { |
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65 | $this->setParam(array('create_table' => $app->getParam('db_create_tables'))); |
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66 | } |
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67 | } |
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68 | |
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69 | /** |
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70 | * Setup the database table for this class. |
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71 | * |
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72 | * @access public |
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73 | * @author Quinn Comendant <quinn@strangecode.com> |
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74 | * @since 26 Aug 2005 17:09:36 |
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75 | */ |
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76 | function initDB($recreate_db=false) |
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77 | { |
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78 | $app =& App::getInstance(); |
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79 | $db =& DB::getInstance(); |
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80 | |
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81 | static $_db_tested = false; |
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82 | |
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83 | if ($recreate_db || !$_db_tested && $this->getParam('create_table')) { |
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84 | if ($recreate_db) { |
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85 | $db->query("DROP TABLE IF EXISTS " . $this->getParam('db_table')); |
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86 | $app->logMsg(sprintf('Dropping and recreating table %s.', $this->getParam('db_table')), LOG_INFO, __FILE__, __LINE__); |
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87 | } |
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88 | $db->query("CREATE TABLE IF NOT EXISTS " . $db->escapeString($this->getParam('db_table')) . " ( |
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89 | lock_id int NOT NULL auto_increment, |
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90 | record_table varchar(255) NOT NULL default '', |
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91 | record_key varchar(255) NOT NULL default '', |
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92 | record_val varchar(255) NOT NULL default '', |
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93 | title varchar(255) NOT NULL default '', |
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94 | set_by_admin_id smallint(11) NOT NULL default '0', |
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95 | lock_datetime datetime NOT NULL default '0000-00-00 00:00:00', |
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96 | PRIMARY KEY (lock_id), |
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97 | KEY record_table (record_table), |
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98 | KEY record_key (record_key), |
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99 | KEY record_val (record_val) |
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100 | )"); |
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101 | |
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102 | if (!$db->columnExists($this->getParam('db_table'), array( |
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103 | 'lock_id', |
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104 | 'record_table', |
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105 | 'record_key', |
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106 | 'record_val', |
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107 | 'title', |
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108 | 'set_by_admin_id', |
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109 | 'lock_datetime', |
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110 | ), false, false)) { |
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111 | $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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112 | 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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113 | } |
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114 | } |
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115 | $_db_tested = true; |
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116 | } |
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117 | |
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118 | /** |
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119 | * Set the params of this object. |
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120 | * |
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121 | * @param array $params Array of param keys and values to set. |
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122 | */ |
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123 | function setParam($params=null) |
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124 | { |
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125 | if (isset($params) && is_array($params)) { |
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126 | // Merge new parameters with old overriding only those passed. |
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127 | $this->_params = array_merge($this->_params, $params); |
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128 | } |
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129 | } |
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130 | |
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131 | /** |
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132 | * Return the value of a parameter, if it exists. |
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133 | * |
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134 | * @access public |
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135 | * @param string $param Which parameter to return. |
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136 | * @return mixed Configured parameter value. |
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137 | */ |
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138 | function getParam($param) |
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139 | { |
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140 | $app =& App::getInstance(); |
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141 | |
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142 | if (isset($this->_params[$param])) { |
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143 | return $this->_params[$param]; |
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144 | } else { |
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145 | $app->logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__); |
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146 | return null; |
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147 | } |
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148 | } |
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149 | |
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150 | /** |
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151 | * Select the lock to manipulate. |
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152 | * |
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153 | * @param mixed $record_table_or_lock_id The table containing the record to lock, |
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154 | * or a numeric lock_id. |
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155 | * @param string $record_key The key column for the record to lock. |
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156 | * @param string $record_val The value of the key column for the record to lock. |
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157 | * @param string $title A title to apply to the lock, for display purposes. |
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158 | */ |
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159 | function select($record_table_or_lock_id, $record_key=null, $record_val=null) |
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160 | { |
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161 | $app =& App::getInstance(); |
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162 | $db =& DB::getInstance(); |
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163 | |
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164 | $this->initDB(); |
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165 | |
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166 | // Expire old locks. |
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167 | $this->_auto_timeout(); |
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168 | |
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169 | if (is_numeric($record_table_or_lock_id) && !isset($record_key) && !isset($record_val)) { |
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170 | // Get lock data by lock_id. |
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171 | $qid = $db->query(" |
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172 | SELECT * FROM " . $db->escapeString($this->getParam('db_table')) . " |
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173 | WHERE lock_id = '" . $db->escapeString($record_table_or_lock_id) . "' |
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174 | "); |
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175 | } else { |
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176 | // Get lock data by record specs |
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177 | $qid = $db->query(" |
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178 | SELECT * FROM " . $db->escapeString($this->getParam('db_table')) . " |
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179 | WHERE record_table = '" . $db->escapeString($record_table_or_lock_id) . "' |
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180 | AND record_key = '" . $db->escapeString($record_key) . "' |
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181 | AND record_val = '" . $db->escapeString($record_val) . "' |
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182 | "); |
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183 | } |
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184 | if ($this->data = mysql_fetch_assoc($qid)) { |
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185 | $app->logMsg(sprintf('Selecting %slocked record: %s %s %s', ($this->data['set_by_admin_id'] == $this->_auth->get('user_id') ? 'self-' : ''), $record_table_or_lock_id, $record_key, $record_val), LOG_DEBUG, __FILE__, __LINE__); |
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186 | /// FIX ME: What if admin set lock, but public user is current lock user? |
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187 | $this->data['editor'] = $this->_auth->getUsername($this->data['set_by_admin_id']); |
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188 | return true; |
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189 | } else { |
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190 | $app->logMsg(sprintf('No locked record: %s %s %s', $record_table_or_lock_id, $record_key, $record_val), LOG_DEBUG, __FILE__, __LINE__); |
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191 | return false; |
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192 | } |
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193 | } |
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194 | |
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195 | /** |
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196 | * Returns true if the record we instantiated with is locked. |
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197 | * |
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198 | * @return bool True if locked. |
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199 | */ |
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200 | function isLocked() |
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201 | { |
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202 | return isset($this->data['lock_id']); |
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203 | } |
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204 | |
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205 | /** |
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206 | * Returns the status of who set the lock. Use this to ignore locks set by |
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207 | * the current user. |
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208 | * |
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209 | * @return bool True if current user set the lock. |
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210 | */ |
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211 | function isMine() |
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212 | { |
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213 | $db =& DB::getInstance(); |
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214 | |
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215 | $this->initDB(); |
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216 | |
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217 | if (isset($this->data['lock_id'])) { |
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218 | $qid = $db->query("SELECT * FROM " . $db->escapeString($this->getParam('db_table')) . " WHERE lock_id = '" . $db->escapeString($this->data['lock_id']) . "'"); |
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219 | if ($lock = mysql_fetch_assoc($qid)) { |
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220 | return ($lock['set_by_admin_id'] == $this->_auth->get('user_id')); |
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221 | } else { |
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222 | return false; |
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223 | } |
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224 | } else { |
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225 | return false; |
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226 | } |
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227 | } |
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228 | |
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229 | /** |
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230 | * Create a new lock for the specified table/key/value. |
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231 | * |
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232 | * @param string $record_table The table containing the record to lock. |
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233 | * @param string $record_key The key column for the record to lock. |
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234 | * @param string $record_val The value of the key column for the record to lock. |
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235 | * @param string $title A title to apply to the lock, for display purposes. |
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236 | * |
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237 | * @return int The id for the lock (mysql last insert id). |
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238 | */ |
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239 | function set($record_table, $record_key, $record_val, $title='') |
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240 | { |
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241 | $db =& DB::getInstance(); |
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242 | |
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243 | $this->initDB(); |
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244 | |
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245 | // Expire old locks. |
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246 | $this->_auto_timeout(); |
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247 | |
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248 | // Remove previous locks if exist. Is this better than using a REPLACE INTO? |
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249 | $db->query(" |
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250 | DELETE FROM " . $db->escapeString($this->getParam('db_table')) . " |
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251 | WHERE record_table = '" . $db->escapeString($record_table) . "' |
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252 | AND record_key = '" . $db->escapeString($record_key) . "' |
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253 | AND record_val = '" . $db->escapeString($record_val) . "' |
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254 | "); |
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255 | |
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256 | // Set new lock. |
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257 | $db->query(" |
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258 | INSERT INTO " . $db->escapeString($this->getParam('db_table')) . " ( |
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259 | record_table, |
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260 | record_key, |
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261 | record_val, |
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262 | title, |
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263 | set_by_admin_id, |
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264 | lock_datetime |
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265 | ) VALUES ( |
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266 | '" . $db->escapeString($record_table) . "', |
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267 | '" . $db->escapeString($record_key) . "', |
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268 | '" . $db->escapeString($record_val) . "', |
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269 | '" . $db->escapeString($title) . "', |
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270 | '" . $db->escapeString($this->_auth->get('user_id')) . "', |
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271 | NOW() |
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272 | ) |
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273 | "); |
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274 | $lock_id = mysql_insert_id($db->getDBH()); |
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275 | |
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276 | // Must register this locked record as the current. |
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277 | $this->select($lock_id); |
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278 | |
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279 | return $lock_id; |
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280 | } |
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281 | |
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282 | /** |
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283 | * Unlock the currently selected record. |
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284 | */ |
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285 | function remove() |
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286 | { |
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287 | $app =& App::getInstance(); |
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288 | $db =& DB::getInstance(); |
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289 | |
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290 | $this->initDB(); |
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291 | |
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292 | // Expire old locks. |
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293 | $this->_auto_timeout(); |
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294 | |
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295 | // Delete a specific lock. |
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296 | $db->query(" |
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297 | DELETE FROM " . $db->escapeString($this->getParam('db_table')) . " |
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298 | WHERE lock_id = '" . $db->escapeString($this->data['lock_id']) . "' |
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299 | "); |
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300 | |
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301 | $app->logMsg(sprintf('Removing lock: %s', $this->data['lock_id']), LOG_DEBUG, __FILE__, __LINE__); |
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302 | } |
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303 | |
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304 | /** |
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305 | * Unlock all records, or all records for a specified user. |
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306 | */ |
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307 | function removeAll($user_id=null) |
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308 | { |
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309 | $app =& App::getInstance(); |
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310 | $db =& DB::getInstance(); |
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311 | |
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312 | $this->initDB(); |
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313 | |
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314 | // Expire old locks. |
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315 | $this->_auto_timeout(); |
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316 | |
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317 | if (isset($user_id)) { |
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318 | // Delete specific user's locks. |
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319 | $db->query("DELETE FROM " . $db->escapeString($this->getParam('db_table')) . " WHERE set_by_admin_id = '" . $db->escapeString($user_id) . "'"); |
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320 | $app->logMsg(sprintf('Record locks owned by user %s have been deleted', $this->_auth->getUsername($user_id)), LOG_DEBUG, __FILE__, __LINE__); |
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321 | } else { |
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322 | // Delete ALL locks. |
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323 | $db->query("DELETE FROM " . $db->escapeString($this->getParam('db_table')) . ""); |
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324 | $app->logMsg(sprintf('All record locks deleted by user %s', $this->_auth->get('username')), LOG_DEBUG, __FILE__, __LINE__); |
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325 | } |
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326 | } |
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327 | |
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328 | /** |
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329 | * Delete's all locks that are older than auto_timeout. |
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330 | */ |
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331 | function _auto_timeout() |
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332 | { |
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333 | $db =& DB::getInstance(); |
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334 | |
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335 | static $_timeout_run = false; |
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336 | |
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337 | $this->initDB(); |
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338 | |
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339 | if (!$_timeout_run) { |
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340 | // Delete all old locks. |
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341 | $db->query(" |
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342 | DELETE FROM " . $db->escapeString($this->getParam('db_table')) . " |
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343 | WHERE DATE_ADD(lock_datetime, INTERVAL '" . $this->getParam('auto_timeout') . "' SECOND) < NOW() |
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344 | "); |
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345 | $_timeout_run = true; |
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346 | } |
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347 | } |
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348 | |
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349 | /** |
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350 | * Redirect to record lock error page. |
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351 | */ |
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352 | function dieErrorPage() |
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353 | { |
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354 | $app =& App::getInstance(); |
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355 | |
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356 | $app->dieURL(sprintf('%s?lock_id=%s&boomerang=%s', $this->getParam('error_url'), $this->data['lock_id'], urlencode(absoluteMe()))); |
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357 | } |
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358 | |
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359 | /** |
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360 | * Print error page. |
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361 | */ |
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362 | function printErrorHTML() |
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363 | { |
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364 | $app =& App::getInstance(); |
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365 | |
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366 | ?> |
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367 | <form method="post" action="<?php echo oTxt($_SERVER['PHP_SELF']); ?>"> |
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368 | <?php $app->printHiddenSession() ?> |
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369 | <input type="hidden" name="lock_id" value="<?php echo $this->getID(); ?>" /> |
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370 | |
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371 | <p><?php |
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372 | printf(_("The record %s is currently being edited by %s (%d minutes elapsed). You cannot modify the record while it is locked by another user."), |
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373 | $this->getTitle(), |
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374 | $this->getEditor(), |
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375 | date('i', $this->getSecondsElapsed() + 60) |
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376 | ); |
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377 | ?></p> |
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378 | |
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379 | <?php if ($this->getSecondsElapsed() > $this->getParam('timeout')) { ?> |
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380 | <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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381 | <input type="submit" name="unlock" value="<?php echo _("Unlock"); ?>" /> |
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382 | <?php } ?> |
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383 | |
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384 | <input type="submit" name="cancel" value="<?php echo _("Cancel"); ?>" /> |
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385 | </form> |
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386 | <?php |
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387 | } |
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388 | |
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389 | /** |
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390 | * Return lock_id of locked record. |
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391 | */ |
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392 | function getID() |
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393 | { |
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394 | return $this->data['lock_id']; |
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395 | } |
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396 | |
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397 | /** |
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398 | * Return title of locked record. |
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399 | */ |
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400 | function getTitle() |
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401 | { |
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402 | return $this->data['title']; |
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403 | } |
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404 | |
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405 | /** |
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406 | * Return administrator username for locked record. |
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407 | */ |
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408 | function getEditor() |
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409 | { |
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410 | return $this->data['editor']; |
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411 | } |
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412 | |
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413 | /** |
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414 | * Return total seconds since the record was locked. |
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415 | */ |
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416 | function getSecondsElapsed() |
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417 | { |
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418 | if (isset($this->data['lock_datetime']) && $this->data['lock_datetime'] < time()) { |
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419 | return time() - strtotime($this->data['lock_datetime']); |
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420 | } else { |
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421 | return 0; |
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422 | } |
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423 | } |
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424 | |
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425 | |
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426 | } // End of class. |
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427 | ?> |
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