1 | <?php |
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2 | /** |
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3 | * The RecordVersion:: class provides a system for saving, reviewing, and |
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4 | * restoring versions of a record of any DB table. All the data in the record is |
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5 | * serialized, compressed, and saved in a blob in the version_tbl. Restoring a |
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6 | * version simply does a REPLACE INTO of the data. It is very simple, and works |
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7 | * with multiple database tables, but the drawback is that relationships for |
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8 | * a record cannot be retained. For example, an article from an article_tbl can |
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9 | * be saved, but not categories associated to the record in a category_article_tbl. |
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10 | * The restored article will simple retain the relationships that the previous |
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11 | * current article had. |
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12 | * |
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13 | * @author Quinn Comendant <quinn@strangecode.com> |
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14 | * @version 2.1 |
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15 | */ |
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16 | |
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17 | class RecordVersion { |
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18 | |
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19 | // Configuration of this object. |
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20 | var $_params = array( |
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21 | 'max_qty' => 100, // Never have more than this many versions of each record. |
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22 | 'min_qty' => 25, // Keep at least this many versions of each record. |
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23 | 'min_days' => 7, // Keep ALL versions within this many days, even if MORE than min_qty. |
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24 | 'db_table' => 'version_tbl', |
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25 | 'create_table' => true, // Automatically create table and verify columns. Better set to false after site launch. |
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26 | 'db_schema_strict' => true, // If true, makes an exact comparison of saved vs. live table schemas. If false, just checks that the saved columns are available. |
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27 | ); |
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28 | |
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29 | // Auth_SQL object from which to access a current user_id. |
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30 | var $_auth; |
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31 | |
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32 | /** |
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33 | * This method enforces the singleton pattern for this class. |
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34 | * |
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35 | * @return object Reference to the global RecordVersion object. |
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36 | * @access public |
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37 | * @static |
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38 | */ |
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39 | function &getInstance($auth_object) |
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40 | { |
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41 | static $instances = array(); |
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42 | |
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43 | if (!isset($instances[$auth_object->getVal('auth_name')])) { |
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44 | $instances[$auth_object->getVal('auth_name')] = new RecordVersion($auth_object); |
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45 | } |
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46 | |
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47 | return $instances[$auth_object->getVal('auth_name')]; |
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48 | } |
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49 | |
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50 | /** |
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51 | * Constructor. Pass an Auth object on which to perform user lookups. |
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52 | * |
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53 | * @param mixed $auth_object An Auth_SQL object. |
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54 | */ |
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55 | function RecordVersion($auth_object) |
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56 | { |
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57 | if (!is_a($auth_object, 'Auth_SQL')) { |
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58 | trigger_error('Constructor not provided a valid Auth_SQL 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 | static $_db_tested = false; |
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79 | |
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80 | if ($recreate_db || !$_db_tested && $this->getParam('create_table')) { |
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81 | if ($recreate_db) { |
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82 | DB::query("DROP TABLE IF EXISTS " . $this->getParam('db_table')); |
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83 | App::logMsg(sprintf('Dropping and recreating table %s.', $this->getParam('db_table')), LOG_DEBUG, __FILE__, __LINE__); |
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84 | } |
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85 | DB::query("CREATE TABLE IF NOT EXISTS " . $this->getParam('db_table') . " ( |
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86 | version_id int NOT NULL auto_increment, |
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87 | record_table varchar(255) NOT NULL default '', |
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88 | record_key varchar(255) NOT NULL default '', |
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89 | record_val varchar(255) NOT NULL default '', |
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90 | version_data mediumblob NOT NULL, |
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91 | version_title varchar(255) NOT NULL default '', |
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92 | version_notes varchar(255) NOT NULL default '', |
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93 | saved_by_admin_id smallint(11) NOT NULL default '0', |
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94 | version_datetime datetime NOT NULL default '0000-00-00 00:00:00', |
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95 | PRIMARY KEY (version_id), |
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96 | KEY record_table (record_table), |
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97 | KEY record_key (record_key), |
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98 | KEY record_val (record_val) |
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99 | )"); |
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100 | |
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101 | if (!DB::columnExists($this->getParam('db_table'), array( |
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102 | 'version_id', |
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103 | 'record_table', |
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104 | 'record_key', |
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105 | 'record_val', |
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106 | 'version_data', |
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107 | 'version_title', |
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108 | 'version_notes', |
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109 | 'saved_by_admin_id', |
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110 | 'version_datetime', |
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111 | ), false, false)) { |
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112 | 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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113 | 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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114 | } |
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115 | } |
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116 | $_db_tested = true; |
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117 | } |
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118 | |
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119 | /** |
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120 | * Set the params of this object. |
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121 | * |
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122 | * @param array $params Array of param keys and values to set. |
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123 | */ |
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124 | function setParam($params=null) |
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125 | { |
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126 | if (isset($params) && is_array($params)) { |
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127 | // Merge new parameters with old overriding only those passed. |
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128 | $this->_params = array_merge($this->_params, $params); |
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129 | } |
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130 | } |
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131 | |
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132 | /** |
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133 | * Return the value of a param setting. |
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134 | * |
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135 | * @access public |
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136 | * @param string $params Which param to return. |
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137 | * @return mixed Configured param value. |
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138 | */ |
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139 | function getParam($param) |
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140 | { |
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141 | if (isset($this->_params[$param])) { |
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142 | return $this->_params[$param]; |
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143 | } else { |
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144 | App::logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__); |
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145 | return null; |
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146 | } |
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147 | } |
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148 | |
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149 | /** |
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150 | * Saves a version of the current record into the version table. |
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151 | * |
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152 | * @param string $record_table The table containing the record. |
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153 | * @param string $record_key The key column for the record. |
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154 | * @param string $record_val The value of the key column for the record. |
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155 | * @param string $title The title of this record. Only used for human presentation. |
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156 | * |
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157 | * @return int The id for the version (mysql last insert id). |
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158 | */ |
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159 | function create($record_table, $record_key, $record_val, $title='', $notes='') |
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160 | { |
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161 | $this->initDB(); |
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162 | |
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163 | // Get current record. |
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164 | if (!$record = $this->getCurrent($record_table, $record_key, $record_val)) { |
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165 | App::logMsg(sprintf('Could not create %s version, record not found: %s, %s, %s.', $title, $record_table, $record_key, $record_val), LOG_ERR, __FILE__, __LINE__); |
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166 | return false; |
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167 | } |
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168 | |
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169 | // Clean-up old versions. |
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170 | $this->deleteOld($record_table, $record_key, $record_val); |
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171 | |
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172 | // Save as new version. |
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173 | DB::query(" |
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174 | INSERT INTO " . $this->getParam('db_table') . " ( |
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175 | record_table, |
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176 | record_key, |
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177 | record_val, |
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178 | version_data, |
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179 | version_title, |
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180 | version_notes, |
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181 | saved_by_admin_id, |
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182 | version_datetime |
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183 | ) VALUES ( |
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184 | '" . DB::escapeString($record_table) . "', |
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185 | '" . DB::escapeString($record_key) . "', |
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186 | '" . DB::escapeString($record_val) . "', |
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187 | '" . DB::escapeString(gzcompress(serialize($record), 9)) . "', |
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188 | '" . DB::escapeString($title) . "', |
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189 | '" . DB::escapeString($notes) . "', |
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190 | '" . DB::escapeString($this->_auth->getVal('user_id')) . "', |
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191 | NOW() |
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192 | ) |
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193 | "); |
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194 | |
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195 | return mysql_insert_id(DB::getDBH()); |
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196 | } |
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197 | |
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198 | /** |
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199 | * Copy a version back into it's original table. |
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200 | * |
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201 | * @param string $version_id The id of the version to restore. |
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202 | * |
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203 | * @return int The id for the version (mysql last insert id). |
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204 | */ |
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205 | function restore($version_id) |
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206 | { |
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207 | $this->initDB(); |
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208 | |
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209 | // Get version data. |
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210 | $qid = DB::query(" |
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211 | SELECT * FROM " . $this->getParam('db_table') . " |
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212 | WHERE version_id = '" . DB::escapeString($version_id) . "' |
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213 | "); |
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214 | if (!$record = mysql_fetch_assoc($qid)) { |
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215 | App::raiseMsg(sprintf(_("Version ID %s%s not found."), $version_id, (empty($record['version_title']) ? '' : ' (' . $record['version_title'] . ')')), MSG_WARNING, __FILE__, __LINE__); |
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216 | App::logMsg(sprintf(_("Version ID %s%s not found."), $version_id, (empty($record['version_title']) ? '' : ' (' . $record['version_title'] . ')')), LOG_WARNING, __FILE__, __LINE__); |
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217 | return false; |
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218 | } |
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219 | $data = unserialize(gzuncompress($record['version_data'])); |
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220 | |
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221 | // Ensure saved db columns match current table schema. |
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222 | if (!DB::columnExists($record['record_table'], array_keys($data), $this->getParam('db_schema_strict'))) { |
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223 | App::raiseMsg(sprintf(_("Version ID %s%s is not compatible with the current database table."), $version_id, (empty($record['version_title']) ? '' : ' (' . $record['version_title'] . ')')), MSG_ERR, __FILE__, __LINE__); |
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224 | App::logMsg(sprintf(_("Version ID %s%s restoration failed, DB schema does not match for table %s."), $version_id, (empty($record['version_title']) ? '' : ' (' . $record['version_title'] . ')'), $record['record_table']), LOG_ALERT, __FILE__, __LINE__); |
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225 | return false; |
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226 | } |
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227 | |
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228 | // SQLize the keys of the specified versioned record. |
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229 | $replace_keys = join(",\n", array_map(array('DB', 'escapeString'), array_keys($data))); |
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230 | |
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231 | // SQLize the keys of the values of the specified versioned record. (These are more complex because we need to account for SQL null values.) |
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232 | $replace_values = ''; |
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233 | $comma = ''; |
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234 | foreach ($data as $v) { |
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235 | $replace_values .= is_null($v) ? "$comma\nNULL" : "$comma\n'" . DB::escapeString($v) . "'"; |
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236 | $comma = ','; |
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237 | } |
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238 | |
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239 | // Replace current record with specified versioned record. |
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240 | DB::query(" |
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241 | REPLACE INTO " . $record['record_table'] . " ( |
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242 | $replace_keys |
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243 | ) VALUES ( |
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244 | $replace_values |
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245 | ) |
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246 | "); |
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247 | |
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248 | return $record; |
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249 | } |
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250 | |
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251 | /** |
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252 | * Version garbage collection. Deletes versions older than min_days |
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253 | * when quantity of versions exceeds min_qty. If quantity |
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254 | * exceeds 100 within min_days, the oldest are deleted to bring the |
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255 | * quantity back down to min_qty. |
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256 | * |
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257 | * @param string $record_table The table containing the record. |
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258 | * @param string $record_key The key column for the record. |
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259 | * @param string $record_val The value of the key column for the record. |
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260 | * |
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261 | * @return mixed Array of versions, or false if none. |
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262 | */ |
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263 | function deleteOld($record_table, $record_key, $record_val) |
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264 | { |
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265 | $this->initDB(); |
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266 | |
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267 | // Get total number of versions for this record. |
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268 | $qid = DB::query(" |
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269 | SELECT COUNT(*) FROM " . $this->getParam('db_table') . " |
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270 | WHERE record_table = '" . DB::escapeString($record_table) . "' |
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271 | AND record_key = '" . DB::escapeString($record_key) . "' |
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272 | AND record_val = '" . DB::escapeString($record_val) . "' |
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273 | "); |
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274 | list($v_count) = mysql_fetch_row($qid); |
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275 | |
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276 | if ($v_count > $this->getParam('min_qty')) { |
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277 | if ($v_count > $this->getParam('max_qty')) { |
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278 | // To prevent a record bomb, limit max number of versions to max_qty. |
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279 | // First query for oldest records, selecting enough to bring total number down to min_qty. |
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280 | $qid = DB::query(" |
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281 | SELECT version_id FROM " . $this->getParam('db_table') . " |
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282 | WHERE record_table = '" . DB::escapeString($record_table) . "' |
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283 | AND record_key = '" . DB::escapeString($record_key) . "' |
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284 | AND record_val = '" . DB::escapeString($record_val) . "' |
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285 | ORDER BY version_datetime ASC |
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286 | LIMIT " . ($v_count - $this->getParam('min_qty')) . " |
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287 | "); |
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288 | while (list($old_id) = mysql_fetch_row($qid)) { |
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289 | $old_versions[] = $old_id; |
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290 | } |
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291 | DB::query(" |
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292 | DELETE FROM " . $this->getParam('db_table') . " |
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293 | WHERE version_id IN ('" . join("','", $old_versions) . "') |
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294 | "); |
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295 | } else { |
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296 | // Delete versions older than min_days, while still keeping min_qty. |
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297 | $qid = DB::query(" |
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298 | SELECT version_id FROM " . $this->getParam('db_table') . " |
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299 | WHERE record_table = '" . DB::escapeString($record_table) . "' |
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300 | AND record_key = '" . DB::escapeString($record_key) . "' |
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301 | AND record_val = '" . DB::escapeString($record_val) . "' |
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302 | AND DATE_ADD(version_datetime, INTERVAL '" . $this->getParam('min_days') . "' DAY) < NOW() |
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303 | ORDER BY version_datetime ASC |
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304 | LIMIT " . ($v_count - $this->getParam('min_qty')) . " |
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305 | "); |
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306 | while (list($old_id) = mysql_fetch_row($qid)) { |
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307 | $old_versions[] = $old_id; |
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308 | } |
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309 | if (sizeof($old_versions) > 0) { |
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310 | DB::query(" |
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311 | DELETE FROM " . $this->getParam('db_table') . " |
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312 | WHERE version_id IN ('" . join("','", $old_versions) . "') |
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313 | "); |
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314 | } |
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315 | } |
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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 | * Get a list of versions of specified record. |
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321 | * |
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322 | * @param string $record_table The table containing the record. |
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323 | * @param string $record_key The key column for the record. |
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324 | * @param string $record_val The value of the key column for the record. |
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325 | * |
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326 | * @return mixed Array of versions, or false if none. |
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327 | */ |
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328 | function getList($record_table, $record_key, $record_val) |
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329 | { |
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330 | $this->initDB(); |
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331 | |
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332 | // Get versions of this record. |
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333 | $qid = DB::query(" |
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334 | SELECT version_id, saved_by_admin_id, version_datetime, version_title |
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335 | FROM " . $this->getParam('db_table') . " |
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336 | WHERE record_table = '" . DB::escapeString($record_table) . "' |
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337 | AND record_key = '" . DB::escapeString($record_key) . "' |
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338 | AND record_val = '" . DB::escapeString($record_val) . "' |
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339 | ORDER BY version_datetime DESC |
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340 | "); |
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341 | $versions = array(); |
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342 | while ($row = mysql_fetch_assoc($qid)) { |
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343 | // Get admin usernames. |
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344 | $row['editor'] = $this->_auth->getVal('auth_type') . ' ' . $this->_auth->getUsername($row['saved_by_admin_id']); |
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345 | $versions[] = $row; |
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346 | } |
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347 | return $versions; |
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348 | } |
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349 | |
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350 | /** |
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351 | * Get the version record for a specified version id. |
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352 | * |
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353 | * @param string $version_id The id of the version to restore. |
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354 | * |
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355 | * @return mixed Array of data saved in version, or false if none. |
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356 | */ |
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357 | function getVerson($version_id) |
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358 | { |
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359 | $this->initDB(); |
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360 | |
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361 | // Get version data. |
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362 | $qid = DB::query(" |
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363 | SELECT * FROM " . $this->getParam('db_table') . " |
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364 | WHERE version_id = '" . DB::escapeString($version_id) . "' |
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365 | "); |
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366 | return mysql_fetch_assoc($qid); |
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367 | } |
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368 | |
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369 | /** |
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370 | * Get the data stored for a specified version id. |
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371 | * |
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372 | * @param string $version_id The id of the version to restore. |
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373 | * |
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374 | * @return mixed Array of data saved in version, or false if none. |
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375 | */ |
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376 | function getData($version_id) |
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377 | { |
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378 | $this->initDB(); |
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379 | |
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380 | // Get version data. |
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381 | $qid = DB::query(" |
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382 | SELECT * FROM " . $this->getParam('db_table') . " |
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383 | WHERE version_id = '" . DB::escapeString($version_id) . "' |
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384 | "); |
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385 | $record = mysql_fetch_assoc($qid); |
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386 | if (isset($record['version_data'])) { |
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387 | return unserialize(gzuncompress($record['version_data'])); |
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388 | } else { |
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389 | return false; |
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390 | } |
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391 | } |
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392 | |
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393 | /** |
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394 | * Get the current record data from the original table. |
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395 | * |
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396 | * @param string $version_id The id of the version to restore. |
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397 | * |
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398 | * @return mixed Array of data saved in version, or false if none. |
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399 | */ |
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400 | function getCurrent($record_table, $record_key, $record_val) |
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401 | { |
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402 | $this->initDB(); |
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403 | |
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404 | $qid = DB::query(" |
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405 | SELECT * FROM " . DB::escapeString($record_table) . " |
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406 | WHERE " . DB::escapeString($record_key) . " = '" . DB::escapeString($record_val) . "' |
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407 | "); |
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408 | if ($record = mysql_fetch_assoc($qid)) { |
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409 | return $record; |
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410 | } else { |
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411 | return false; |
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412 | } |
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413 | } |
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414 | |
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415 | |
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416 | } // End of class. |
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417 | ?> |
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