| Matthias Andreas Benkard | 9dabdab | 2024-03-06 13:12:09 +0100 | [diff] [blame] | 1 | <?php |
| 2 | |
| 3 | /* |
| 4 | * Helper functions for building a DataTables server-side processing SQL query |
| 5 | * |
| 6 | * The static functions in this class are just helper functions to help build |
| 7 | * the SQL used in the DataTables demo server-side processing scripts. These |
| 8 | * functions obviously do not represent all that can be done with server-side |
| 9 | * processing, they are intentionally simple to show how it works. More complex |
| 10 | * server-side processing operations will likely require a custom script. |
| 11 | * |
| 12 | * See https://datatables.net/usage/server-side for full details on the server- |
| 13 | * side processing requirements of DataTables. |
| 14 | * |
| 15 | * @license MIT - https://datatables.net/license_mit |
| 16 | */ |
| 17 | |
| 18 | class SSP { |
| 19 | /** |
| 20 | * Create the data output array for the DataTables rows |
| 21 | * |
| 22 | * @param array $columns Column information array |
| 23 | * @param array $data Data from the SQL get |
| 24 | * @return array Formatted data in a row based format |
| 25 | */ |
| 26 | static function data_output ( $columns, $data ) |
| 27 | { |
| 28 | $out = array(); |
| 29 | |
| 30 | for ( $i=0, $ien=count($data) ; $i<$ien ; $i++ ) { |
| 31 | $row = array(); |
| 32 | |
| 33 | for ( $j=0, $jen=count($columns) ; $j<$jen ; $j++ ) { |
| 34 | $column = $columns[$j]; |
| 35 | |
| 36 | // Is there a formatter? |
| 37 | if ( isset( $column['formatter'] ) ) { |
| 38 | if(empty($column['db'])){ |
| 39 | $row[ $column['dt'] ] = $column['formatter']( $data[$i] ); |
| 40 | } |
| 41 | else{ |
| 42 | $row[ $column['dt'] ] = $column['formatter']( $data[$i][ $column['db'] ], $data[$i] ); |
| 43 | } |
| 44 | } |
| 45 | else { |
| 46 | if(!empty($column['db']) && (!isset($column['dummy']) || $column['dummy'] !== true)){ |
| 47 | $row[ $column['dt'] ] = $data[$i][ $columns[$j]['db'] ]; |
| 48 | } |
| 49 | else{ |
| 50 | $row[ $column['dt'] ] = ""; |
| 51 | } |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | $out[] = $row; |
| 56 | } |
| 57 | |
| 58 | return $out; |
| 59 | } |
| 60 | |
| 61 | |
| 62 | /** |
| 63 | * Database connection |
| 64 | * |
| 65 | * Obtain an PHP PDO connection from a connection details array |
| 66 | * |
| 67 | * @param array $conn SQL connection details. The array should have |
| 68 | * the following properties |
| 69 | * * host - host name |
| 70 | * * db - database name |
| 71 | * * user - user name |
| 72 | * * pass - user password |
| 73 | * * Optional: `'charset' => 'utf8'` - you might need this depending on your PHP / MySQL config |
| 74 | * @return resource PDO connection |
| 75 | */ |
| 76 | static function db ( $conn ) |
| 77 | { |
| 78 | if ( is_array( $conn ) ) { |
| 79 | return self::sql_connect( $conn ); |
| 80 | } |
| 81 | |
| 82 | return $conn; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | /** |
| 87 | * Paging |
| 88 | * |
| 89 | * Construct the LIMIT clause for server-side processing SQL query |
| 90 | * |
| 91 | * @param array $request Data sent to server by DataTables |
| 92 | * @param array $columns Column information array |
| 93 | * @return string SQL limit clause |
| 94 | */ |
| 95 | static function limit ( $request, $columns ) |
| 96 | { |
| 97 | $limit = ''; |
| 98 | |
| 99 | if ( isset($request['start']) && $request['length'] != -1 ) { |
| 100 | $limit = "LIMIT ".intval($request['start']).", ".intval($request['length']); |
| 101 | } |
| 102 | |
| 103 | return $limit; |
| 104 | } |
| 105 | |
| 106 | |
| 107 | /** |
| 108 | * Ordering |
| 109 | * |
| 110 | * Construct the ORDER BY clause for server-side processing SQL query |
| 111 | * |
| 112 | * @param array $request Data sent to server by DataTables |
| 113 | * @param array $columns Column information array |
| 114 | * @return string SQL order by clause |
| 115 | */ |
| 116 | static function order ( $tableAS, $request, $columns ) |
| 117 | { |
| 118 | $select = ''; |
| 119 | $order = ''; |
| 120 | |
| 121 | if ( isset($request['order']) && count($request['order']) ) { |
| 122 | $selects = []; |
| 123 | $orderBy = []; |
| 124 | $dtColumns = self::pluck( $columns, 'dt' ); |
| 125 | |
| 126 | for ( $i=0, $ien=count($request['order']) ; $i<$ien ; $i++ ) { |
| 127 | // Convert the column index into the column data property |
| 128 | $columnIdx = intval($request['order'][$i]['column']); |
| 129 | $requestColumn = $request['columns'][$columnIdx]; |
| 130 | |
| 131 | $columnIdx = array_search( $columnIdx, $dtColumns ); |
| 132 | $column = $columns[ $columnIdx ]; |
| 133 | |
| 134 | if ( $requestColumn['orderable'] == 'true' ) { |
| 135 | $dir = $request['order'][$i]['dir'] === 'asc' ? |
| 136 | 'ASC' : |
| 137 | 'DESC'; |
| 138 | |
| 139 | if(isset($column['order_subquery'])) { |
| 140 | $selects[] = '('.$column['order_subquery'].') AS `'.$column['db'].'_count`'; |
| 141 | $orderBy[] = '`'.$column['db'].'_count` '.$dir; |
| 142 | } else { |
| 143 | $orderBy[] = '`'.$tableAS.'`.`'.$column['db'].'` '.$dir; |
| 144 | } |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | if ( count( $selects ) ) { |
| 149 | $select = ', '.implode(', ', $selects); |
| 150 | } |
| 151 | |
| 152 | if ( count( $orderBy ) ) { |
| 153 | $order = 'ORDER BY '.implode(', ', $orderBy); |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | return [$select, $order]; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | /** |
| 162 | * Searching / Filtering |
| 163 | * |
| 164 | * Construct the WHERE clause for server-side processing SQL query. |
| 165 | * |
| 166 | * NOTE this does not match the built-in DataTables filtering which does it |
| 167 | * word by word on any field. It's possible to do here performance on large |
| 168 | * databases would be very poor |
| 169 | * |
| 170 | * @param array $request Data sent to server by DataTables |
| 171 | * @param array $columns Column information array |
| 172 | * @param array $bindings Array of values for PDO bindings, used in the |
| 173 | * sql_exec() function |
| 174 | * @return string SQL where clause |
| 175 | */ |
| 176 | static function filter ( $tablesAS, $request, $columns, &$bindings ) |
| 177 | { |
| 178 | $globalSearch = array(); |
| 179 | $columnSearch = array(); |
| 180 | $joins = array(); |
| 181 | $dtColumns = self::pluck( $columns, 'dt' ); |
| 182 | |
| 183 | if ( isset($request['search']) && $request['search']['value'] != '' ) { |
| 184 | $str = $request['search']['value']; |
| 185 | |
| 186 | for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) { |
| 187 | $requestColumn = $request['columns'][$i]; |
| 188 | $columnIdx = array_search( $i, $dtColumns ); |
| 189 | $column = $columns[ $columnIdx ]; |
| 190 | |
| 191 | if ( $requestColumn['searchable'] == 'true' ) { |
| 192 | if(!empty($column['db'])){ |
| 193 | $binding = self::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR ); |
| 194 | |
| 195 | if(isset($column['search']['join'])) { |
| 196 | $joins[] = $column['search']['join']; |
| 197 | $globalSearch[] = $column['search']['where_column'].' LIKE '.$binding; |
| 198 | } else { |
| 199 | $globalSearch[] = "`".$tablesAS."`.`".$column['db']."` LIKE ".$binding; |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | // Individual column filtering |
| 207 | if ( isset( $request['columns'] ) ) { |
| 208 | for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) { |
| 209 | $requestColumn = $request['columns'][$i]; |
| 210 | $columnIdx = array_search( $requestColumn['data'], $dtColumns ); |
| 211 | $column = $columns[ $columnIdx ]; |
| 212 | |
| 213 | $str = $requestColumn['search']['value']; |
| 214 | |
| 215 | if ( $requestColumn['searchable'] == 'true' && |
| 216 | $str != '' ) { |
| 217 | if(!empty($column['db'])){ |
| 218 | $binding = self::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR ); |
| 219 | $columnSearch[] = "`".$tablesAS."`.`".$column['db']."` LIKE ".$binding; |
| 220 | } |
| 221 | } |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | // Combine the filters into a single string |
| 226 | $where = ''; |
| 227 | |
| 228 | if ( count( $globalSearch ) ) { |
| 229 | $where = '('.implode(' OR ', $globalSearch).')'; |
| 230 | } |
| 231 | |
| 232 | if ( count( $columnSearch ) ) { |
| 233 | $where = $where === '' ? |
| 234 | implode(' AND ', $columnSearch) : |
| 235 | $where .' AND '. implode(' AND ', $columnSearch); |
| 236 | } |
| 237 | |
| 238 | $join = ''; |
| 239 | if( count($joins) ) { |
| 240 | $join = implode(' ', $joins); |
| 241 | } |
| 242 | |
| 243 | if ( $where !== '' ) { |
| 244 | $where = 'WHERE '.$where; |
| 245 | } |
| 246 | |
| 247 | return [$join, $where]; |
| 248 | } |
| 249 | |
| 250 | |
| 251 | /** |
| 252 | * Perform the SQL queries needed for an server-side processing requested, |
| 253 | * utilising the helper functions of this class, limit(), order() and |
| 254 | * filter() among others. The returned array is ready to be encoded as JSON |
| 255 | * in response to an SSP request, or can be modified if needed before |
| 256 | * sending back to the client. |
| 257 | * |
| 258 | * @param array $request Data sent to server by DataTables |
| 259 | * @param array|PDO $conn PDO connection resource or connection parameters array |
| 260 | * @param string $table SQL table to query |
| 261 | * @param string $primaryKey Primary key of the table |
| 262 | * @param array $columns Column information array |
| 263 | * @return array Server-side processing response array |
| 264 | */ |
| 265 | static function simple ( $request, $conn, $table, $primaryKey, $columns ) |
| 266 | { |
| 267 | $bindings = array(); |
| 268 | $db = self::db( $conn ); |
| 269 | |
| 270 | // Allow for a JSON string to be passed in |
| 271 | if (isset($request['json'])) { |
| 272 | $request = json_decode($request['json'], true); |
| 273 | } |
| 274 | |
| 275 | // table AS |
| 276 | $tablesAS = null; |
| 277 | if(is_array($table)) { |
| 278 | $tablesAS = $table[1]; |
| 279 | $table = $table[0]; |
| 280 | } |
| 281 | |
| 282 | // Build the SQL query string from the request |
| 283 | list($select, $order) = self::order( $tablesAS, $request, $columns ); |
| 284 | $limit = self::limit( $request, $columns ); |
| 285 | list($join, $where) = self::filter( $tablesAS, $request, $columns, $bindings ); |
| 286 | |
| 287 | // Main query to actually get the data |
| 288 | $data = self::sql_exec( $db, $bindings, |
| 289 | "SELECT `$tablesAS`.`".implode("`, `$tablesAS`.`", self::pluck($columns, 'db'))."` |
| 290 | $select |
| 291 | FROM `$table` AS `$tablesAS` |
| 292 | $join |
| 293 | $where |
| 294 | GROUP BY `{$tablesAS}`.`{$primaryKey}` |
| 295 | $order |
| 296 | $limit" |
| 297 | ); |
| 298 | |
| 299 | // Data set length after filtering |
| 300 | $resFilterLength = self::sql_exec( $db, $bindings, |
| 301 | "SELECT COUNT(DISTINCT `{$tablesAS}`.`{$primaryKey}`) |
| 302 | FROM `$table` AS `$tablesAS` |
| 303 | $join |
| 304 | $where" |
| 305 | ); |
| 306 | $recordsFiltered = $resFilterLength[0][0]; |
| 307 | |
| 308 | // Total data set length |
| 309 | $resTotalLength = self::sql_exec( $db, |
| 310 | "SELECT COUNT(`{$tablesAS}`.`{$primaryKey}`) |
| 311 | FROM `$table` AS `$tablesAS`" |
| 312 | ); |
| 313 | $recordsTotal = $resTotalLength[0][0]; |
| 314 | |
| 315 | /* |
| 316 | * Output |
| 317 | */ |
| 318 | return array( |
| 319 | "draw" => isset ( $request['draw'] ) ? |
| 320 | intval( $request['draw'] ) : |
| 321 | 0, |
| 322 | "recordsTotal" => intval( $recordsTotal ), |
| 323 | "recordsFiltered" => intval( $recordsFiltered ), |
| 324 | "data" => self::data_output( $columns, $data ) |
| 325 | ); |
| 326 | } |
| 327 | |
| 328 | |
| 329 | /** |
| 330 | * The difference between this method and the `simple` one, is that you can |
| 331 | * apply additional `where` conditions to the SQL queries. These can be in |
| 332 | * one of two forms: |
| 333 | * |
| 334 | * * 'Result condition' - This is applied to the result set, but not the |
| 335 | * overall paging information query - i.e. it will not effect the number |
| 336 | * of records that a user sees they can have access to. This should be |
| 337 | * used when you want apply a filtering condition that the user has sent. |
| 338 | * * 'All condition' - This is applied to all queries that are made and |
| 339 | * reduces the number of records that the user can access. This should be |
| 340 | * used in conditions where you don't want the user to ever have access to |
| 341 | * particular records (for example, restricting by a login id). |
| 342 | * |
| 343 | * In both cases the extra condition can be added as a simple string, or if |
| 344 | * you are using external values, as an assoc. array with `condition` and |
| 345 | * `bindings` parameters. The `condition` is a string with the SQL WHERE |
| 346 | * condition and `bindings` is an assoc. array of the binding names and |
| 347 | * values. |
| 348 | * |
| 349 | * @param array $request Data sent to server by DataTables |
| 350 | * @param array|PDO $conn PDO connection resource or connection parameters array |
| 351 | * @param string|array $table SQL table to query, if array second key is AS |
| 352 | * @param string $primaryKey Primary key of the table |
| 353 | * @param array $columns Column information array |
| 354 | * @param string $join JOIN sql string |
| 355 | * @param string|array $whereResult WHERE condition to apply to the result set |
| 356 | * @return array Server-side processing response array |
| 357 | */ |
| 358 | static function complex ( |
| 359 | $request, |
| 360 | $conn, |
| 361 | $table, |
| 362 | $primaryKey, |
| 363 | $columns, |
| 364 | $join=null, |
| 365 | $whereResult=null |
| 366 | ) { |
| 367 | $bindings = array(); |
| 368 | $db = self::db( $conn ); |
| 369 | |
| 370 | // table AS |
| 371 | $tablesAS = null; |
| 372 | if(is_array($table)) { |
| 373 | $tablesAS = $table[1]; |
| 374 | $table = $table[0]; |
| 375 | } |
| 376 | |
| 377 | // Build the SQL query string from the request |
| 378 | list($select, $order) = self::order( $tablesAS, $request, $columns ); |
| 379 | $limit = self::limit( $request, $columns ); |
| 380 | list($join_filter, $where) = self::filter( $tablesAS, $request, $columns, $bindings ); |
| 381 | |
| 382 | // whereResult can be a simple string, or an assoc. array with a |
| 383 | // condition and bindings |
| 384 | if ( $whereResult ) { |
| 385 | $str = $whereResult; |
| 386 | |
| 387 | if ( is_array($whereResult) ) { |
| 388 | $str = $whereResult['condition']; |
| 389 | |
| 390 | if ( isset($whereResult['bindings']) ) { |
| 391 | self::add_bindings($bindings, $whereResult); |
| 392 | } |
| 393 | } |
| 394 | |
| 395 | $where = $where ? |
| 396 | $where .' AND '.$str : |
| 397 | 'WHERE '.$str; |
| 398 | } |
| 399 | |
| 400 | // Main query to actually get the data |
| 401 | $data = self::sql_exec( $db, $bindings, |
| 402 | "SELECT `$tablesAS`.`".implode("`, `$tablesAS`.`", self::pluck($columns, 'db'))."` |
| 403 | $select |
| 404 | FROM `$table` AS `$tablesAS` |
| 405 | $join |
| 406 | $join_filter |
| 407 | $where |
| 408 | GROUP BY `{$tablesAS}`.`{$primaryKey}` |
| 409 | $order |
| 410 | $limit" |
| 411 | ); |
| 412 | |
| 413 | // Data set length after filtering |
| 414 | $resFilterLength = self::sql_exec( $db, $bindings, |
| 415 | "SELECT COUNT(DISTINCT `{$tablesAS}`.`{$primaryKey}`) |
| 416 | FROM `$table` AS `$tablesAS` |
| 417 | $join |
| 418 | $join_filter |
| 419 | $where" |
| 420 | ); |
| 421 | $recordsFiltered = (isset($resFilterLength[0])) ? $resFilterLength[0][0] : 0; |
| 422 | |
| 423 | // Total data set length |
| 424 | $resTotalLength = self::sql_exec( $db, $bindings, |
| 425 | "SELECT COUNT(`{$tablesAS}`.`{$primaryKey}`) |
| 426 | FROM `$table` AS `$tablesAS` |
| 427 | $join |
| 428 | $join_filter |
| 429 | $where" |
| 430 | ); |
| 431 | $recordsTotal = (isset($resTotalLength[0])) ? $resTotalLength[0][0] : 0; |
| 432 | |
| 433 | /* |
| 434 | * Output |
| 435 | */ |
| 436 | return array( |
| 437 | "draw" => isset ( $request['draw'] ) ? |
| 438 | intval( $request['draw'] ) : |
| 439 | 0, |
| 440 | "recordsTotal" => intval( $recordsTotal ), |
| 441 | "recordsFiltered" => intval( $recordsFiltered ), |
| 442 | "data" => self::data_output( $columns, $data ) |
| 443 | ); |
| 444 | } |
| 445 | |
| 446 | |
| 447 | /** |
| 448 | * Connect to the database |
| 449 | * |
| 450 | * @param array $sql_details SQL server connection details array, with the |
| 451 | * properties: |
| 452 | * * host - host name |
| 453 | * * db - database name |
| 454 | * * user - user name |
| 455 | * * pass - user password |
| 456 | * @return resource Database connection handle |
| 457 | */ |
| 458 | static function sql_connect ( $sql_details ) |
| 459 | { |
| 460 | try { |
| 461 | $db = @new PDO( |
| 462 | "mysql:host={$sql_details['host']};dbname={$sql_details['db']}", |
| 463 | $sql_details['user'], |
| 464 | $sql_details['pass'], |
| 465 | array( PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION ) |
| 466 | ); |
| 467 | } |
| 468 | catch (PDOException $e) { |
| 469 | self::fatal( |
| 470 | "An error occurred while connecting to the database. ". |
| 471 | "The error reported by the server was: ".$e->getMessage() |
| 472 | ); |
| 473 | } |
| 474 | |
| 475 | return $db; |
| 476 | } |
| 477 | |
| 478 | |
| 479 | /** |
| 480 | * Execute an SQL query on the database |
| 481 | * |
| 482 | * @param resource $db Database handler |
| 483 | * @param array $bindings Array of PDO binding values from bind() to be |
| 484 | * used for safely escaping strings. Note that this can be given as the |
| 485 | * SQL query string if no bindings are required. |
| 486 | * @param string $sql SQL query to execute. |
| 487 | * @return array Result from the query (all rows) |
| 488 | */ |
| 489 | static function sql_exec ( $db, $bindings, $sql=null ) |
| 490 | { |
| 491 | // Argument shifting |
| 492 | if ( $sql === null ) { |
| 493 | $sql = $bindings; |
| 494 | } |
| 495 | |
| 496 | $stmt = $db->prepare( $sql ); |
| 497 | |
| 498 | // Bind parameters |
| 499 | if ( is_array( $bindings ) ) { |
| 500 | for ( $i=0, $ien=count($bindings) ; $i<$ien ; $i++ ) { |
| 501 | $binding = $bindings[$i]; |
| 502 | $stmt->bindValue( $binding['key'], $binding['val'], $binding['type'] ); |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | // Execute |
| 507 | try { |
| 508 | $stmt->execute(); |
| 509 | } |
| 510 | catch (PDOException $e) { |
| 511 | self::fatal( "An SQL error occurred: ".$e->getMessage() ); |
| 512 | } |
| 513 | |
| 514 | // Return all |
| 515 | return $stmt->fetchAll( PDO::FETCH_BOTH ); |
| 516 | } |
| 517 | |
| 518 | |
| 519 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
| 520 | * Internal methods |
| 521 | */ |
| 522 | |
| 523 | /** |
| 524 | * Throw a fatal error. |
| 525 | * |
| 526 | * This writes out an error message in a JSON string which DataTables will |
| 527 | * see and show to the user in the browser. |
| 528 | * |
| 529 | * @param string $msg Message to send to the client |
| 530 | */ |
| 531 | static function fatal ( $msg ) |
| 532 | { |
| 533 | echo json_encode( array( |
| 534 | "error" => $msg |
| 535 | ) ); |
| 536 | |
| 537 | exit(0); |
| 538 | } |
| 539 | |
| 540 | /** |
| 541 | * Create a PDO binding key which can be used for escaping variables safely |
| 542 | * when executing a query with sql_exec() |
| 543 | * |
| 544 | * @param array &$a Array of bindings |
| 545 | * @param * $val Value to bind |
| 546 | * @param int $type PDO field type |
| 547 | * @return string Bound key to be used in the SQL where this parameter |
| 548 | * would be used. |
| 549 | */ |
| 550 | static function bind ( &$a, $val, $type ) |
| 551 | { |
| 552 | $key = ':binding_'.count( $a ); |
| 553 | |
| 554 | $a[] = array( |
| 555 | 'key' => $key, |
| 556 | 'val' => $val, |
| 557 | 'type' => $type |
| 558 | ); |
| 559 | |
| 560 | return $key; |
| 561 | } |
| 562 | |
| 563 | static function add_bindings(&$bindings, $vals) |
| 564 | { |
| 565 | foreach($vals['bindings'] as $key => $value) { |
| 566 | $bindings[] = array( |
| 567 | 'key' => $key, |
| 568 | 'val' => $value, |
| 569 | 'type' => PDO::PARAM_STR |
| 570 | ); |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | |
| 575 | /** |
| 576 | * Pull a particular property from each assoc. array in a numeric array, |
| 577 | * returning and array of the property values from each item. |
| 578 | * |
| 579 | * @param array $a Array to get data from |
| 580 | * @param string $prop Property to read |
| 581 | * @return array Array of property values |
| 582 | */ |
| 583 | static function pluck ( $a, $prop ) |
| 584 | { |
| 585 | $out = array(); |
| 586 | |
| 587 | for ( $i=0, $len=count($a) ; $i<$len ; $i++ ) { |
| 588 | if ( empty($a[$i][$prop]) && $a[$i][$prop] !== 0 ) { |
| 589 | continue; |
| 590 | } |
| 591 | if ( $prop == 'db' && isset($a[$i]['dummy']) && $a[$i]['dummy'] === true ) { |
| 592 | continue; |
| 593 | } |
| 594 | |
| 595 | //removing the $out array index confuses the filter method in doing proper binding, |
| 596 | //adding it ensures that the array data are mapped correctly |
| 597 | $out[$i] = $a[$i][$prop]; |
| 598 | } |
| 599 | |
| 600 | return $out; |
| 601 | } |
| 602 | |
| 603 | |
| 604 | /** |
| 605 | * Return a string from an array or a string |
| 606 | * |
| 607 | * @param array|string $a Array to join |
| 608 | * @param string $join Glue for the concatenation |
| 609 | * @return string Joined string |
| 610 | */ |
| 611 | static function _flatten ( $a, $join = ' AND ' ) |
| 612 | { |
| 613 | if ( ! $a ) { |
| 614 | return ''; |
| 615 | } |
| 616 | else if ( $a && is_array($a) ) { |
| 617 | return implode( $join, $a ); |
| 618 | } |
| 619 | return $a; |
| 620 | } |
| 621 | } |
| 622 | |