Complex classes like ShapeFile often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use ShapeFile, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 29 | class ShapeFile { |
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| 30 | const MAGIC = 0x270a; |
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| 31 | |||
| 32 | public $FileName; |
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| 33 | |||
| 34 | private $SHPFile = null; |
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| 35 | private $SHXFile = null; |
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| 36 | private $DBFFile = null; |
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| 37 | |||
| 38 | private $DBFHeader; |
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| 39 | |||
| 40 | public $lastError = ''; |
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| 41 | |||
| 42 | public $boundingBox = array('xmin' => 0.0, 'ymin' => 0.0, 'xmax' => 0.0, 'ymax' => 0.0); |
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| 43 | private $fileLength = 0; |
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| 44 | public $shapeType = 0; |
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| 45 | |||
| 46 | public $records; |
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| 47 | |||
| 48 | /** |
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| 49 | * Checks whether dbase manipuations are supported. |
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| 50 | * |
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| 51 | * @return bool |
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| 52 | */ |
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| 53 | 21 | public static function supports_dbase() |
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| 57 | |||
| 58 | /** |
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| 59 | * @param integer $shapeType |
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| 60 | */ |
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| 61 | 24 | public function __construct($shapeType, $boundingBox = array('xmin' => 0.0, 'ymin' => 0.0, 'xmax' => 0.0, 'ymax' => 0.0), $FileName = null) { |
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| 67 | |||
| 68 | /** |
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| 69 | * @param string $FileName |
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| 70 | */ |
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| 71 | 22 | public function loadFromFile($FileName) { |
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| 98 | |||
| 99 | /** |
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| 100 | * @param string|null $FileName Name of file to open |
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| 101 | */ |
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| 102 | 13 | public function saveToFile($FileName = null) { |
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| 117 | |||
| 118 | /** |
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| 119 | * Generates filename with given extension |
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| 120 | * |
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| 121 | * @param string $extension Extension to use (including dot) |
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| 122 | * |
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| 123 | * @return string |
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| 124 | */ |
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| 125 | 23 | private function _getFilename($extension) |
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| 129 | |||
| 130 | /** |
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| 131 | * Updates bounding box based on SHPData |
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| 132 | * |
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| 133 | * @param string $type Type of box |
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| 134 | * @param array $data ShapeRecord SHPData |
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| 135 | * |
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| 136 | * @return void |
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| 137 | */ |
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| 138 | 12 | private function updateBBox($type, $data) |
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| 150 | |||
| 151 | /** |
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| 152 | * @param ShapeRecord $record |
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| 153 | */ |
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| 154 | 12 | public function addRecord($record) { |
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| 176 | |||
| 177 | /** |
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| 178 | * @param integer $index |
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| 179 | */ |
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| 180 | public function deleteRecord($index) { |
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| 191 | |||
| 192 | /** |
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| 193 | * Returns array defining fields in DBF file |
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| 194 | * |
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| 195 | * @return array See setDBFHeader for more information. |
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| 196 | */ |
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| 197 | public function getDBFHeader() { |
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| 200 | |||
| 201 | /** |
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| 202 | * Changes array defining fields in DBF file, used in dbase_create call |
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| 203 | * |
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| 204 | * @param array $header An array of arrays, each array describing the |
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| 205 | * format of one field of the database. Each |
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| 206 | * field consists of a name, a character indicating |
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| 207 | * the field type, and optionally, a length, |
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| 208 | * a precision and a nullable flag. |
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| 209 | */ |
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| 210 | 12 | public function setDBFHeader($header) { |
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| 218 | |||
| 219 | /** |
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| 220 | * Lookups value in the DBF file and returs index |
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| 221 | * |
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| 222 | * @param string $field Field to match |
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| 223 | * @param mixed $value Value to match |
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| 224 | * |
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| 225 | * @return integer |
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| 226 | */ |
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| 227 | 1 | public function getIndexFromDBFData($field, $value) { |
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| 238 | |||
| 239 | private function _loadDBFHeader() { |
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| 273 | |||
| 274 | private function _deleteRecordFromDBF($index) { |
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| 279 | |||
| 280 | 20 | private function _loadHeaders() { |
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| 281 | 20 | if (Util::loadData('N', $this->readSHP(4)) != ShapeFile::MAGIC) { |
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| 282 | 1 | $this->setError('Not a SHP file (file code mismatch)'); |
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| 283 | 1 | return false; |
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| 284 | } |
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| 285 | |||
| 286 | /* Skip 20 unused bytes */ |
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| 287 | 19 | $this->readSHP(20); |
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| 288 | |||
| 289 | 19 | $this->fileLength = Util::loadData('N', $this->readSHP(4)); |
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| 290 | |||
| 291 | /* We currently ignore version */ |
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| 292 | 19 | $this->readSHP(4); |
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| 293 | |||
| 294 | 19 | $this->shapeType = Util::loadData('V', $this->readSHP(4)); |
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| 295 | |||
| 296 | 19 | $this->boundingBox = array(); |
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| 297 | 19 | $this->boundingBox['xmin'] = Util::loadData('d', $this->readSHP(8)); |
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| 298 | 19 | $this->boundingBox['ymin'] = Util::loadData('d', $this->readSHP(8)); |
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| 299 | 19 | $this->boundingBox['xmax'] = Util::loadData('d', $this->readSHP(8)); |
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| 300 | 19 | $this->boundingBox['ymax'] = Util::loadData('d', $this->readSHP(8)); |
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| 301 | 19 | $this->boundingBox['zmin'] = Util::loadData('d', $this->readSHP(8)); |
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| 302 | 19 | $this->boundingBox['zmax'] = Util::loadData('d', $this->readSHP(8)); |
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| 303 | 19 | $this->boundingBox['mmin'] = Util::loadData('d', $this->readSHP(8)); |
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| 304 | 19 | $this->boundingBox['mmax'] = Util::loadData('d', $this->readSHP(8)); |
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| 305 | |||
| 306 | 19 | if (ShapeFile::supports_dbase()) { |
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| 307 | $this->DBFHeader = $this->_loadDBFHeader(); |
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| 308 | } |
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| 309 | 19 | return true; |
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| 310 | } |
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| 311 | |||
| 312 | 13 | private function _saveBBoxRecord($file, $type) { |
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| 317 | |||
| 318 | 13 | private function _saveBBox($file) { |
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| 328 | |||
| 329 | 13 | private function _saveHeaders() { |
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| 330 | 13 | fwrite($this->SHPFile, pack('NNNNNN', ShapeFile::MAGIC, 0, 0, 0, 0, 0)); |
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| 331 | 13 | fwrite($this->SHPFile, pack('N', $this->fileLength)); |
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| 332 | 13 | fwrite($this->SHPFile, pack('V', 1000)); |
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| 333 | 13 | fwrite($this->SHPFile, pack('V', $this->shapeType)); |
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| 334 | 13 | $this->_saveBBox($this->SHPFile); |
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| 335 | |||
| 336 | 13 | fwrite($this->SHXFile, pack('NNNNNN', ShapeFile::MAGIC, 0, 0, 0, 0, 0)); |
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| 337 | 13 | fwrite($this->SHXFile, pack('N', 50 + 4 * count($this->records))); |
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| 338 | 13 | fwrite($this->SHXFile, pack('V', 1000)); |
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| 339 | 13 | fwrite($this->SHXFile, pack('V', $this->shapeType)); |
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| 340 | 13 | $this->_saveBBox($this->SHXFile); |
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| 341 | 13 | } |
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| 342 | |||
| 343 | 19 | private function _loadRecords() { |
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| 360 | |||
| 361 | 13 | private function _saveRecords() { |
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| 375 | |||
| 376 | 23 | private function _openFile($toWrite, $extension, $name) { |
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| 386 | |||
| 387 | 23 | private function _openSHPFile($toWrite = false) { |
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| 394 | |||
| 395 | 21 | private function _closeSHPFile() { |
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| 401 | |||
| 402 | 13 | private function _openSHXFile($toWrite = false) { |
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| 409 | |||
| 410 | 13 | private function _closeSHXFile() { |
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| 416 | |||
| 417 | /** |
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| 418 | * Creates DBF file |
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| 419 | * |
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| 420 | * @return bool |
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| 421 | */ |
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| 422 | 13 | private function _createDBFFile() |
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| 444 | |||
| 445 | /** |
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| 446 | * Loads DBF file if supported |
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| 447 | * |
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| 448 | * @return bool |
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| 449 | */ |
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| 450 | 20 | private function _openDBFFile() { |
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| 451 | 20 | if (!ShapeFile::supports_dbase()) { |
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| 452 | 20 | $this->DBFFile = null; |
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| 453 | 20 | return true; |
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| 454 | } |
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| 455 | $dbf_name = $this->_getFilename('.dbf'); |
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| 456 | if (is_readable($dbf_name)) { |
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| 457 | $this->DBFFile = @dbase_open($dbf_name, 0); |
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| 458 | if (!$this->DBFFile) { |
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| 459 | $this->setError(sprintf('It wasn\'t possible to open the DBase file "%s"', $dbf_name)); |
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| 460 | return false; |
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| 461 | } |
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| 462 | } else { |
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| 463 | $this->setError(sprintf('It wasn\'t possible to find the DBase file "%s"', $dbf_name)); |
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| 464 | return false; |
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| 465 | } |
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| 466 | return true; |
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| 467 | } |
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| 468 | |||
| 469 | 21 | private function _closeDBFFile() { |
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| 475 | |||
| 476 | /** |
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| 477 | * Sets error message |
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| 478 | * |
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| 479 | * @param string $error |
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| 480 | * |
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| 481 | * @return void |
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| 482 | */ |
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| 483 | 3 | public function setError($error) { |
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| 486 | |||
| 487 | /** |
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| 488 | * Reads given number of bytes from SHP file |
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| 489 | * |
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| 490 | * @param integer $bytes |
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| 491 | * |
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| 492 | * @return string |
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| 493 | */ |
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| 494 | 20 | public function readSHP($bytes) |
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| 498 | |||
| 499 | /** |
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| 500 | * Checks whether file is at EOF |
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| 501 | * |
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| 502 | * @return bool |
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| 503 | */ |
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| 504 | 19 | public function eofSHP() |
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| 508 | |||
| 509 | /** |
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| 510 | * Returns shape name |
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| 511 | * |
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| 512 | * @return string |
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| 513 | */ |
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| 514 | 1 | public function getShapeName() |
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| 518 | |||
| 519 | /** |
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| 520 | * Check whether file contains measure data. |
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| 521 | * |
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| 522 | * For some reason this is distinguished by zero bouding box in the |
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| 523 | * specification. |
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| 524 | * |
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| 525 | * @return bool |
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| 526 | */ |
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| 527 | 8 | public function hasMeasure() |
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| 531 | } |
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| 532 | |||
| 533 |