GPX.class.php in geoPHP 7

File

geoPHP/lib/adapters/GPX.class.php

<?php

/*
 * Copyright (c) Patrick Hayes
 *
 * This code is open-source and licenced under the Modified BSD License.
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * PHP Geometry/GPX encoder/decoder
 */
class GPX extends GeoAdapter {
  private $namespace = FALSE;
  private $nss = '';

  // Name-space string. eg 'georss:'

  /**
   * Read GPX string into geometry objects
   *
   * @param string $gpx A GPX string
   *
   * @return Geometry|GeometryCollection
   */
  public function read($gpx) {
    return $this
      ->geomFromText($gpx);
  }

  /**
   * Serialize geometries into a GPX string.
   *
   * @param Geometry $geometry
   *
   * @return string The GPX string representation of the input geometries
   */
  public function write(Geometry $geometry, $namespace = FALSE) {
    if ($geometry
      ->isEmpty()) {
      return NULL;
    }
    if ($namespace) {
      $this->namespace = $namespace;
      $this->nss = $namespace . ':';
    }
    return '<' . $this->nss . 'gpx creator="geoPHP" version="1.0">' . $this
      ->geometryToGPX($geometry) . '</' . $this->nss . 'gpx>';
  }
  public function geomFromText($text) {

    // Change to lower-case and strip all CDATA
    $text = strtolower($text);
    $text = preg_replace('/<!\\[cdata\\[(.*?)\\]\\]>/s', '', $text);

    // Load into DOMDocument
    $xmlobj = new DOMDocument();
    @$xmlobj
      ->loadXML($text);
    if ($xmlobj === false) {
      throw new Exception("Invalid GPX: " . $text);
    }
    $this->xmlobj = $xmlobj;
    try {
      $geom = $this
        ->geomFromXML();
    } catch (InvalidText $e) {
      throw new Exception("Cannot Read Geometry From GPX: " . $text);
    } catch (Exception $e) {
      throw $e;
    }
    return $geom;
  }
  protected function geomFromXML() {
    $geometries = array();
    $geometries = array_merge($geometries, $this
      ->parseWaypoints());
    $geometries = array_merge($geometries, $this
      ->parseTracks());
    $geometries = array_merge($geometries, $this
      ->parseRoutes());
    if (empty($geometries)) {
      throw new Exception("Invalid / Empty GPX");
    }
    return geoPHP::geometryReduce($geometries);
  }
  protected function childElements($xml, $nodename = '') {
    $children = array();
    foreach ($xml->childNodes as $child) {
      if ($child->nodeName == $nodename) {
        $children[] = $child;
      }
    }
    return $children;
  }
  protected function parseWaypoints() {
    $points = array();
    $wpt_elements = $this->xmlobj
      ->getElementsByTagName('wpt');
    foreach ($wpt_elements as $wpt) {
      $lat = $wpt->attributes
        ->getNamedItem("lat")->nodeValue;
      $lon = $wpt->attributes
        ->getNamedItem("lon")->nodeValue;
      $points[] = new Point($lon, $lat);
    }
    return $points;
  }
  protected function parseTracks() {
    $lines = array();
    $trk_elements = $this->xmlobj
      ->getElementsByTagName('trk');
    foreach ($trk_elements as $trk) {
      $components = array();
      foreach ($this
        ->childElements($trk, 'trkseg') as $trkseg) {
        foreach ($this
          ->childElements($trkseg, 'trkpt') as $trkpt) {
          $lat = $trkpt->attributes
            ->getNamedItem("lat")->nodeValue;
          $lon = $trkpt->attributes
            ->getNamedItem("lon")->nodeValue;
          $components[] = new Point($lon, $lat);
        }
      }
      if ($components) {
        $lines[] = new LineString($components);
      }
    }
    return $lines;
  }
  protected function parseRoutes() {
    $lines = array();
    $rte_elements = $this->xmlobj
      ->getElementsByTagName('rte');
    foreach ($rte_elements as $rte) {
      $components = array();
      foreach ($this
        ->childElements($rte, 'rtept') as $rtept) {
        $lat = $rtept->attributes
          ->getNamedItem("lat")->nodeValue;
        $lon = $rtept->attributes
          ->getNamedItem("lon")->nodeValue;
        $components[] = new Point($lon, $lat);
      }
      $lines[] = new LineString($components);
    }
    return $lines;
  }
  protected function geometryToGPX($geom) {
    $type = strtolower($geom
      ->getGeomType());
    switch ($type) {
      case 'point':
        return $this
          ->pointToGPX($geom);
        break;
      case 'linestring':
        return $this
          ->linestringToGPX($geom);
        break;
      case 'polygon':
      case 'multipoint':
      case 'multilinestring':
      case 'multipolygon':
      case 'geometrycollection':
        return $this
          ->collectionToGPX($geom);
        break;
    }
  }
  private function pointToGPX($geom) {
    return '<' . $this->nss . 'wpt lat="' . $geom
      ->getY() . '" lon="' . $geom
      ->getX() . '" />';
  }
  private function linestringToGPX($geom) {
    $gpx = '<' . $this->nss . 'trk><' . $this->nss . 'trkseg>';
    foreach ($geom
      ->getComponents() as $comp) {
      $gpx .= '<' . $this->nss . 'trkpt lat="' . $comp
        ->getY() . '" lon="' . $comp
        ->getX() . '" />';
    }
    $gpx .= '</' . $this->nss . 'trkseg></' . $this->nss . 'trk>';
    return $gpx;
  }
  public function collectionToGPX($geom) {
    $gpx = '';
    $components = $geom
      ->getComponents();
    foreach ($geom
      ->getComponents() as $comp) {
      $gpx .= $this
        ->geometryToGPX($comp);
    }
    return $gpx;
  }

}

Classes

Name	Description
GPX	PHP Geometry/GPX encoder/decoder