/**
* Convert the geometry to geohash.
* @return string the geohash or null when the $geometry is not a Point
* @param Point $geometry
* @see GeoAdapter::write()
*/
public function write(Geometry $geometry, $precision = NULL)
{
if ($geometry->isEmpty()) {
return '';
}
if ($geometry->geometryType() === 'Point') {
return $this->encodePoint($geometry, $precision);
} else {
// The geohash is the hash grid ID that fits the envelope
$envelope = $geometry->envelope();
$geohashes = array();
$geohash = '';
foreach ($envelope->getPoints() as $point) {
$geohashes[] = $this->encodePoint($point, 1.0E-7);
}
$i = 0;
while ($i < strlen($geohashes[0])) {
$char = $geohashes[0][$i];
foreach ($geohashes as $hash) {
if ($hash[$i] != $char) {
return $geohash;
}
}
$geohash .= $char;
$i++;
}
return $geohash;
}
}
/**
* Extract geometry to a WKT string
*
* @param Geometry $geometry A Geometry object
*
* @return string
*/
public function extractData($geometry)
{
$parts = array();
switch ($geometry->geometryType()) {
case 'Point':
return $geometry->getX() . ' ' . $geometry->getY();
case 'LineString':
foreach ($geometry->getComponents() as $component) {
$parts[] = $this->extractData($component);
}
return implode(', ', $parts);
case 'Polygon':
case 'MultiPoint':
case 'MultiLineString':
case 'MultiPolygon':
foreach ($geometry->getComponents() as $component) {
$parts[] = '(' . $this->extractData($component) . ')';
}
return implode(', ', $parts);
case 'GeometryCollection':
foreach ($geometry->getComponents() as $component) {
$parts[] = strtoupper($component->geometryType()) . ' (' . $this->extractData($component) . ')';
}
return implode(', ', $parts);
}
}
