public function GeofieldProximitySourceBase::getProximity in Geofield 8

Get the calculated proximity.

Parameters

float $lat: The current point latitude.

float $lon: The current point longitude.

Return value

float The calculated proximity.

Throws

\Drupal\geofield\Exception\InvalidPointException; If the proximity cannot be created, due to incorrect point coordinates definition.

\Drupal\geofield\Exception\ProximityUnavailableException; If any other case the proximity value cannot be created correctly.

Overrides GeofieldProximitySourceInterface::getProximity

File

src/Plugin/GeofieldProximitySourceBase.php, line 128

Class

GeofieldProximitySourceBase

Base class for Geofield Proximity Source plugins.

Namespace

Drupal\geofield\Plugin

Code

public function getProximity($lat, $lon) {
  if (!$this
    ->isValidLocation($lat, $lon)) {
    throw new InvalidPointException($this
      ->t('@proximity_handler reports Invalid Point coordinates', [
      '@proximity_handler' => get_class($this),
    ]));
  }

  // Fetch the value of the units that have been set for this class. The
  // constants are defined in the module file.
  $radius = constant($this->units);
  $origin = $this
    ->getOrigin();
  if (!isset($origin['lat']) || !isset($origin['lon']) || $this
    ->isEmptyLocation($origin['lat'], $origin['lon'])) {
    return NULL;
  }

  // Convert degrees to radians.
  $origin_latitude = deg2rad($origin['lat']);
  $origin_longitude = deg2rad($origin['lon']);
  $destination_latitude = deg2rad($lat);
  $destination_longitude = deg2rad($lon);

  // Calculate proximity.
  $proximity = $radius * acos(cos($origin_latitude) * cos($destination_latitude) * cos($destination_longitude - $origin_longitude) + sin($origin_latitude) * sin($destination_latitude));
  if (!is_numeric($proximity)) {
    throw new ProximityUnavailableException($this
      ->t('@proximity_handler not able to calculate valid Proximity value', [
      '@proximity_handler' => get_class($this),
    ]));
  }
  return $proximity;
}