/**
* @param $from - string|array
* string: GeoJson representation of POINT
* array: location in the form [ <lng>, <lat> ] (two floats)
* @param $attribute - attribute name of POINT
* @param $radius number - search radius in kilometers
* @return $this - query that returns models that are near to $from
*
* Example usages:
* $here = [4.9, 52.3]; // longitude and latitude of my place
* $nearestModel = <model>::find()->nearest($here, <attributeName>, 100)->one(); // search radius is 100 km
* $fiveNearestModels = <model>::find()->nearest($here, <attributeName>, 100)->limit(5)->all();
* $dataProvider = new ActiveDataProvider([ 'query' => <model>::find()->nearest($here, <attributeName>, 100) ]);
*
*
* @link http://www.plumislandmedia.net/mysql/haversine-mysql-nearest-loc/
* @link https://en.wikipedia.org/wiki/Haversine_formula
*/
public function nearest($from, $attribute, $radius = 100)
{
$lenPerDegree = 111.045;
// km per degree latitude; for miles, use 69.0
if (is_string($from)) {
$feat = SpatialHelper::jsonToGeom($from);
if ($feat && $feat['type'] == 'Point') {
$from = $feat['coordinates'];
}
}
if (!is_array($from)) {
return $this;
}
$lng = $from[0];
$lat = $from[1];
$dLat = $radius / $lenPerDegree;
$dLng = $dLat / cos(deg2rad($lat));
/** @var \yii\db\ActiveRecord $modelCls */
$modelCls = $this->modelClass;
$subQuery = $this->create($this)->from($modelCls::tableName())->select(['*', '_lng' => "X({$attribute})", '_lat' => "Y({$attribute})"])->having(['between', '_lng', $lng - $dLng, $lng + $dLng])->andHaving(['between', '_lat', $lat - $dLat, $lat + $dLat]);
$this->from([$subQuery])->select(['*', '_d' => "{$lenPerDegree}*DEGREES(ACOS(COS(RADIANS(:lt))*COS(RADIANS(_lat))*COS(RADIANS(:lg)-RADIANS(_lng))+SIN(RADIANS(:lt))*SIN(RADIANS(_lat))))"])->params([':lg' => $lng, ':lt' => $lat])->having(['<', '_d', $radius])->orderBy(['_d' => SORT_ASC]);
$this->where = null;
$this->limit = null;
$this->offset = null;
$this->distinct = null;
$this->groupBy = null;
$this->join = null;
$this->union = null;
return $this;
}
public function afterFind()
{
parent::afterFind();
$scheme = static::getTableSchema();
foreach ($scheme->columns as $column) {
if (static::isSpatial($column)) {
$field = $column->name;
$attr = $this->getAttribute($field);
// get WKT
if ($attr) {
if (YII_DEBUG && preg_match('/[\\x80-\\xff]+/', $attr)) {
/* If you get an exception here, it probably means you have overridden find()
and did not return sjaakp\spatial\ActiveQuery. */
throw new InvalidCallException('Spatial attribute not converted.');
}
$geom = SpatialHelper::wktToGeom($attr);
// Transform geometry FeatureCollection...
if ($geom['type'] == 'GeometryCollection') {
$feats = [];
foreach ($geom['geometries'] as $g) {
$feats[] = ['type' => 'Feature', 'geometry' => $g, 'properties' => $this->featureProperties($field, $g)];
}
$feature = ['type' => 'FeatureCollection', 'features' => $feats];
} else {
// ... or to Feature
$feature = SpatialHelper::geomToFeature($geom, $this->featureProperties($field, $geom));
}
$this->setAttribute($field, Json::encode($feature));
}
}
}
}
