如何从同一个php文件发布和获取数据[PHP]

I've php file and with this I want both set and get data. (Is it possible?).

This is my php file:

require_once 'GetAreaDB.php';

$latitudeFrom = $_POST['latitudeFrom'];
$longitudeFrom = $_POST['longitudeFrom'];
$maxDistance = $_POST['maxDistance'];
// These three values come from my swift app.

$getArea1 = new GetAreaDB();
$locals = $getArea1->getPositionByCoordinate($latitudeFrom,$longitudeFrom,$maxDistance);

$jsonArray = array();

foreach ($locals as $local) {

    $jsonArray1 = array(

        "id" => $local->getID(),
        "json_local" => $local->getJSON()
    );

    array_push($jsonArray,$jsonArray1);
}

echo json_encode($jsonArray);

My idea is to create a php file that receives post parameters and then, on the base of these, it get other data. How can I solve?