$lat1 = $row[1]; //Set $lat1 to the latitude of the current user
$lng1 = $row[2]; //Set $lng1 to the longitude of the current user
}
}
if ($lat1 == 0 && $lng1 == 0) { //Check if the user get found in the database
print(json_encode("ERROR No user found in the database")); //Return a json string, so the dart script can interpret the error
exit(1); //Exit the actual script
}
$results = mysqli_query($connect, $query); //Execute again the SQL command to restart the fetch_row()
while ($row = $results->fetch_row()) { //For all the row in the database
if (strcmp($row[0], $id) != 0) { //If the row is not the row of the current user
$lat2 = $row[1]; //Set $lat2 to the latitude of the user who is in the actual row
$lng2 = $row[2]; //Set $lng2 to the latitude of the user who is in the actual row
$userID = $row[0]; //Set $userID to the username of the user who is in the actual row
$idMusic = $row[3]; //Set $idMusic to the id of the actual song of the user who is in the actual row
$dist = meters($lat1, $lng1, $lat2, $lng2); //With the function meters, calcul of the distance between the current user and the user who is in the actual row
if ($dist <= 100) { //If the user in the actual row is less than 100 meters away of the current user
$listUser[] = ['user' => $userID, 'music' => $idMusic]; //Add the username and the ID of the song that user who is in the actual row is listening
}
}
}
}
print(json_encode($listUser)); //Return a json string of the list listUser
}else{ //If the method POST return nothing
print (json_encode("The POST didn't return any values")); //Return a json string, so the dart script can interpret the error