What this code mean ?

[Welliam]

In the grids examples (popup editing) I found this code but I dont know why it used like that please explain.

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

    header('Content-Type: application/json');

 

    $request = json_decode(file_get_contents('php://input'));

[DavidOBrien]

Read this :)

http://php.net/manual/en/wrappers.php