The Input class provides a connection to GET, POST, PATCH and PUT variables, URL segments and page numbers.

The best way to get the Input variable is to use the input() method of the Site class:

$input = Scriptor::getSite()->input();

Accessing GET, POST, PATCH, and PUT data

This is how you access the GET variable:

$username = $input->get->username;

Same thing for the POST, PATCH and PUT data:

$username = $input->post->username;
// $username = $input->patch->username;
// $username = $input->put->username;

If you access a variable that is not provided, then it returns null:

if (!$input->post->myCheckBox) {
    // the $_POST['myCheckBox'] is not provided