You can use if ( Input::has('parameter') )
to check for the existence of a certain parameter in the POST, or you can pass a default into the function, and then test if it's there.
$parameter = Input::get('parameter', false);
if ($parameter)
{
// do something with the data
}
else
{
// it's not present in the POST
}
To check for the presence of any data at all:
$data = Input::all();
if (count($data) > 0)
{
// there is data in the POST
}
else
{
// there is no data in the POST
}
Note - You can access the data from any HTTP verb (GET, POST etc) using the same Input::get('data')