Best way to retrieve data in custom api extended from wp-api

Found answer to my question.

I didn’t want to specify each data parameter in the function definition as it could get long. Therefore, I am retrieving them using $_POST global variable.

I know thats not a good solution, if you know any better let me know.

public function create_document($_files = null){

    if(!empty($_files)) {
        // process file

    $data = $_POST;
    // process $data is you want

    // $data['doc_id']
    // $data['case_reference']