过滤整个$ _POST变量 - 这是安全的吗？

I'm trying to make an easy way to clean all input data from forms. Does this code make sense? And is it safe?

    public function filter( $data )
    {
        if( !is_array( $data ) )
        {

            $data = trim($data);
            $data = mysqli_real_escape_string( $this->link, $data );
        }
        else
        {
            //Self call function to sanitize array data
            $data = array_map( array( 'DB', 'filter' ), $data );
        }
        return $data;
    }

$_POST = $database->filter($_POST);
//will all post variables now be safely escaped?