PHP - Help Setting Up Path Constants

I've been working on a registration form and it seems like the better I get at solving more complex issues the smaller issues plague me the most.

I've got the following function:

//process database actions
function process_database($post) {
  global $table;

  //connect to database
  $connect_db = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

  //check database connection
  if ($connect_db->connect_error) {
    return false;
  } else {
    if ($stmt = $connect_db->prepare( "INSERT INTO $table (firstname, lastname, username, email, password) VALUES ( ?, ?, ?, ?, ? )" ) ) {
      $stmt->bind_param(NULL, $firstname, $lastname, $username, $email, $password);

      $firstname = $post['firstname'];
      $lastname = $post['lastname'];
      $username = $post['username'];
      $email = $post['email'];
      $password = $post['password'];

      if (!$stmt->execute()) {
        return false;
      }
    } 
  }

  return true;
}

This is in a functions.php file. The issue is in the $connect_db assignment that has the constants from the config.php file in it.

That file looks like this:

<?php
ob_start();
session_start();

$timezone = date_default_timezone_set("America/xxxxxxx");

$whitelist = array('username', 'email', 'email2', 'password', 'password2');
//TODO here I've removed firstname and lastname from the whitelist as they're optional
//may add them back and try to iterate around them in the future

$table = 'users';

define('DB_HOST', 'localhost');
define('DB_USERNAME', 'root');
define('DB_PASSWORD', '');
define('DB_NAME', 'means');

$conn = mysqli_connect(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

if($conn->connect_errno) {

    printf("Connect Failed: %s\n", $conn->connect_error);
    exit();
    
}

ob_end_flush();
?>

The constants defined in config.php are not being recognized in functions.php. I understand that constants are global and available throughout a script.

I've connected to two files with the following line:

//require config file
require_once($_SERVER['DOCUMENT_ROOT'] . '/../config/config.php');

as I have the config/config.php outside htdocs. I know this works because of a db query to check uniqueness of username that works properly.

Why are these constants coming back as undefined in the process_database().function.php? Nothing I've tried works and I've run out of ideas. TIA

echo “here is a class constant: self::CLASS_CONSTANT”; // using double quotes

echo ‘here is a class constant: ‘ . self::CLASS_CONSTANT;

echo “my name is $name_variable”;

I have defined my database connection data as constants in a separate file for security reasons.  How can I simply access the data stored in those constants.  I have to call the file to get the value of the constants.  If I inadvertently call the file twice in a script  using an include or require statement, I get an error that I am trying to define the constants again.  Can I somehow just call the constants without including the file where they are defined?

--Kenoli

I sometime pass configuration settings as an associate array... 

public function __construct(JsonValidatorMethods $methods, array $options) {
    foreach($options as $option) {
        //validate whether valid and if so set $this->$option.  Options not provided will default to their private $strictMode=true value
    }
}
$validator=new JsonValidator($methods, ['sanitize'=>true, 'strictMode'=>true, 'setDefault'=>false]);

And other times pass them as individual arguments...

public function __construct(JsonValidatorMethods $methods, bool $sanitize=false, bool $strictMode=false, bool $setDefault=true) {}
$validator=new JsonValidator($methods, true, true, false);

I have a class which I was doing the later and also which I wish to allow them to be first set in the constructor but also specified when calling some of the public methods.  It became a pain to pass all the individual flags to each private method, so I thought I would give bitmask constants a try as shown below.

I recognize that this approach only allows booleans to be passed, but I am okay with this.  The part I am not sure about is how best have default values.  For instance, maybe the default is $this->options=0b0110, 0b1100 is passed to the constructor, and 0b1 (aka 0b0001) is passed is passed to the public method.  The high three bits in 0b0001 just are not provided, but how can I not interpret them as explicitly false?

Also, a little off topic, but am I implementing this bitmask approach correctly, and any strong options whether one of these three approaches or some totally other approach is best?

Thanks

class JsonValidator
{
    //Use provided options
    const SANITIZE      =   0b0001;   //Whether to sanitize (i.e. 'false' is changed to false)
    const STRICTMODE    =   0b0010;   //Currently only enfources that boolean is true/false (instead of 1/0 or "true"/"false")
    const SETDEFAULT    =   0b0100;   //If true, type double and value "nan" will be converted to 0, etc.

    private $methods, $options;

    static public function create(int $options=0):self {
        return new self(new JsonValidatorMethods, $options);
    }

    static public function getOption(array $options):int {
        $o=0;
        foreach($options as $option) {
            if(!defined("self::$option")){
                throw new JsonValidatorErrorException((is_string($option)?$option:'given constant').' is not valid');
            }
            $o=$o|constant("self::$option");
        }
        return $o;
    }

    public function __construct(JsonValidatorMethods $methods, int $options=0) {
        $this->methods=$methods;
        $this->options=$options;
    }

    public function validate(array $input, array $rules, int $options=0){

        $options=$options|$this->options;

        if($options & self::SANITIZE) {
            $value=$this->sanitize($input, $rules, $options);
        }
    }

    private function sanitize(array $input, array $rules, int $options=0){}
}

$validator=new JsonValidator($methods, JsonValidator::SANITIZE|JsonValidator::SETDEFAULT);

define ('ASSETS_PATH', base_url().'assets/');
define ('UPLOAD_URL', base_url().'uploads/');

href="<?php echo ASSETS_PATH; ?>css/mycss.css"

<a href="<?php echo UPLOAD_URL;?>images/myupload01.jpg" ><img src="<?php echo UPLOAD_URL;?>images/myupload01.jpg" /></a>