Sharing variables between classes when including files - php

Question

stuck on this. Lets start with code.
Settings.php
class settings{
public $db_host;
public $db_username;
public $db_password;
public $db_database;
public function db_settings(){
/*$db_host = "localhost";
$db_username = "root";
$db_password = "";
$db_database = "eveonline";*/
$this->db_host = "localhost";
$this->db_username = "root";
$this->db_password = "";
$this->db_database = "eveonline";
}
This is where I want to use this
class xmlUpdate{
include_once ('./lib/settings.php'); //This wont work
public $itemCount;
public function dbItemCount(){
include_once ('./lib/settings.php');// This will work, but only in this function
In this case its for database varables, so I dont have to duplicate code whenever I want to make a database connection.
How can I use the database varables in another class, the whole class, not just the function where it allows me to include?

Answer 1

I would put the include into the __construct() function of your class, instantiate a new Class, read out the variables put them in local variables in your class.
class xmlUpdate{
public $db_host;
public $db_username;
public $db_password;
public $db_database;
function __construct(){
include_once('./lib/settings.php');
$settings = new settings();
$this->db_host = settings->db_host;
$this->db_username= settings->db_username;
$this->db_password= settings->db_password;
$this->db_database= settings->db_database;
}
}
Or you could make you xmlUpdate class extend the settings class.

Answer 2

This might be a possible approach, the Database class could also have connect and disconnect, query etc. function. Write a __autoload function so you don't have to include any files. Another simple approach would be to define all the data in the index.php -> define('DB_HOST', 'localhost'); and later access it via DB_HOST.
class DataBase {
private static $instance = null;
public $db_host;
public $db_username;
public $db_password;
public $db_database;
private function __construct() {
$this->db_host = "localhost";
$this->db_username = "root";
$this->db_password = "";
$this->db_database = "eveonline";
}
private function __clone() {
}
public static function getInstance() {
if (self::$instance === null) {
self::$instance = new DataBase;
}
return self::$instance;
}
}
class Xml {
protected $db;
public function __construct() {
$this->db = DataBase::getInstance();
}
public function getUsername() {
return $this->db->db_username;
}
}
// test
$xml = new Xml;
print $xml->getUsername() . "\n";

Answer 3

you could make them static or follow a singleton pattern

Answer 4

I think that what you're trying to do is have some GLOBAL type of thing you can access from anywhere.
As the user busypeoples suggests, you could try using the singlton pattern if you want to include some complicated behavior for the database like connections. Look up the singleton pattern and you should definitely be able to find some PHP specific examples.
If all you want to do is share some simple connection string, password and user for the database then you can use the define statement.
//the db_info.php file
define( 'DB_NAME', 'mydevdatabase' );
define( 'DB_IP', '127.0.0.1' );
define( 'DB_USER', 'bob' );
define( 'DB_PASSWORD', 'password' );
Afterward, you can just include this file at the beginning of any PHP file and use the constants.
//some other php file
require_once( 'db_info.php' );
class Test
{
public function tester()
{
$some = DB_IP;
$other = DB_USER;
//your other code
}
public function otherfunction()
{
$some = DB_IP;
$other = DB_USER;
//your code
}
}