Php abstract class site configuration - php

Question

i have a config class which is an abstract class. I would like to set it up so it automatically detects which server the site is on and then assigns appropriate constants. I get an error on line ten $this->hostName = $_SERVER['SERVER_NAME']; expecting `T_FUNCTION.
What is the correct way to do this and is there a better way to do this? Here is the first part of my class
abstract class config{
public $hostName;
public $hostSlices;
public $domain;
echo $_SERVER['SERVER_NAME'];
//strips out the "www" from the server name but only if it has the name on it .
$this->hostName = $_SERVER['SERVER_NAME'];
$this->hostSlices = explode(".",$this->hostName);
if($this->hostSlices[0]=="www"){array_shift($this->hostSlices);}
$this->domain = join(".",$this->hostSlices);
//depending on which domain is used, different config setup is used.
switch ($this->domain){
case "localhost":*/
const HOST = "localhost";//would http://localhost/ work as well. In that case, then this and the SITE_ROOT could be the same variable and i would preferentially set them depending on the host that the site is on.
const USER = "root";
const PWD = "xxxxxxx";
const NAME = "hurunuitconz";//database name
//public $name = "hello from the config class";//you cannot access variables from an abstract class you should define constants and then the can be used anywhere
###########Location of file groups########
const SITE_ROOT = "http://localhost";
const ADMIN_IMAGES = 'http://localhost/images/user_images/admin_images';
break;
case "charles.hughs.natcoll.net.nz":
const HOST = "charles.hughs.natcoll.net.nz";//would http://localhost/ work as well. In that case, then this and the SITE_ROOT could be the same variable and i would preferentially set them depending on the host that the site is on.
const USER = "charles_andrew";
const PWD = "xxxxxxx";
const NAME = "charles_hurunuitconz";//database name
###########Location of file groups########
const SITE_ROOT = "http://charles.hughs.natcoll.net.nz/_Assignments/Industry/www";//this is just confusing the way natcoll makes us do this.
const ADMIN_IMAGES = 'http://charles.hughs.natcoll.net.nz/_Assignments/Industry/www/images/user_images/admin_images';
break;
}

Answer 1

An abstract class shouldn't allow you to set private data (only an inherited concrete class).
Also, take a look at this link in stackoverflow for an interesting discussion on SERVER_NAME vs. HTTP_HOST

Answer 2

You have to wrap all that code in a constructor or better yet a function called init() or somthing. Then when you override init in the child classes you would call parent::init(). Did you mean to make this class static, not abstract?

Answer 3

The way you're structuring your code is just not right. PHP does allow for many crazy things, but defining constants and outputting code as a part of an abstract class makes no sense whatsoever in terms of OOP.
What you probably mean to do is to have a helper class that defines configuration settings based upon the local server name. To do so, you have a couple options:
Option 1) Create a regular class with a constructor.
class Config {
public $x;
public $y;
public function __construct() {
switch (...) {
$this->x = 2;
$this->y = 3;
}
}
}
And use it like this:
$config = new Config();
echo "Variable y: " . $config->y;
Option 2) Static method in an abstract class.
abstract class Config {
public $boolInitialized = false;
public static function init() {
if (self::$boolInitialized) {
return;
}
self::$boolInitialized = true;
switch (...) {
self::$x = 1;
self::$y = 2;
}
}
public static function getX() {
self::init();
return self::$x;
}
}
And use it like this:
echo Config::getX();

Answer 4

You cant output something in a class without declaring first a method
this will fail
abstract class fo
{
public $fo;
echo $fo;
}
**but this will work**
abstract class fo
{
public $fo;
public function __construct()
{
$this->fo = $_SERVER['SERVER_NAME'];
}
public function sayFo()
{
echo $this->fo;
}
}