Question

What is the best way to make a variable accessable to all classes.

For example, I want to have a configuration file (Call it config.php) that is going to have a variable like so:

$server_url = "www.myaddress.com";

And I have a main library type file that contains a bunch of classes that need to access the $server_url. So here begins that main library file:

require 'config.php';

class one {
  function a() {
          $html = "<a href='$server_url/main.php'>LINK</a>"
         return $html;
         } 

  function b() {
        $html = "<a href='$server_url/about.php'>LINK</a>"
        return $html;

         }
}


class two {

    function new() {
          $html = "<a href='$server_url/blah.php'>LINK</a>

     } 
}

What would be the best way to make $server_url from the config.php available to every function? Or at least available to all the functions in a class?

Answer 1

Personally I would use a static entity to hold all configuration values.

Usually, most php applications have a single entry point (index.php) that can load up the config.php file and make the static entity available from that point.

If your application has multiple entry points, then you will need to include config.php in each of these points.

Something like this:

<?php
    class Configurator{
        private static $_configuration = array();
        public static function write($key, $value) {
            self::$_configuration[$key] = $value;
        }
        public static function read($key) {
            return self::$_configuration[$key];
        }
    }
    Configurator::write('server', 'http://localhost');
    Configurator::read('server');
 ?>

CakePHP has a similar class: http://api.cakephp.org/view_source/configure/