Question

I have one main class “main”, which I use to store the configuration and a few objects. However, I am unable to access the objects & variables in a class which extends main, through $this.

Here is some of my main class:

<?php
class main{
    // the configuration vars
    public $config = array();
    // the current user variables
    public $uid; // contains the user ID
    public $gid; // contains the group ID
    // database variables
    public $DB; // contains the connection
    public $query_id; // contains the query ID
    public $query_count; // how many queries have there been?
    // cache variables
    public $cache;
    // start up functions
    public function startup(){
        // first, set up the caching
        if(function_exists('memcache_connect') AND $this->config['use_memcache'] == true){
            // start up memcache
            require_once('memcache.class.php');
            $this->cache = Cache::getInstance();
        }
        // now, set up the DB
        $this->connectToDatabase();
        // now, set up the user session
        $this->setUserSession();
        // are we logged in? If so, update our location
        if($this->uid > 0){
            // update location
            $this->updateUserSession();
        }
    }

Here is an example of another class

<?php
class user extends main{
        public function viewProfile($uid){
                exit($this->config['session_prefix']); // displays nothing
                if($this->cache->exists('key')){ // fails

The $config value is correctly set up, and I can read it within main but not any sub class.
The $cache->exists object just results in Call to a member function exists() on a non-object.

On index.php, the classes are loaded and set up. The Main class is setup first, and the startup function is called. The configuration array is passed before startup is called.

Can anyone suggest how I can fix this?

Answer 1

Are you sure your array is correctly set up.

This simple test works for me:

<?
class main {
    public $test = "Woot";
}

class test extends main {
    public function __construct() {
        echo $this->test;
    }
}

$t = new test();

Just for testing purposes, add a variable $test like in my example to the class main and try to echo it in the user constructor.

I would check if your cache is really set up correctly.
Probably the error is in this if statement:

if(function_exists('memcache_connect') AND $this->config['use_memcache'] == true){

One of these two conditions isn’t met, so your $cache variable won’t get initialized.