Hello,

I've been having a bit of trouble getting this to work, maybe I'm going about it the wrong way. What I am trying to do is take a variable from lets say config.php and use it in my database.class.php class file so I can centralise my options.

Putting an include to the config in the top of the database class doesn't seem to pull the vars into the class. Putting it just inside the class doesn't work either. How can I pull the config variables into use for the functions in this class?

For example...
config.php

$dbhost = "localhost" ;
$dbuser = "root" ;
$dbpass = "pass" ;

database.class.config

require_once "config.php" ;

class db {

     function connect(){
          
          mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to database. ')

     }

}

Hopefully that helps make things a bit clearer... I need connect() to be using the vars from config!

Cheers guys...

Leonard

The idea behind classes means that they have no concept of what is around them - they are contained objects and only care about what is contained within them.

In your situation the simplest thing to do would be to pass them in as parameters, either in the class instantiation or when calling the Connect method. Something like...

PHP Code:


//Config.php file include 

$dbhost = "localhost" ;
$dbuser = "root" ;
$dbpass = "pass" ;

class db {
     var $dbhost;
     var $dbuser;
     var $dbpass;

     function db($dbh, $dbu, $dbp)
     {
           $this->dbhost = $dbh;
           $this->dbuser = $dbu;
           $this->dbpass = $dbp;
     }

     function connect(){
          
          mysql_connect($this->dbhost, $this->dbuser, $this->dbpass) or die ('Error connecting to database. ')

     }

}

$db = new db( $dbhost, $dbuser, $dbpass );
$db->Connect(); 


That is a rough outline, it uses PHP4 constructs but you might want to make use of the much better PHP5 features for OO if your host supports it.

Stuart makes an excellent point! But for a direct answer, vars are not global (meaning that they are ignored with methods and objects) and you would have to invite them into the global scope in your function method:

PHP Code:

class db {
     function connect(){
          global $dbhost, $dbuser, $dbpass;
          mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to database. ')
     }
} 


Or, you can use constants which are static defined values which are auto global:

config:

PHP Code:

define('DATABASE_HOST' , 'localhost');
define('DATABASE_USER' , 'root');
define('DATABASE_PASS' , 'pass'); 


class:

PHP Code:

class db {
     function connect(){
          mysql_connect(DATABASE_HOST, DATABASE_USER, DATABASE_PASS) or die ('Error connecting to database. ')
     }
} 


Cheers guys thats really cleared up a lot of things in my head and given my knowledge a boost in the how classes work stakes.

Stoots method seems to work well (after a bit of getting my head round things. Out of interest do you guys think this is a better way then defining the needed vars as globals?

Thanks a lot for the help guys.

Building your class scripts without global dependancy is a great way to make your scripts more portable between applications. In other words, you can quickly copy that class script file into another project and have it running quickly without defining new vars.