PHP variables lifetime

Barguast

I have a PHP file called config.inc.php which read an XML-format configuration file into a varible - $config - using SimpleXML. I 'require' on every other page that needs access to the configuration file. However, I find that I am having problems with this.

If I do:

require 'config.inc.php';

class Test
{
    public function UseConfig()
    {
         var_dump($config);
    }
}

Then I find that $config is not accessible. If I put another require inside the UseConfig function then all works well, but for some reason it won't work as above. This wouldn't be a problem, except that I don't want to have to continually reread the configuration file everytime I want to access it.

Is this PHP getting rid of the SimpleXML object prematurely, or is there something amiss with my PHP knowledge? Please let me know! :p

Thanks

NogDog

Functions (and therefore class methods) have their own private name space. So variables used within those functions are locally scoped only to that function and are ignorant of any variables of the same name outside of that function. The exceptions to this are the "super-global" variables such as $GET and $SESSION, or variables within the function which are declared as "global".

In your case, in order to avoid the close-coupling that results from declaring a variable as global, I would recommend passing the $config variable to your class's constructor and store it as a class variable. Then the methods of that class would access it as a class member.

require 'config.inc.php';

class Test
{
    private $config;

public function __construct($config)
{
    $this-config = $config;
}

public function UseConfig()
{
     var_dump($this->config);
}
}

$testObject = new Test($config);