[SOLVED] Passing a reference to a function

[jordanwb]

Let's say I have this class:

 

abstract class Theme
{
private static $themes;

public static function AddThemeCreator ($name, $reference_to_theme)
{
	Theme::$themes[$name] = $reference_to_theme;
}

public static function LoadTheme ($name)
{
	return new Theme::$themes[$name] ();
}
}

class SevenAreaTheme extends Theme
{
public function __construct ()
{

}
}

Theme::AddThemeCreator ('SevenAreaTheme', AddThemeCreator);

 

When php Passes "SevenAreaTheme" to Theme::LoadTheme, it returns an instance of the SevenAreaTheme class. I know you could do this in .Net with delegates, but it there something like this for PHP?

[Daniel0]

Maybe what you're looking for is the factory pattern?

 

http://en.wikipedia.org/wiki/Factory_method_pattern

[jordanwb]

Yes that's what I'm looking for. I don't want to use switches because I want the code to be dynamic. For example in the database there's a settings table which has a field called "DefaultTheme", this contains a string which could contain the value "SevenAreaTheme", the script gets the value from the table, passes it to Theme::LoadTheme, and returns an instance of that theme.

[Daniel0]

How about this? It would be a factory implementation.

 

abstract class Theme
{
    static public function factory($type)
    {
        $class = $type . 'Theme';
        if (!class_exists($class)) {
            throw new Exception("Theme doesn't exist");
        }
        
        return new $class;
    }
}

class SevenAreaTheme extends Theme
{
    // bla bla
}

[jordanwb]

Sweet, that works. I didn't think that something like that would work, but it does. One question, would that be considered bad style? I mean the "return new $class;" part.

[Daniel0]

Not at all. Otherwise I would've never suggested it

[jordanwb]

Fair Enough.  Thanks.