::getInstance() - what is it for?

[Arty]

I see that many classes in XenForo have static function getInstance() and store its instance statically.

Is it simply a way to call non-static methods of that class without initializing more than one instance of same class? Or could it be used for something more complex?

 

[tyteen4a03]

Yes, it's to ensure only one instance is created. Doesn't make sense to have two XenForo_Session instances during the same run.

As for more advanced usage, you can make some fancy boilerplate code to make a self contained class where it manages its own instances, but I have yet to see real life usage.

 

[euantor]

To add to @tyteen4a03's post, this design pattern is called the singleton pattern: http://en.wikipedia.org/wiki/Singleton_pattern