Re: OO and "Singleton" class

On Tue, Sep 01, 2009 at 06:06:24PM -0400, Eddie Drapkin wrote: > On Tue, Sep 1, 2009 at 5:16 PM, Paul M Foster<paulf@quillandmouse.com> wrote: > > > > I'm a little fuzzy on some of the PHP implementation details for some > > stuff. In PHP (5 <= phpversion() < 5.3), I'd like a configuration class > > which can only effectively be instantiated once. Will the following code > > do this? Any other suggestions or corrections? (Code is untested. Feel > > free to complain about syntax.) <snip> > > The primary thing you need to do to make a class a singleton is > disallow the instantiation of a class directly. Which means using > visibility, which is conspicuously absent from your example above. > > So, to prevent normal instantiation, we make the constructor private. > Also, we need a method to retrieve the instance. Static members serve > this purpose: Good explanation. Thanks. I'll try it out. Paul -- Paul M. Foster