On Tue, Feb 07, 2012 at 09:02:00PM +0000, Tim Streater wrote: > On 07 Feb 2012 at 19:34, Daniel Brown <danbrown@xxxxxxx> wrote: > > > On Tue, Feb 7, 2012 at 13:56, Mike Mackintosh > > <mike.mackintosh@xxxxxxxxxxxxxxx> wrote: > >> I was curious to see what everyones favorite design patterns were, if you use > >> any, and why/when have you used it? > >> > >> Choices include slots and signals (observer), singleton, mvc, hmvc, factory, > >> commander etc.. > > > > Mine is apparently CPSV (Commentless Procedural Spaghetti Vomit), > > as that's what I encounter no less than 80% of the time in the wild. > > Since I have no idea what anyone is talking about, I can only conclude that you're playing Mornington Crescent (q.v.), on a non-standard board. > > -- > Cheers -- Tim > Design Patterns are Way Nifty Kewl patterns of code which are supposed to facilitate certain types of operations. (Was that sarcasm you detected? Yes it was.) For example, the Singleton pattern. Let's say you had a configuration class that held the configuration values for your application, and you wanted to make sure there was only one object of that class instantiated, no matter how many times it was called in your code. You'd arrange the code and call the class in a certain way to ensure that only one object of that class resulted. To make your configuration class a "singleton", you'd probably make the class have a *private* constructor (so no outside routine could call it), and then provide a method called get_instance() which tested for the existence of an object of that class. If such an instance was found, someone calling configuration::get_instance() would simply get the existing object returned to them. Otherwise, configuration::get_instance() would instantiate the class and then return the new object to the caller. As you can see, that's a peculiar way of setting up your code for a specific purpose. Other design patterns do other things and dictate setting up things in other ways. The definitive work on this (and where it first gained the most publicity) is a book called "Design Patterns" by four authors (Gamma, Helm, Johnson and Vlissides). It essentially contains a chapter about each (known at the time) design pattern and some pseudocode about how it might be constructed. I imagine the authors looked at a lot of code and discovered that programmers were coming up with code that, in each case was remarkably similar for solving certain types of programming problems. So they codified what that found and wrote a book about it. I have the book on my shelf, and it's decent technology, but you could spend your whole career and never use any of it, and get along just fine. Paul -- Paul M. Foster http://noferblatz.com http://quillandmouse.com -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
