On Tue, 2010-01-19 at 12:30 -0500, Paul M Foster wrote: > On Tue, Jan 19, 2010 at 03:11:56PM +0000, Ben Stones wrote: > > > Hi, > > > > I've been learning about object oriented programming for the past few weeks > > and I've understood it pretty well, but I have one question. Usually with > > PHP scripts I make, all the functionality for a specific page is in the > > actual PHP file, and I'd use PHP functions in a separate directory which > > would be included in whichever PHP file needs specific functions I have > > created. The functions would be for the specific things in my script, such > > as validation checks, functionality that will be used/repeated a lot > > throughout my script, etc. What I don't understand about OOP is what its > > primary purpose is for. Do I use OOP for all the functionality of my > > application, in separate directories, and include these specific class files > > and call the methods to complete specific functionality needed for whatever > > PHP file I'm working on, or is OOP used for specific functionality like I > > would with functions? Essentially what I'm asking is what is the primary > > purpose for OOP? Hope you understand. > > <opinion> > > OOP is a *trend* or *fad* in programming. You can create a whole > application written almost entirely with OOP. It will usually follow the > MVC (Model-View-Controller) paradigm. It will have a front controller > (one page that every other page starts from) and distribute the work of > displaying pages, validating values, and storing data across a variety > of classes in a bunch of files. See a package called CodeIgniter for a > good but simple example of this paradigm. Generally, an application > written this way will load many tens of pages' worth of code before any > byte gets to the screen. > > Alternatively, you can write simple OOP components for selected parts of > your application. For example, if you're dealing with a bunch of > customer screens, you can write an object oriented class which handles > all the customer queries with the database. > > There are a variety of arguments that OOP advocates will make in favor > of OOP. It's *supposed* to make your programming easier and faster, and > make for easier debugging. In the real world, this may or may not be > true. OOP does work to reduce the clutter in your namespaces-- the > names of methods within classes are hidden from the rest of your > namespace, unlike global functions. It also relieves you from having to > pass a lot of parameters to each routine you call; you can store a lot > of properties in the class, and they are shared with the methods in the > class. > > One of the more serious problems I've seen with OOP lies with classes > which have dependencies on other classes. It's like walking a minefield > sometimes, ensuring that this class gets instantiated before that one, > which depends on it. You can write an incredibly complicated automatic > instantiator which instantiates classes and ensures they fire in the > proper order (I have), but it seems kind of silly when you could just as > easily write external functions which perform similar functions. > > </opinion> > > Bottom line is, study OOP (look it up in wikipedia.org), and if you > think its advantages are worth your effort to learn the new paradigm, go > with it. But ignore the hype (and there's a lot of it). Do what works > for you. > > <suit status=on type=flame-retardant> > > Paul > > -- > Paul M. Foster > I wouldn't call OOP a fad really, as that suggest a silly short-term trend, but you do bring up a good point about class dependency problems. If dependencies are causing that sort of level of problem, then it might be worth re-making part of the wheel (after all, you wouldn't see wooden cart wheels on a Ferrari, would you?!) I've seen plenty of sites use no OOP at all, but I think once a system gets beyond a certain size, it does make more sense to use OOP, just to avoid running into problems where you have so many functions performing so many tasks but becoming a nightmare to maintain. Oh, and your flame suit failed because you forgot the quotation marks around the attribute values, and you didn't close the tag :p Thanks, Ash http://www.ashleysheridan.co.uk
