You know, when coupling is not loose, components depend too much on each other. It makes your entire architecture fragile and immobile. You can check how loose the coupling is by making a unit test for a component. If you have no problem substituting dependencies by e.g. mock objects then everything is ok. Let take a model class. It depends on DB connection, here \Lib\Db\Adapter\Interfaceinstance. We cannot just create DB adapter instance within model constructor, because it depends on configuration data which doesn’t belong to the model.
Items in category refactoring
In my previous article among other patters I was telling about Flyweight. That is about the objects designed so to minimize memory use by sharing as much data as possible with other similar objects. You can find plenty of Flyweight implementation examples in Internet, though it will be mostly variations of Multiton, a collection (map) keeping only instance per every identical object. And I decided to follow that unwritten rule as it seems to be the simplest way to show the idea.
After having your project fully tested, deployed and running, it seems the application architecture is pretty good enough. All the requirements met and everybody is happy. But then as it happens, the requirements change and you, all of sudden, find yourself in the time of troubles. It comes out that some modules easier to hack than to modify. Change of other ones brings endless changes in a cascade of dependent modules.
Introduction Object oriented approach has been popular for a number of years. Its advantages can hardly be visible within short-term projects, yet any major long-term one simply cannot do without it. Object-oriented programming languages provide the tools necessary to present business logic in a demonstrable form. Today UML Class diagram (http://en.wikipedia.org/wiki/Unified_Modeling_Language) does suggest itself even on the stage of developing the system logic. Demonstrable business logic makes it easier for new participants to join in, helps to save time for those developers that come back into the project at later stages.