factory-pattern

After listening to the Clean Code Talks , I came to understand that we should use factories to compose objects. So, for example, if a House has a Door and a Door has a DoorKnob , in HouseFactory we create a new DoorKnob and pass it to the constructor of Door , and then pass that new Door object to the constructor of House . But what about the class that uses the House (say the class name is ABC ) ? It will depend on the HouseFactory , right? So do we pass the HouseFactory in the constructor of ABC ? Won't we have to pass a whole lot of factories in the constructor that way? Staying with the

I have been reading Effective Java by Joshua Bloch and so far it really lives up to its reputation. The very first item makes a convincing case for static factory methods over constructors . So much that I began to question the validity of the good old constructors :). The advantages/disadvantages from the book are summarized below: Advantages: They have names! We have total instance control (Singletons, performance, etc.) They can return a subtype/interface Compiler can provide type inference Disadvantages: Private classes cannot be subclassed They do not stand out in the documentation as

What is the best method for using singleton design pattern in conjunction with the factory method pattern in PHP5? My simplest usage scenario for this is instantiation selective database connection only once for each database type. singleton factory for DB connection: class Registry { private static $_objects; public static function set($key, $object) { if (!array_key_exists($key, self::$_objects)) self::$_objects[$key] = $object; } public static function get($key) { if (array_key_exists($key, self::$_objects)) return self::$_objects[$key]; else return false; } } class DBFactory { public

How to make Ninject to instantiate object based on variable on run time?. I am trying to inject the correct Repository in The Controller action - MVC 3 - based on parameter come from user input. If user input "BMW" it would bind ICarRepository to BMWRepository , and if he input "KIA" KiaRepository will be injected. [HttpPost] public ActionResult SearchResult(FormCollection values) { string carModel = values["model"]; ICarRepository myRepository = RepositoryFactory.getRepository(carModel); ..... } This is known by switch/case noob instantiation or Parameterized Factories, and i know how to do

This question already has answers here : What is an efficient way to implement a singleton pattern in Java? [closed] (29 answers) This is the first time I am writing a Factory class. Below is my Factory class, I am not sure whether this is the correct way of making thread safe Singleton Factory class or not. I will be returning instance of my Client using this factory? public class ClientFactory { private static ClientFactory instance = null; private ClientFactory() { } public static ClientFactory getInstance() { if (instance == null) { instance = new ClientFactory(); } return instance; }

I am trying to use a factory pattern to create a QuestionTypeFactory where the instantiated classes will be like MultipleChoice, TrueFalseQuestion etc. The factory code looks something like this class QuestionFactory { public enum QuestionType { TrueFalse, MultipleChoice, Essay } public static Question createQuestion(QuestionType quesType) { switch (quesType) { case TrueFalse: return new TrueFalseQuestion(); case MultipleChoice: return new MultipleChoiceQuestion(); case Essay: return new EssayQuestion(); } throw new IllegalArgumentException("Not recognized."); } } This works ok for now. If I