Design pattern Learning-Simple Factory mode

Simple Factory mode:

The essence of the simple factory model is that a factory class dynamically determines which product class (these product classes inherit from a parent class or interface) should be created, based on the parameters passed in.

Note: Strictly speaking, the simple Factory mode is not a design mode, but it is often used. It has the advantage of decoupling the product creation from the use of the product and processing it separately.

Part of the pattern:

• One user: (Pizzastore in the case)
• A simple factory class: Responsible for creating products
• A set of product classes: (in the case of the abstract pizza class and its specific implementation subclass)

The UML class diagram is as follows:

The specific implementation of the case code:

1, Product user class:

 class   Pizzastore { //  contains an abstract class for a product and a simple factory  var pizza:pizza = = Simplepizzafactory () 
     //  provide pizza method   Func Orderpizza (pizzatype:pizzatype) { //  Create products from simple Factory (Pizza)  Pizza = Simplepizzafactory.createpizza (Pizzatype)   //  product behavior   Pizza.prepare () Pizza.bake () Pizza.cut () Pizza.box ()}}  

2, Simple factory class

class simplepizzafactory {    = Pizza ()        //  Create Pizza (create different Pizza with different parameters)    func Createpizza (Pizzatype:pizzatype), Pizza {        switch  pizzatype {        case  Pizzatype.cheese:            = Cheesepizza ()        case  Pizzatype.clam:             = Clampizza ()        }                return  Pizza    }}

3. Product class: (contains abstract classes and their specific implementation classes)

classPizza {var name:string=""var dough:string=""var sauce:string=""var toppings:[string]= []        //preparing the Pizza methodFunc Prepare () {println ("preparing for \ (name) ...") println ("tossing dough ...") println ("Adding sauce ...")         forTopping:stringinchToppings {println ("\ (Topping)")}}} Func box () {println ("packing ... \ n")} func Bake () {println ("baking ...")} func cut () {println ("cropping ...")    }}classCheesepizza:pizza {Overrideinit () {super.init () Self.name="Cheese Pizza"Self.dough="Thin crust Dough"Self.sauce="Marinara Sauce"Toppings.append ("grated Reggino Cheese")    }}classClampizza:pizza {Overrideinit () {super.init () Self.name="Clam Pizza"Self.dough="Low crust Dough"Self.sauce="Cherry Sauce"Toppings.append ("grated Reggino Clam")    }}

4. Test code

Let Pizzastore = pizzastore ()//  get a Cheese Pizza Pizzastore.orderpizza from Pizzastore( Pizzatype.cheese)//  get a Clam PizzaPizzastore.orderpizza (Pizzatype.clam) from Pizzastore

5. Test results

Design pattern Learning-Simple Factory mode