finish strategy

behavior/15_strategy/README.md

@@ -1,4 +1,9 @@
 # 策略模式
 
-定义一系列算法，让这些算法在运行时可以互换，使得分离算法，符合开闭原则。
+策略模式是定义一系列具有相同签名的接口方法，让这些方法在运行时可以互换.
 
+通俗的讲就是同一个函数、动作、行为等接口，在不同类型的对象上有不同的实现，所以，以在运行替换，这也非常符合开闭原则.
+
+常用的例子是计算加减乘除,这里用一个存款的例子，大陆居民用人民币存款,香港居民用港币.
+
+向银行执行存款动作时候，给出的现金钱是不同的类型,大陆居民拿出人民币，香港居民拿出港币.

behavior/15_strategy/strategy.go

@@ -2,44 +2,53 @@ package strategy
 
 import "fmt"
 
-type Payment struct {
-	context  *PaymentContext
-	strategy PaymentStrategy
-}
+//money kind
+const (
+	RMB = "RMB"
+	HK  = "HK"
+)
 
-type PaymentContext struct {
-	Name, CardID string
+//StoreContext for Store 要包存钱的上下文信息
+type StoreContext struct {
+	Kind, CardID string
 	Money        int
 }
 
-func NewPayment(name, cardid string, money int, strategy PaymentStrategy) *Payment {
-	return &Payment{
-		context: &PaymentContext{
-			Name:   name,
-			CardID: cardid,
-			Money:  money,
-		},
-		strategy: strategy,
-	}
+//IStore 要实现的存钱接口
+type IStore interface {
+	Store(*StoreContext)
 }
 
-func (p *Payment) Pay() {
-	p.strategy.Pay(p.context)
+//MainLandCitizen 大陆居民
+type MainLandCitizen struct{ Name string }
+
+//Store Money  to bank
+func (m *MainLandCitizen) Store(ctx *StoreContext) {
+	fmt.Println("i am: ", m.Name, "i want to store: ", ctx.Money, ctx.Kind, "to: ", ctx.CardID)
 }
 
-type PaymentStrategy interface {
-	Pay(*PaymentContext)
+//HongKongCitizen 香港居民
+type HongKongCitizen struct{ Name string }
+
+//Store Money  to bank
+func (h *HongKongCitizen) Store(ctx *StoreContext) {
+	fmt.Println("i am: ", h.Name, "i want to store: ", ctx.Money, ctx.Kind, "to: ", ctx.CardID)
 }
 
-type Cash struct{}
-
-func (*Cash) Pay(ctx *PaymentContext) {
-	fmt.Printf("Pay $%d to %s by cash", ctx.Money, ctx.Name)
+//Bank handle moneyholder
+type Bank struct {
+	moneyHolder IStore
 }
 
-type Bank struct{}
-
-func (*Bank) Pay(ctx *PaymentContext) {
-	fmt.Printf("Pay $%d to %s by bank account %s", ctx.Money, ctx.Name, ctx.CardID)
-
+//Recept a user
+func (b *Bank) Recept(moneyHolder IStore) {
+	b.moneyHolder = moneyHolder
+	fmt.Println("Bank: ", "Recept a New User")
+}
+
+//AccountUserMoney 动态替换的过程在这里,这里调用任何实现了Store的接口对象
+//AccountUserMoney to handle User's Money
+func (b *Bank) AccountUserMoney(ctx *StoreContext) {
+	b.moneyHolder.Store(ctx)
+	fmt.Println("Bank: ", "Processing Store", ctx.Money, ctx.Kind, "to: ", ctx.CardID)
 }

behavior/15_strategy/strategy_test.go

@@ -1,15 +1,25 @@
 package strategy
 
-func ExamplePayByCash() {
-	payment := NewPayment("Ada", "", 123, &Cash{})
-	payment.Pay()
-	// Output:
-	// Pay $123 to Ada by cash
-}
+import "testing"
 
-func ExamplePayByBank() {
-	payment := NewPayment("Bob", "0002", 888, &Bank{})
-	payment.Pay()
-	// Output:
-	// Pay $888 to Bob by bank account 0002
+func TestStoreMoney(t *testing.T) {
+
+	bank := Bank{&MainLandCitizen{"Miss White"}}
+	ctx := &StoreContext{
+		Kind:   "RMB",
+		CardID: "12345678921",
+		Money:  10000,
+	}
+	bank.AccountUserMoney(ctx)
+
+	hkUser := &HongKongCitizen{"Miss Black"}
+
+	bank.Recept(hkUser)
+
+	ctx = &StoreContext{
+		Kind:   "HK",
+		CardID: "987345678456",
+		Money:  8723,
+	}
+	bank.AccountUserMoney(ctx)
 }