ObServerDesignPattern

package main

import (
	"fmt"
	"log"
)

func MapDemo() {

	var r1 = make(map[string]string)
	r1["s"] = "s"
	//access map
	fmt.Println(r1["s"])

	//iterate map
	for key, value := range r1 {
		fmt.Println("Key:", key, "Value:", value)
	}
}

type SubjectModel struct {
	Marks        int
	ObserverList []*ObserverModel
}
type ObserverModel struct {
	SubjectModel *SubjectModel
	Marks        int
}

type Subject interface {
	AttachSubSuscriber()
	DetachSubSubsriber()
	GetState() int
	SetState(marks int)
	Notify()
}
type Observer interface {
	Update()
}

func (s *SubjectModel) AttachSubSuscriber(o *ObserverModel) {
	s.ObserverList = append(s.ObserverList, o)
}
func (s *SubjectModel) Notify() {
	for _, o := range s.ObserverList {
		o.Update()
	}
}
func (s *SubjectModel) SetState(m int) {
	s.Marks = m

}
func (s *SubjectModel) GetState() int {
	return s.Marks
}

//----------------------Observer
func (o *ObserverModel) SetSubject(s *SubjectModel) {
	o.SubjectModel = s
}
func (o *ObserverModel) Update() {
	if o == nil {
		log.Print("O is nil")
	} else {
		m := o.SubjectModel.GetState()
		fmt.Println("assa%v", m)
	}
}
func main() {
	var SubjectModel SubjectModel
	var ObserverModel ObserverModel
	(&ObserverModel).SetSubject(&SubjectModel)
	(&SubjectModel).AttachSubSuscriber(&ObserverModel)
	(&SubjectModel).SetState(12)
	(&SubjectModel).Notify()
	(&SubjectModel).SetState(120)
	(&SubjectModel).Notify()
}