golang 设计模式 observer_test 代码实现
package observer
func ExampleObserver() {
subject := NewSubject()
reader1 := NewReader("reader1")
reader2 := NewReader("reader2")
reader3 := NewReader("reader3")
subject.Attach(reader1)
subject.Attach(reader2)
subject.Attach(reader3)
subject.UpdateContext("observer mode")
/ Output:
/ reader1 receive observer mode
/ reader2 receive observer mode
/ reader3 receive observer mode
}