mirror of
https://github.com/crazybber/go-pattern-examples.git
synced 2024-11-26 21:56:02 +03:00
59 lines
1.3 KiB
Go
59 lines
1.3 KiB
Go
package observer
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import (
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"context"
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"fmt"
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)
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//使用RSS邮件订阅的例子
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//某科技论坛更新时候，通过邮件通知订阅该版块的用户关注更新.
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type updates struct {
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topic string
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order int
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}
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//TechBBS 科技论坛，是发送通知的主体
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type TechBBS struct {
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mailObservers []IMailReceiver ///邮件订阅该板块动态的用户
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context context.Context ///更新的上下消息，其实就是一堆参数了
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}
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//IMailReceiver 邮件接收者就是订阅更新的用户
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type IMailReceiver interface {
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Notice(context.Context)
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}
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//Registry 提供给用户通过邮件注册获取/订阅更新动态的能力
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func (t *TechBBS) Registry(receiver IMailReceiver) {
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t.mailObservers = append(t.mailObservers, receiver)
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}
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//SetConext 设置更新内容的上下文
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func (t *TechBBS) SetConext(ctx context.Context) {
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t.context = ctx
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}
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//notifyUpdate 通知订阅用户，我更新了，你们可以来看了
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func (t *TechBBS) noticeAllUpdate() {
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for _, m := range t.mailObservers {
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//逐个通知
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m.Notice(t.context)
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}
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}
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//User 用户
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type User struct {
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name string
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}
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//Notice 用户收到订阅通知
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func (u *User) Notice(ctx context.Context) {
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content := ctx.Value(updates{}).(updates)
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fmt.Printf("%s receive updates notice\n", u.name)
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fmt.Printf("updates order: %d content：%s\n", content.order, content.topic)
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}
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