在使用@pinia/nuxt时，将HTTP请求放在setInterval之外会在每次setInterval迭代时执行。

Question

我正在尝试使用@pinia/nuxt和nuxt 3构建一个计时器。当计时器启动时，我还想发起一个HTTP请求来同步我的数据库。

我面临的问题是，每次我调用start动作时，都会为setInterval循环的每次迭代发起一次HTTP请求，而我只想运行一次。

这是pinia模块。我是在组件的onClick事件中调用start动作。

state: () => ({
  timer: {
    id: null,
    isRunning: false,
    time: 5,
    timer: 0,
    state: null,
  } as Timer,
}),
actions: {
  start() {
    this.timer.isRunning = true
    this.syncTimer()
    if (!this.timer.timer) {
      this.timer.timer = setInterval(() => {
        if (this.timer.time > 0) {
          this.timer.time--
        } else {
          clearInterval(this.timer.timer)
          this.reset()
        }
      }, 1000)
    }
  },
  stop() {
    this.timer.isRunning = false
    clearInterval(this.timer.timer)
    this.timer.timer = 0
  },
  reset() {
    this.stop()
    this.timer.time = 1500
  },
  syncTimer() {
    backendAPI<Timer>('/api/timer', {
      method: 'POST',
      body: this.timer
    }).then(({ error, data }) => {
      if (!error.value) {
        const id = data.value?.id ?? ""
        this.timer.id = id
        this.timer.state = "created"
      }
    })
  }
}

我的packages.json文件如下：

"devDependencies": {
    "@fortawesome/fontawesome-free": "^6.4.0",
    "@fullcalendar/core": "^6.1.8",
    "@fullcalendar/daygrid": "^6.1.8",
    "@fullcalendar/interaction": "^6.1.8",
    "@fullcalendar/timegrid": "^6.1.8",
    "@fullcalendar/vue3": "^6.1.8",
    "@iconify/vue": "^4.1.1",
    "@kevinmarrec/nuxt-pwa": "^0.17.0",
    "@mdi/font": "^7.2.96",
    "@nuxtjs/google-fonts": "^3.0.0",
    "@pinia-plugin-persistedstate/nuxt": "^1.1.1",
    "nuxt": "3.4.2",
    "sass": "^1.62.0",
    "vuetify": "^3.1.15"
  },
  "dependencies": {
    "@pinia/nuxt": "^0.4.11",
    "pinia": "^2.1.3",
    "vite-plugin-vuetify": "^1.0.2"
  }

Answer 1

正如我在评论中提到的，实现实时功能的正确方式是使用sockets。但是，如果你需要以轮询的方式进行操作，你可以编写一个守卫，类似于以下示例：

actions: {
  start() {
    if (this.timer.isRunning) return;

    this.timer.isRunning = true;
    this.syncTimer();

    this.timer.timer = setInterval(() => {
      if (this.timer.time > 0) {
        this.timer.time--;
      } else {
        clearInterval(this.timer.timer);
        this.reset();
      }
    }, 1000);
  },
  // ...
}

希望有用