【vue】pinia状态持久化

利用watch深度监听

通过监听pinia状态变化来缓存，特点是简单粗暴

import { createApp, watch } from "vue";
import { createPinia } from "pinia";
import App from "./App.vue";
import router from "./router";
const app = createApp(App);
const pinia = createPinia();
app.use(pinia);
// pinia状态持久化
const piniaState = localStorage.getItem("piniaState");
if (piniaState) {
  pinia.state.value = JSON.parse(piniaState);
}
watch(
  pinia.state,
  (state) => {
    // persist the whole state to the local storage whenever it changes
    localStorage.setItem("piniaState", JSON.stringify(state));
  },
  { deep: true }
);
app.use(router);
app.mount("#app");

利用plugins实现

plguins提供了针对每个store的颗粒度操作，我们利用其中的store.$subscribe()和store.$patch就可以做到持久化的作用，再通过options.persist属性设置来进一步控制持久化的开关。

持久化插件函数：

import type { PiniaPluginContext } from "pinia";
declare module "pinia" {
  export interface DefineStoreOptionsBase<S extends StateTree, Store> {
    persist?: boolean;
  }
}
export default function ({ store, options }: PiniaPluginContext) {
  if (!options.persist) return;
  const key = store.$id;
  store.$subscribe((mutation, state) => {
    localStorage.setItem(key, JSON.stringify(state));
  });
  const piniaState = localStorage.getItem(key);
  if (piniaState) {
    store.$patch(JSON.parse(piniaState));
  }
}

在入口文件使用：

import { createApp } from "vue";
import { createPinia } from "pinia";
import myPluginPersistedstate from "@/stores/plugins/persistedstate";
const app = createApp(App);
const pinia = createPinia();
pinia.use(myPluginPersistedstate);
app.use(pinia);

在需要持久化的store中设置persist: true

import { defineStore } from "pinia";
export const useCounterStore = defineStore({
  id: "counter",
  state: () => ({
    counter: 0,
  }),
  persist: true,
});

使用第三方插件

一些现成的第三方插件（建议：pinia-plugin-persistedstate），可以提供更精细化的控制，比如：开启持久化、缓存方式、自定义缓存key等。

参考

• pinia
• pinia-plugin-persistedstate