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How to use vue keep-alive to request data

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May 29, 2018 pm 02:12 PM

keep-alivevuedata

This time I will show you how to use vue keep-alive to request data, and what are the precautions for using vue keep-alive to request data. The following is a practical case, let's take a look.

index page: home page brand entrance

list page: product list page

product page: product details page

When entering the list from the index page Refresh the page. There is no need to refresh the page when returning the list from the product page, so the list uses the keep-alive attribute and keepAlive is set to true. However, a problem was discovered during the development process. When returning from the product page to the list, the list page is not correct. brand list instead of the brand list from a previous click. Since everyone encounters different problems regarding incorrect keep-alive request data, here is my solution. Hope this can give you an idea.

Solution

Many people will change keep-alive by modifying keepAlive. After I tried it, it still didn’t work, so I changed my mind.

Execution sequence of hook functions

Do not use keep-alive

beforeRouteEnter --> created --> mounted --> ; destroyed

Use keep-alive

beforeRouteEnter --> created --> mounted --> activated --> deactivated

Literacy first, many people and I don’t know the above knowledge. In the keep-alive page, you can get the parameters of this.$route.params in activated

Avoid setting keepAlive. When the product returns, the data is incorrect. When the page enters the list, it is in a cached state. Then it is judged whether to execute the function in activated by whether it is entered from the index.

list.vue

   beforeRouteEnter(to, from, next) {
   //判断从index页面进入，将list的isBack设置为true
   //这样就可以请求数据了
     if (from.name == 'index') {
      to.meta.isBack = true;
     }
     next();
   },
   activated: function () {
     if (this.$route.meta.isBack || this.isFirstEnter) {
      //清理已有商品列表的数据，重新请求数据，如果不清除的话就会有之前的商品缓存，延迟显示最新的商品
      this.proData = [];
      //请求数据
      this.fetchData();
     }
     //重新设置当前路由的isBack
     this.$route.meta.isBack = false;
     //重新设置是否第一次进入
     this.isFirstEnter = false;
   },
   mounted: function () {
    //如果是第一次进入，或者刷新操作的话，也请求数据
     this.isFirstEnter = true;
   },

router.js

const appRouter = {
 mode: "history",
 base: "/m/",
 routes: [
  {
   path: "",
   redirect: "/index"
  },
  {
   path: "/index",
   name: "index",
   component: Index,
   meta: {
    keepAlive: true
   }
  },
    {
   path: "/list",
   name: "list",
   component: List,
   meta: {
    keepAlive: true,
    isBack: false //isback是true的时候请求数据，或者第一次进入的时候请求数据
   }
  },
  {
   path: "/product/:id",
   name: "product",
   component: Product,
   meta: {
    keepAlive: false
   }
  }
  
 ]
};

Vue.use(Router);
export default new Router(appRouter);

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

How to operate vue input input verification letter and number combination and the length is less than 30

How to use seajs Write convention in require

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