Detailed explanation of how to use keep-alive in vue

This time I will bring you a detailed explanation of how to use keep-alive in Vue. What are the precautions for using keep-alive in Vue? Here are practical cases, let’s take a look.

1. The role and benefits of keep-alive

In e-commerce related projects, when we enter the list page for the first time I need to request data. When I enter the details page from the list page, I need to request the data even if the details page is not cached, and then return to the list page. At this time, we use keep-alive to cache the component to prevent secondary rendering, which will save a lot of money. performance.

2. Basic usage of keep-alive

In app.vue

<!-- 缓存所有的页面 -->
<keep-alive>
 <router-view v-if="$route.meta.keep_alive"></router-view>
</keep-alive>
<router-view v-if="!$route.meta.keep_alive"></router-view>

The component content that needs to be cached is directly Add in the router:

meta: {
 keepAlive: true // true 表示需要使用缓存 false表示不需要被缓存
 }

3.keep-alive life cycle

When keep-alive is introduced, the page first Upon entry, the trigger sequence of the hook is created-> mounted-> activated, and deactivated is triggered when exiting. When entering again (forward or backward), only activated is triggered.

Let’s take a look at the usage problems and solutions of keep-alive in vue

Problem description

In business development, there will be scenarios where routing jumps but data needs to be retained when returning; vue provides keep-alive to handle

Solution

Return The dom does not allow it to be refreshed, and wraps a layer outside the vue-view. When keep-alive is introduced, the page is entered for the first time, the trigger sequence of the hook is created-> mounted-> activated, and deactivated is triggered when exiting. When entering again (forward or backward), only activated is triggered.

Event mounting methods, etc., which are only executed once are placed in mounted; methods that are executed each time the component is entered are placed in activated;
Whether to wrap keep-alive can be configured through parameters;

<keep-alive>
  <router-view v-if="$route.meta.keepAlive" style="min-height:100%"></router-view>
</keep-alive>
<router-view v-if="!$route.meta.keepAlive" style="min-height:100%"></router-view>
//不需要刷新的路由配置里面配置 meta: {keepAlive: true}, 这个路由则显示在上面标签；
//需要刷新的路由配置里面配置 meta: {keepAlive: false}, 这个路由则显示在下面标签；

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!

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