keep-alive is a built-in component of Vue that allows included components to retain state or avoid re-rendering. This article mainly introduces Vue's designated component cache. Friends who need it can refer to
keep-alive introduction
keep-alive is Vue A built-in component that enables the contained component to retain state or avoid re-rendering.
Usage is also very simple:
<keep-alive> <component> <!-- 该组件将被缓存! --> </component> </keep-alive>
props
include - string or regular expression , only matching components will be cached
exclude - string or regular expression, any matching components will not be cached
// 组件 a export default { name: 'a', data () { return {} } } <keep-alive include="a"> <component> <!-- name 为 a 的组件将被缓存! --> </component> </keep-alive>可以保留它的状态或避免重新渲染 <keep-alive exclude="a"> <component> <!-- 除了 name 为 a 的组件都将被缓存! --> </component> </keep-alive>可以保留它的状态或避免重新渲染 <keep-alive include="test-keep-alive"> <!-- 将缓存name为test-keep-alive的组件 --> <component></component> </keep-alive> <keep-alive include="a,b"> <!-- 将缓存name为a或者b的组件,结合动态组件使用 --> <component :is="view"></component> </keep-alive> <!-- 使用正则表达式,需使用v-bind --> <keep-alive :include="/a|b/"> <component :is="view"></component> </keep-alive> <!-- 动态判断 --> <keep-alive :include="includedComponents"> <router-view></router-view> </keep-alive> <keep-alive exclude="test-keep-alive"> <!-- 将不缓存name为test-keep-alive的组件 --> <component></component> </keep-alive>
Meet vue-router
router-view is also a component. If it is directly wrapped in keep-alive, all view components matching the path will be cached:
<keep-alive> <router-view> <!-- 所有路径匹配到的视图组件都会被缓存! --> </router-view> </keep-alive>
However, the product always needs to change its requirements, and there is no way to stop it...
Problem
What should I do if I only want a certain component in router-view to be cached?
Use include/exclude
Add the router.meta attribute
Use include/exclude
// 组件 a export default { name: 'a', data () { return {} } } <keep-alive include="a"> <router-view> <!-- 只有路径匹配到的视图 a 组件会被缓存! --> </router-view> </keep-alive>
exclude The example is similar.
Disadvantages: You need to know the name of the component, which is not a good choice when the project is complex
Add the router.meta attribute
// routes 配置 export default [ { path: '/', name: 'home', component: Home, meta: { keepAlive: true // 需要被缓存 } }, { path: '/:id', name: 'edit', component: Edit, meta: { keepAlive: false // 不需要被缓存 } } ] <keep-alive> <router-view v-if="$route.meta.keepAlive"> <!-- 这里是会被缓存的视图组件,比如 Home! --> </router-view> </keep-alive> <router-view v-if="!$route.meta.keepAlive"> <!-- 这里是不被缓存的视图组件,比如 Edit! --> </router-view>
Advantages: No need to enumerate the name of the component that needs to be cached
[Salt] Use router.meta to expand
Suppose there are 3 routes: A, B, C.
Requirements:
Default display A
B jumps to A, A does not refresh
C jumps to A, A refreshes
Implementation method
In A Set the meta attribute in the route:
{ path: '/', name: 'A', component: A, meta: { keepAlive: true // 需要被缓存 } }
Set beforeRouteLeave in the B component:
export default { data() { return {}; }, methods: {}, beforeRouteLeave(to, from, next) { // 设置下一个路由的 meta to.meta.keepAlive = true; // 让 A 缓存,即不刷新 next(); } };
Set beforeRouteLeave in the C component:
export default { data() { return {}; }, methods: {}, beforeRouteLeave(to, from, next) { // 设置下一个路由的 meta to.meta.keepAlive = false; // 让 A 不缓存,即刷新 next(); } };
In this way, B can return to A, A will not refresh; and C will refresh when returning to A.
The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.
Related articles:
Ajax progress bar download implementation sample code based on Blod
Use Promise to solve multiple asynchronous Ajax Code nesting problem caused by request
Ajax passing JSON instance code
The above is the detailed content of Detailed explanation of vue specified component cache instance. For more information, please follow other related articles on the PHP Chinese website!