Detailed explanation of the keep-alive function in Vue3: Optimizing application performance

With the continuous development of front-end applications, users have higher and higher requirements for application performance. Therefore, developers not only need to consider the functionality and interactive experience of the application, but also need to optimize the performance of the application to the best state. In Vue3, the keep-alive function has become an important means to optimize application performance. This article will explain the keep-alive function in Vue3 in detail.

1. What is the keep-alive function

In Vue3, keep-alive is an abstract component used to cache component instances. When a component is wrapped in a keep-alive tag after being rendered for the first time, the component instance will be cached and read directly from the cache when it needs to be re-rendered, avoiding the frequent process of destroying and re-creating component instances. .

2. Use of keep-alive

In Vue3, using the keep-alive function is very simple. You only need to put the components that need to be cached in the keep-alive tag, as follows Display:

<template>
    <div>
        <keep-alive>
            <router-view />
        </keep-alive>
    </div>
</template>

Among them, router-view is an abstract component of Vue-router, used to dynamically render matching components based on routing.

It should be noted that keep-alive will only cache the instance of the component. The state and data within the component will not be cached. Therefore, when the component is cached and activated, the corresponding life cycle hook function will be executed. , such as activated and deactivated.

3. Special attributes of keep-alive

In Vue3, the keep-alive function has two special attributes, namely include and exclude. They are used to configure components that need to be cached and those that do not.

1. include

The include attribute is used to configure the component that needs to be cached. It can be the name of the component or an instance of the component, as shown below:

<template>
    <div>
        <keep-alive :include="['CompA', 'CompB']">
            <router-view />
        </keep-alive>
    </div>
</template>

In the above example, only component instances named CompA and CompB will be cached.

2. exclude

The exclude attribute is used to configure components that do not require caching. It can be the name of the component or an instance of the component, as shown below:

<template>
    <div>
        <keep-alive :exclude="['CompC', 'CompD']">
            <router-view />
        </keep-alive>
    </div>
</template>

In the above example, component instances named CompC and CompD will not be cached.

4. Use scenarios of keep-alive

The keep-alive function can play a better role in the following scenarios:

1. Caching is required during routing switching Route pages to avoid frequent page re-rendering.
2. Components contain complex calculations and data request logic. Caching component instances can avoid repeated execution of these calculations and requests.
3. In scenarios such as TAB pages that display a lot of content, the cache component can avoid the lag problem when frequently switching TAB pages.

5. Summary

The keep-alive function is an important means to optimize application performance in Vue3. By caching component instances, you can avoid frequent destruction and re-creation of component instances. process to optimize application performance and user experience. When using the keep-alive function, you need to note that updates to the state and data within the component will not be cached, and the life cycle hook function will be triggered when the component is cached and activated. When the include and exclude attributes are used properly, the keep-alive function can achieve better optimization results.

The above is the detailed content of Detailed explanation of the keep-alive function in Vue3: Optimizing application performance. For more information, please follow other related articles on the PHP Chinese website!