Detailed explanation of the combined API in Vue3: a better way to write components

Detailed explanation of the combined API in Vue3: a better way to write components

The new combined API is introduced in Vue3, which helps to better organize and write components. This article will introduce the use and advantages of these APIs in detail.

1. setup

In Vue3, a new setup function is added to the component options, which is a function that is executed before the component is instantiated. In the setup function, you can do some data preparation work, and you can also return some data or functions for template use. In the setup function, we can use two parameters: props and context.

1.1 props

Props are external data of components and can be used in templates. Using props in the setup function, you can perform responsive processing through reactive or ref.

1.2 context

Context is a new context object that contains some information that component instances may need, such as attrs and emit. Detailed introduction below.

2. reactive

The reactive function is a new data responsive processing function in Vue3, which can turn an object into a responsive object. The return value of the reactive function is a responsive object. When the data in the responsive object changes, the related components will be re-rendered.

3. ref

The ref function is also a new data responsive processing function in Vue3. It can turn a basic type of data into responsive data. The return value of the ref function is an object that contains the value attribute. When the value of the value attribute changes, the related component will be re-rendered.

4. computed

The computed function is a new calculated property function in Vue3. It can return the value of a calculated property through a function. When the data that the calculated property depends on occurs When changes occur, related components will be re-rendered.

5. watch

The watch function is a new observation data change function in Vue3. It can observe a data and execute a function when the data changes. The return value of the watch function is a function that can be used to stop observing.

6. provide and inject

provide and inject are new dependency injection functions in Vue3. They allow us to provide a data or function in the parent component and in the child component. Use the inject function in the component to receive.

7. Life cycle

The life cycle in Vue3 has undergone some changes compared to Vue2. It no longer exists as a function, but as a separate API. . In the combined API, we can handle the life cycle of components through onBeforeMount, onMounted, onBeforeUpdate, onUpdated, onBeforeUnmount, onUnmounted, onErrorCaptured and other APIs.

Summary

The combined API is a new component writing method in Vue3, which allows us to better organize and write components. In the combined API, we can use the setup function to process external data and return some data or functions to templates. We can also use reactive, ref, computed, watch and other functions to process responsive changes in data to achieve better results. component effect.

It is recommended that readers can understand and practice with specific examples when studying.

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