VueJS - Vue 3 Composition API

Introduction to Vue 3 Composition API

The Composition API in Vue 3 is a powerful feature that enables a more flexible and reusable way to compose component logic. It provides a set of APIs that can be used alongside or as an alternative to the Options API.

Basic Usage of Composition API

The `setup` function is the entry point for using the Composition API in a component. It is called before the component is created and serves as a replacement for the data, computed, methods, and lifecycle hooks options in the Options API.

// MyComponent.vue



                

Reactive State

The `ref` function is used to create a reactive reference to a value. The `reactive` function creates a reactive object:

// MyComponent.vue



                

Computed Properties

The `computed` function is used to create computed properties that automatically update when their dependencies change:

// MyComponent.vue



                

Watchers

The `watch` and `watchEffect` functions are used to perform side effects in response to reactive state changes:

// MyComponent.vue



                

Using Composition API with Options API

The Composition API can be used alongside the Options API in the same component, allowing for a gradual adoption:

// MyComponent.vue



                

Best Practices

Follow these best practices when using the Composition API in Vue 3:

• Group Related Logic: Group related pieces of logic together to make your code more readable and maintainable.
• Use Composables: Extract reusable logic into composable functions to promote code reuse and separation of concerns.
• Minimize Side Effects: Keep side effects to a minimum and use watchers judiciously to avoid unnecessary reactivity.
• Document Your Code: Document your composable functions and components to make it clear how they work and how to use them.
• Test Thoroughly: Test your components and composable functions thoroughly to ensure they work as expected in different scenarios.

Summary

This guide provided an introduction to the Vue 3 Composition API, including basic usage, reactive state, computed properties, watchers, and using the Composition API alongside the Options API. By leveraging the Composition API, you can create more flexible and reusable component logic in your Vue 3 applications.