VueJS - Vue 3 Composition API: Lifecycle

Using Lifecycle Hooks in the Composition API

The Composition API in Vue 3 provides a set of lifecycle hooks that allow you to perform actions at specific stages of a component's lifecycle. This guide explores how to use these lifecycle hooks effectively in your Vue 3 applications.

Basic Lifecycle Hooks

Here is how to use the basic lifecycle hooks in the Composition API:

// MyComponent.vue



                

Advanced Lifecycle Hooks

Vue 3 provides additional lifecycle hooks for more advanced scenarios:

• onBeforeMount: Called before the component is mounted.
• onBeforeUpdate: Called before the component is updated.
• onBeforeUnmount: Called before the component is unmounted.
• onRenderTracked: Called when a reactive dependency is tracked during rendering.
• onRenderTriggered: Called when a reactive dependency triggers a re-render.

// MyComponent.vue



                

Using Lifecycle Hooks in Custom Hooks

Lifecycle hooks can be used within custom hooks to encapsulate reusable lifecycle logic:

// useCounter.js
import { ref, onMounted, onUnmounted } from 'vue';

export function useCounter() {
  const count = ref(0);
  const increment = () => {
    count.value++;
  };

  onMounted(() => {
    console.log('Counter mounted');
  });

  onUnmounted(() => {
    console.log('Counter unmounted');
  });

  return {
    count,
    increment
  };
}

// MyComponent.vue



                

Best Practices

Follow these best practices when using lifecycle hooks with the Composition API:

• Keep Lifecycle Hooks Simple: Keep the logic in lifecycle hooks simple to avoid complexity and maintain readability.
• Encapsulate Reusable Logic: Use custom hooks to encapsulate reusable lifecycle logic and promote code reuse.
• Test Thoroughly: Test your components thoroughly to ensure that lifecycle hooks behave as expected in different scenarios.
• Document Your Hooks: Document the lifecycle hooks used in your custom hooks to ensure clarity and ease of use.

Summary

This guide provided an overview of using lifecycle hooks in the Vue 3 Composition API. By leveraging these hooks, you can perform actions at specific stages of a component's lifecycle, improving the maintainability and flexibility of your Vue 3 applications.