What is the purpose of keep alive tag in Vuejs explain with example? 080

 What is the purpose of keep alive tag in Vuejs explain with example?

The <keep-alive> tag in Vue.js serves the purpose of caching inactive components to enhance performance and user experience by preventing unnecessary re-renders when switching between them.

How It Works:

1. Wrapping Components: You wrap dynamic components within the <keep-alive> tag to activate caching:

Code snippet

<keep-alive>
  <component :is="currentView"></component>
</keep-alive>

2. Caching Mechanism:

• When a component is first rendered within <keep-alive>, its instance is cached.

• When switching away from it, the instance remains in memory instead of being destroyed.

• When returning to it, Vue reuses the cached instance, avoiding re-creation and re-rendering.

Benefits:

• Performance Optimization: Caching reduces re-renders, improving performance for components that involve:

• Expensive computations

• Data fetching

• DOM manipulations

• Preserving State: Cached components maintain their state, leading to a smoother user experience, especially for:

• Forms with user input

• Components with interactive elements

Example:

Code snippet

<template>
  <keep-alive>
    <component :is="currentTabComponent"></component>
  </keep-alive>
</template>

<script>
export default {
  data() {
    return {
      currentTabComponent: 'Tab1',
    };
  },
  components: {
    Tab1: { /* ... */ },
    Tab2: { /* ... */ },
    Tab3: { /* ... */ },
  },
};
</script>

When to Use <keep-alive>:

• Components that involve expensive computations or data fetching.

• Forms or components that need to preserve user input or state.

• Scenarios where frequent switching between components causes noticeable performance issues.

Considerations:

• Caching can consume more memory, so use it judiciously.

• It might not be suitable for components that change frequently.

• Cached components might not receive updates from shared state or props until they are re-activated.