Utilizing Native View Transitions in Vue Router

---
description: Enforce the use of native view transitions in Vue Router to enhance user experience with smooth and engaging navigation.
globs: ["src/**/*.vue"]
tags: [vue, vue-router, transitions, user-experience]
priority: 2
version: 1.0.0
---

# Utilizing Native View Transitions in Vue Router

## Context
- Applicable to Vue.js applications using Vue Router for navigation.
- Aims to implement native view transitions to create seamless and engaging user experiences.

## Requirements
- **Check Browser Support**: Ensure the View Transitions API is supported by the user's browser before implementation.
- **Implement Native View Transitions**: Utilize the `startViewTransition` method to initiate transitions during route changes.
- **Provide Fallbacks**: Implement fallback mechanisms for browsers that do not support the View Transitions API.
- **Optimize Performance**: Monitor and optimize the performance impact of view transitions to maintain application responsiveness.

## Examples

<example>
**Good Example**: Implementing native view transitions with a fallback for unsupported browsers.

<template>
  <RouterView v-if="isViewTransitionSupported" class="view-container" />
  <RouterView v-else v-slot="{ Component }">
    <transition name="fade">
      <component :is="Component" class="view-container" />
    </transition>
  </RouterView>
</template>

<script>
import { ref, onBeforeRouteUpdate } from 'vue';
import { useRouter } from 'vue-router';

export default {
  setup() {
    const isViewTransitionSupported = ref('startViewTransition' in document);
    const router = useRouter();

    onBeforeRouteUpdate((to, from, next) => {
      if (isViewTransitionSupported.value) {
        const transition = document.startViewTransition(() => {
          // Perform DOM updates here
        });
        transition.finished.then(() => {
          // Handle post-transition logic
        });
      } else {
        // Fallback for browsers without View Transitions API
      }
      next();
    });

    return { isViewTransitionSupported };
  },
};
</script>

<style>
.view-container {
  /* Define styles for the view container */
}

.fade-enter-active, .fade-leave-active {
  transition: opacity 0.3s ease;
}

.fade-enter, .fade-leave-to {
  opacity: 0;
}
</style>
</example>

<example type="invalid">
**Bad Example**: Implementing view transitions without checking for browser support, leading to potential errors in unsupported browsers.

<template>
  <RouterView class="view-container" />
</template>

<script>
import { onBeforeRouteUpdate } from 'vue';
import { useRouter } from 'vue-router';

export default {
  setup() {
    const router = useRouter();

    onBeforeRouteUpdate((to, from, next) => {
      const transition = document.startViewTransition(() => {
        // Perform DOM updates here
      });
      transition.finished.then(() => {
        // Handle post-transition logic
      });
      next();
    });
  },
};
</script>

<style>
.view-container {
  /* Define styles for the view container */
}
</style>
</example>