12 Prompts for Vue.js and Nuxt: Components, Composables, and Routing

Create a Vue 3 Button component with the following requirements:
- Props: variant (primary, secondary, outline), size (sm, md, lg), disabled (boolean)
- Emit a 'click' event
- Use scoped CSS for styling
- Include TypeScript prop validation
- Add a default slot for children

<template>
  <button
    :class="['btn', `btn--${variant}`, `btn--${size}`, { 'btn--disabled': disabled }]"
    :disabled="disabled"
    @click="$emit('click', $event)"
  >
    <slot />
  </button>
</template>

<script setup lang="ts">
withDefaults(defineProps<{
variant?: 'primary'

| 'secondary' | 'outline'
size?: 'sm'

| 'md' | 'lg'
  disabled?: boolean
}>(), {
  variant: 'primary',
  size: 'md',
  disabled: false
})

defineEmits<{
  click: [event: MouseEvent]
}>()
</script>

<style scoped>
.btn { padding: 0.5rem 1rem; border-radius: 4px; }
.btn--primary { background: #42b883; color: white; }
.btn--disabled { opacity: 0.5; pointer-events: none; }
</style>

Write a Vue 3 composable called 'useApiFetch' that:
- Accepts a URL string and optional options object (method, headers, body)
- Returns reactive refs: data, error, loading
- Uses the fetch API with async/await
- Automatically aborts previous requests when called again
- Provides a 'refresh' function to re-fetch manually

import { ref } from 'vue'

export function useApiFetch<T = unknown>(url: string, options?: RequestInit) {
  const data = ref<T | null>(null)
  const error = ref<string | null>(null)
  const loading = ref(false)
  let abortController: AbortController | null = null

  async function execute() {
    abortController?.abort()
    abortController = new AbortController()
    loading.value = true
    error.value = null

    try {
      const response = await fetch(url, { ...options, signal: abortController.signal })
      if (!response.ok) throw new Error(`HTTP ${response.status}`)
      data.value = await response.json()
    } catch (e) {
      if (e instanceof Error && e.name !== 'AbortError') {
        error.value = e.message
      }
    } finally {
      loading.value = false
    }
  }

  execute()

  return { data, error, loading, refresh: execute }
}

Create a Pinia store for authentication with:
- State: user (object or null), token (string or null)
- Actions: login(email, password), logout(), checkAuth()
- Use localStorage for token persistence
- Include a getter 'isAuthenticated' that returns boolean
- Mock the API call in login (simulate with setTimeout)

import { defineStore } from 'pinia'
import { ref, computed } from 'vue'

export const useAuthStore = defineStore('auth', () => {
  const user = ref<{ email: string; name: string } | null>(null)
  const token = ref<string | null>(localStorage.getItem('auth_token'))

  const isAuthenticated = computed(() => !!token.value)

  async function login(email: string, password: string) {
    // Simulate API call
    await new Promise(resolve => setTimeout(resolve, 1000))
    if (email === 'test@example.com' && password === 'password') {
      const mockToken = 'mock-jwt-token-' + Date.now()
      token.value = mockToken
      user.value = { email, name: 'Test User' }
      localStorage.setItem('auth_token', mockToken)
    } else {
      throw new Error('Invalid credentials')
    }
  }

  function logout() {
    user.value = null
    token.value = null
    localStorage.removeItem('auth_token')
  }

  function checkAuth() {
    if (token.value) {
      // Optionally validate token with backend
      user.value = { email: 'user@example.com', name: 'User' }
    }
  }

  return { user, token, isAuthenticated, login, logout, checkAuth }
})

Create a Nuxt 3 default layout with:
- A responsive navigation bar using Tailwind CSS classes
- Dynamic links: 'Home', 'About' for all users, 'Dashboard' for authenticated users
- Use the useAuthStore composable to check authentication
- Include a slot for page content
- Add a mobile hamburger menu toggle

<template>
  <div>
    <nav class="bg-gray-800 text-white p-4">
      <div class="container mx-auto flex items-center justify-between">
        <div class="flex space-x-4">
          <NuxtLink to="/" class="hover:text-gray-300">Home</NuxtLink>
          <NuxtLink to="/about" class="hover:text-gray-300">About</NuxtLink>
          <NuxtLink v-if="auth.isAuthenticated" to="/dashboard" class="hover:text-gray-300">Dashboard</NuxtLink>
        </div>
        <button @click="menuOpen = !menuOpen" class="md:hidden">☰</button>
      </div>
      <div v-if="menuOpen" class="md:hidden mt-2 space-y-2">
        <NuxtLink to="/" class="block px-4 py-2 hover:bg-gray-700">Home</NuxtLink>
        <NuxtLink to="/about" class="block px-4 py-2 hover:bg-gray-700">About</NuxtLink>
        <NuxtLink v-if="auth.isAuthenticated" to="/dashboard" class="block px-4 py-2 hover:bg-gray-700">Dashboard</NuxtLink>
      </div>
    </nav>
    <main class="container mx-auto p-4">
      <slot />
    </main>
  </div>
</template>

<script setup lang="ts">
const auth = useAuthStore()
const menuOpen = ref(false)
</script>

Create a Vue Router configuration for a Vue 3 app with:
- Lazy-loaded routes: Home, About, Dashboard (requires auth), Login
- A beforeEach navigation guard that checks if the route requires auth
- If not authenticated, redirect to /login with a redirect query parameter
- After login, redirect back to the original route
- Use createRouter with history mode

import { createRouter, createWebHistory } from 'vue-router'
import { useAuthStore } from '@/stores/auth'

const routes = [
  { path: '/', name: 'Home', component: () => import('@/views/Home.vue') },
  { path: '/about', name: 'About', component: () => import('@/views/About.vue') },
  { path: '/login', name: 'Login', component: () => import('@/views/Login.vue') },
  {
    path: '/dashboard',
    name: 'Dashboard',
    component: () => import('@/views/Dashboard.vue'),
    meta: { requiresAuth: true }
  }
]

const router = createRouter({
  history: createWebHistory(),
  routes
})

router.beforeEach((to, from, next) => {
  const auth = useAuthStore()
  if (to.meta.requiresAuth && !auth.isAuthenticated) {
    next({ name: 'Login', query: { redirect: to.fullPath } })
  } else {
    next()
  }
})

export default router

Create a Vue 3 login form component with:
- Reactive form state using refs
- Validation rules: email must be valid format, password minimum 6 characters
- Display inline error messages for each field
- Submit handler that calls the auth store's login action
- Show loading state during submission
- Disable submit button when form is invalid or loading

<template>
  <form @submit.prevent="handleSubmit" class="max-w-md mx-auto p-4 space-y-4">
    <div>
      <label for="email">Email</label>
      <input v-model="email" type="email" id="email" class="border p-2 w-full" />
      <p v-if="emailError" class="text-red-500 text-sm">{{ emailError }}</p>
    </div>
    <div>
      <label for="password">Password</label>
      <input v-model="password" type="password" id="password" class="border p-2 w-full" />
      <p v-if="passwordError" class="text-red-500 text-sm">{{ passwordError }}</p>
    </div>
    <button type="submit" :disabled="!isValid || loading" class="bg-blue-500 text-white px-4 py-2 rounded disabled:opacity-50">
      {{ loading ? 'Logging in...' : 'Login' }}
    </button>
  </form>
</template>

<script setup lang="ts">
import { ref, computed } from 'vue'
import { useAuthStore } from '@/stores/auth'

const auth = useAuthStore()
const email = ref('')
const password = ref('')
const loading = ref(false)

const emailError = computed(() => {
  if (!email.value) return 'Email is required'
  if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email.value)) return 'Invalid email format'
  return ''
})

const passwordError = computed(() => {
  if (!password.value) return 'Password is required'
  if (password.value.length < 6) return 'Password must be at least 6 characters'
  return ''
})

const isValid = computed(() => !emailError.value && !passwordError.value && email.value && password.value)

async function handleSubmit() {
  if (!isValid.value) return
  loading.value = true
  try {
    await auth.login(email.value, password.value)
  } catch (e) {
    alert('Login failed')
  } finally {
    loading.value = false
  }
}
</script>

Create a Nuxt 3 server API route at /api/register that:
- Accepts POST requests with JSON body: email, password, name
- Validates input using Zod (email format, password min 6 chars, name min 2 chars)
- Returns 400 with error messages if validation fails
- Returns 201 with success message if valid
- Simulate saving to a database (just log the data)

import { z } from 'zod'

export default defineEventHandler(async (event) => {
  const body = await readBody(event)

  const schema = z.object({
    email: z.string().email('Invalid email'),
    password: z.string().min(6, 'Password must be at least 6 characters'),
    name: z.string().min(2, 'Name must be at least 2 characters')
  })

  const result = schema.safeParse(body)
  if (!result.success) {
    throw createError({
      statusCode: 400,
      statusMessage: result.error.errors.map(e => e.message).join(', ')
    })
  }

  // Simulate database save
  console.log('User registered:', result.data)

  return { success: true, message: 'User registered successfully' }
})

Write a Vue 3 composable called 'useDebouncedSearch' that:
- Accepts a search function that returns a promise
- Returns reactive refs: query (string), results (array), loading (boolean)
- Debounces the search by 300ms using setTimeout
- Cancels previous pending search requests
- Automatically triggers search when query changes

import { ref, watch } from 'vue'

export function useDebouncedSearch<T>(
  searchFn: (query: string) => Promise<T[]>,
  delay = 300
) {
  const query = ref('')
  const results = ref<T[]>([])
  const loading = ref(false)
  let timer: ReturnType<typeof setTimeout> | null = null
  let abortController: AbortController | null = null

  watch(query, (newQuery) => {
    if (timer) clearTimeout(timer)
    timer = setTimeout(async () => {
      if (!newQuery.trim()) {
        results.value = []
        return
      }
      loading.value = true
      abortController?.abort()
      abortController = new AbortController()
      try {
        const data = await searchFn(newQuery)
        results.value = data
      } catch {
        // Handle error silently
      } finally {
        loading.value = false
      }
    }, delay)
  })

  return { query, results, loading }
}

Create a Vue 3 custom directive called 'v-click-outside' that:
- Accepts a callback function as value
- Attaches a click event listener to the document
- Detects if the click target is outside the element
- Calls the callback when outside click is detected
- Cleans up the event listener on unmount
- Works with the composition API style

import { Directive, DirectiveBinding } from 'vue'

export const vClickOutside: Directive = {
  mounted(el: HTMLElement, binding: DirectiveBinding) {
    const handler = (event: MouseEvent) => {
      if (!el.contains(event.target as Node)) {
        binding.value(event)
      }
    }
    document.addEventListener('click', handler)
    el._clickOutsideHandler = handler
  },
  unmounted(el: HTMLElement) {
    document.removeEventListener('click', el._clickOutsideHandler)
  }
}

Create a Nuxt 3 route middleware called 'auth' that:
- Checks if the user is authenticated via useAuthStore
- If not authenticated, redirects to /login with a query parameter ?redirect=currentPath
- If authenticated, allows navigation
- Runs on the client side only (use nuxtApp.ssrContext check)

export default defineNuxtRouteMiddleware((to, from) => {
  const auth = useAuthStore()

  // Only run on client side
  if (process.client && !auth.isAuthenticated) {
    return navigateTo({
      path: '/login',
      query: { redirect: to.fullPath }
    })
  }
})

Write a Vue 3 composable called 'useLocalStorage' that:
- Accepts a key (string) and default value
- Returns a reactive ref that syncs with localStorage
- Watches for changes and updates localStorage automatically
- Handles JSON serialization/deserialization
- Handles errors gracefully (e.g., localStorage full)

import { ref, watch } from 'vue'

export function useLocalStorage<T>(key: string, defaultValue: T) {
  let initialValue: T
  try {
    const stored = localStorage.getItem(key)
    initialValue = stored ? JSON.parse(stored) : defaultValue
  } catch {
    initialValue = defaultValue
  }

  const data = ref<T>(initialValue)

  watch(data, (newValue) => {
    try {
      localStorage.setItem(key, JSON.stringify(newValue))
    } catch (e) {
      console.error('Failed to save to localStorage', e)
    }
  }, { deep: true })

  return data
}

Create a Vue 3 component called 'FadeTransition' that:
- Uses Vue's built-in <Transition> component
- Provides a fade animation (opacity 0 to 1) over 300ms
- Accepts a 'show' prop to control visibility
- Has a default slot for content
- Supports custom duration via prop

<template>
  <Transition name="fade">
    <div v-if="show">
      <slot />
    </div>
  </Transition>
</template>

<script setup lang="ts">
withDefaults(defineProps<{
  show: boolean
  duration?: number
}>(), {
  duration: 300
})
</script>

<style scoped>
.fade-enter-active,
.fade-leave-active {
  transition: opacity v-bind(duration + 'ms') ease;
}
.fade-enter-from,
.fade-leave-to {
  opacity: 0;
}
</style>