Naive UI Loading Bar Component

A kind of good placebo for anxiety. Shows loading progress for async operations.

When to Use

Use this component when:

• Route transitions: Show loading during page navigation
• API requests: Indicate pending async operations
• File operations: Display progress for file uploads/downloads
• Long processes: Provide feedback during lengthy operations

When to Invoke

Invoke this skill when:

• User needs to implement loading indicators
• User wants to show loading progress for async operations
• User needs route transition loading feedback
• User wants to customize loading bar appearance
• User asks about loading state management

Features

• Global Provider: Wrap app with LoadingBarProvider
• Injection API: Use useLoadingBar hook in components
• Multiple States: Support start, finish, and error states
• Custom Styling: Configure loading bar style
• Local Mounting: Mount to specific container

API Reference

LoadingBarProvider Props

Name	Type	Default	Description	Version
container-class	string	undefined	Class of the loading bar container.	2.33.4
container-style	string | object	undefined	Style of the loading bar container.	2.33.4
loading-bar-style	{ loading?: string | object, error?: string | object }	undefined	Style of the loading bar.
to	string | HTMLElement | false	undefined	Mount target of loading bar.	2.33.4

loadingBar Injection Methods

Name	Type	Description
error	() => void	Callback function for loading bar error.
finish	() => void	The callback function when the loading bar finishes loading.
start	() => void	Callback function for loading bar to start loading.

Basic Usage

Setup Provider

<!-- App.vue -->
<template>
  <n-loading-bar-provider>
    <router-view />
  </n-loading-bar-provider>
</template>

Using in Components

<template>
  <n-space>
    <n-button @click="handleStart">
      Start
    </n-button>
    <n-button :disabled="loading" @click="handleFinish">
      Finish
    </n-button>
    <n-button @click="handleError">
      Error
    </n-button>
  </n-space>
</template>

<script setup>
import { ref } from 'vue'
import { useLoadingBar } from 'naive-ui'

const loadingBar = useLoadingBar()
const loading = ref(false)

const handleStart = () => {
  loading.value = true
  loadingBar.start()
}

const handleFinish = () => {
  loading.value = false
  loadingBar.finish()
}

const handleError = () => {
  loading.value = false
  loadingBar.error()
}
</script>

Common Patterns

Local Loading Bar

<template>
  <n-loading-bar-provider
    :to="loadingBarTargetRef"
    container-style="position: absolute;"
  >
    <div
      ref="loadingBarTargetRef"
      style="
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        border-radius: var(--n-border-radius);
        overflow: hidden;
        pointer-events: none;
      "
    />
    <Content />
  </n-loading-bar-provider>
</template>

API Request Loading

<template>
  <n-button @click="fetchData" :loading="loading">
    Fetch Data
  </n-button>
</template>

<script setup>
import { ref } from 'vue'
import { useLoadingBar } from 'naive-ui'

const loadingBar = useLoadingBar()
const loading = ref(false)

const fetchData = async () => {
  loadingBar.start()
  loading.value = true
  
  try {
    const response = await fetch('/api/data')
    const data = await response.json()
    loadingBar.finish()
  } catch (error) {
    loadingBar.error()
  } finally {
    loading.value = false
  }
}
</script>

Route Transition Loading

<!-- router/index.js -->
import { createRouter, createWebHistory } from 'vue-router'

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

export default router

<!-- App.vue -->
<template>
  <n-loading-bar-provider>
    <router-view />
  </n-loading-bar-provider>
</template>

<script setup>
import { useLoadingBar } from 'naive-ui'
import { useRouter } from 'vue-router'

const loadingBar = useLoadingBar()
const router = useRouter()

router.beforeEach(() => {
  loadingBar.start()
})

router.afterEach(() => {
  loadingBar.finish()
})

router.onError(() => {
  loadingBar.error()
})
</script>

Custom Loading Bar Style

<template>
  <n-loading-bar-provider
    :loading-bar-style="{
      loading: {
        background: '#18a058'
      },
      error: {
        background: '#d03050'
      }
    }"
  >
    <Content />
  </n-loading-bar-provider>
</template>

Best Practices

1. Wrap at app root: Place n-loading-bar-provider at the top level of your app

2. Use with router: Combine with router guards for automatic route transition feedback

3. Handle errors: Always call error() when operations fail

4. Don't forget finish: Ensure finish() is called after operations complete

5. Local vs Global: Use local loading bar for component-specific operations

6. Combine with other feedback: Use alongside loading spinners for better UX