Plugins Directory
Nuxt automatically reads the files in your plugins
directory and loads them at the creation of the Vue application. You can use .server
or .client
suffix in the file name to load a plugin only on the server or client side.
plugins/
directory are auto-registered, so you should not add them to your nuxt.config
separately.Which Files Are Registered
Only files at the top level of the plugins/
directory (or index files within any subdirectories) will be registered as plugins.
For example:
plugins | - myPlugin.ts | - myOtherPlugin | --- supportingFile.ts | --- componentToRegister.vue | --- index.ts
Only myPlugin.ts
and myOtherPlugin/index.ts
would be registered.
Creating Plugins
The only argument passed to a plugin is nuxtApp
.
export default defineNuxtPlugin(nuxtApp => { // Doing something with nuxtApp})
Plugin Registration Order
You can control the order in which plugins are registered by prefixing a number to the file names.
For example:
plugins/ | - 1.myPlugin.ts | - 2.myOtherPlugin.ts
In this example, 2.myOtherPlugin.ts
will be able to access anything that was injected by 1.myPlugin.ts
.
This is useful in situations where you have a plugin that depends on another plugin.
Using Composables Within Plugins
You can use composables within Nuxt plugins:
export default defineNuxtPlugin((NuxtApp) => { const foo = useFoo()})
However, keep in mind there are some limitations and differences:
If a composable depends on another plugin registered later, it might not work.
Reason: Plugins are called in order sequentially and before everything else. You might use a composable that depends on another plugin which has not been called yet.
If a composable depends on the Vue.js lifecycle, it won't work.
Reason: Normally, Vue.js composables are bound to the current component instance while plugins are only bound to nuxtApp
instance.
Automatically Providing Helpers
If you would like to provide a helper on the NuxtApp
instance, return it from the plugin under a provide
key. For example:
export default defineNuxtPlugin(() => { return { provide: { hello: (msg: string) => `Hello ${msg}!` } }})
In another file you can use this:
<template> <div> {{ $hello('world') }} </div></template><script setup lang="ts">// alternatively, you can also use it hereconst { $hello } = useNuxtApp()</script>
Typing Plugins
If you return your helpers from the plugin, they will be typed automatically; you'll find them typed for the return of useNuxtApp()
and within your templates.
useNuxtApp()
to get the typed version. But in general, this should be avoided unless you are certain of the plugins' order.Advanced
For advanced use-cases, you can declare the type of injected properties like this:
declare module '#app' { interface NuxtApp { $hello (msg: string): string }}declare module '@vue/runtime-core' { interface ComponentCustomProperties { $hello (msg: string): string }}export { }
Vue Plugins
If you want to use Vue plugins, like vue-gtag to add Google Analytics tags, you can use a Nuxt plugin to do so.
There is an Open RFC to make this even easier! See nuxt/nuxt#17143
First, install the plugin you want.
yarn add --dev vue-gtag-next
Then create a plugin file plugins/vue-gtag.client.js
.
import VueGtag from 'vue-gtag-next'export default defineNuxtPlugin((nuxtApp) => { nuxtApp.vueApp.use(VueGtag, { property: { id: 'GA_MEASUREMENT_ID' } })})
Vue Directives
Similarly, you can register a custom Vue directive in a plugin. For example, in plugins/directive.ts
:
export default defineNuxtPlugin((nuxtApp) => { nuxtApp.vueApp.directive('focus', { mounted (el) { el.focus() }, getSSRProps (binding, vnode) { // you can provide SSR-specific props here return {} } })})