## Introduction If you've ever built web applications that involve **forms** , **real-time updates** , or **complex data interactions**, you know the struggle can be real. Traditionally, these features often required setting up separate `API` endpoints and managing intricate client-side state. Next.js 14 Server Actions come to the rescue! They provide a smooth solution, allowing you to execute server-side logic directly from your React components, just like calling a regular function. ## What are Server Actions? Server Actions provide a way to associate server-side functions with your React components. Think of them as directly callable API routes that live within your frontend code. This tight integration simplifies data management and leads to more responsive, snappier applications. Let's explore how Server Actions can supercharge your development workflow and make your apps feel more responsive and interactive. ## Setup Prerequisites: Node.js v18 or Bun ### 1. Create a New Next.js App Learn more about options at [NextJs](https://nextjs.org/docs/getting-started/installation) ```bash npx create-next-app@latest server-actions ``` > Select the recommend - App router, tailwindcss ### 2. Styling We use tailwindcss it's already setup if you select yes while creating NextJs application. We also use [Shadcn ui](https://ui.shadcn.com/docs/installation/next) along with tailwindcss. Shadcn is a collection of re-usable components. ```bash npx shadcn-ui@latest init ``` These are the components we well be using in this demo. ```bash npx shadcn-ui@latest add avatar npx shadcn-ui@latest add button npx shadcn-ui@latest add card npx shadcn-ui@latest add dialog npx shadcn-ui@latest add input npx shadcn-ui@latest add label npx shadcn-ui@latest add switch ``` ### 3. Database, Storage, and Authentication **Supabase:** For the database and storage, we will use [Supabase](https://supabase.com/). It is an open source Firebase alternative. ```bash npm install @supabase/supabase-js ``` - Create a account on supabase it is free. - Create a new Project. Setup project on supabase

- Create a new table. You can use the table editor or sql editor. Create todo table on supabase

- Make sure to add api keys from supabase to .env.local ```.env # .env.local SUPABASE_URL=_Project_URL SUPABASE_SERVICE_ROLE_KEY=_SUPABASE_SERVICE_ROLE_KEY ``` **Auth.js:** For authentication we will use [AuthJs](https://authjs.dev/) . It is updated version of [NextAuth](https://next-auth.js.org/). ``` npm install next-auth@beta @auth/supabase-adapter ``` Follow this guide to setup [supabase](https://authjs.dev/getting-started/adapters/supabase) adapter for auth. > Make sure to Expose the NextAuth schema in Supabase [Api settings](https://app.supabase.com/project/_/settings/api) Create file name `/lib/supabase/private.ts` In this file we will be creating a supabase client and call that clients wherever we need. ```jsx // /lib/supabase/private.ts import { createClient } from '@supabase/supabase-js'; if (!process.env.SUPABASE_URL || !process.env.SUPABASE_SERVICE_ROLE_KEY) { throw new Error('Missing env vars SUPABASE_URL or SUPABASE_SERVICE_ROLE_KEY'); } const privateClient = createClient( process.env.SUPABASE_URL, process.env.SUPABASE_SERVICE_ROLE_KEY, ); export const nextAuthClient = createClient( process.env.SUPABASE_URL, process.env.SUPABASE_SERVICE_ROLE_KEY, { db: { schema: 'next_auth' }, }, ); export default privateClient; ``` ## Start with Authentication ### 1.Setup OAuth app **Github** Follow this [github guide](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/creating-an-oauth-app) for creating Oauth ```env CALLBACK_ENV https://example.com/api/auth/callback/github ``` After creating Oauth in github copy `API` keys from github as it required by AuthJs. Along this api key you have to get AUTH_SECRET, which you can generate from this: ```bash npx auth secret ``` Or Visit the [Vercel App](https://generate-secret.vercel.app/32) to generate secret Add all the key to you .env.local. ```.env # .env.local AUTH_SECRET= AUTH_GITHUB_ID= AUTH_GITHUB_SECRET= ``` **Google** [Google OAuth documentation](https://developers.google.com/identity/protocols/oauth2) ```env CALLBACK ENV = https://example.com/api/auth/callback/google ``` ```.env # .env.local AUTH_GOOGLE_ID= AUTH_GOOGLE_SECRET= ``` ### 2.Auth.ts Crate auth.ts in route of your project. ```jsx // app.ts import NextAuth from 'next-auth'; import { SupabaseAdapter } from '@auth/supabase-adapter'; import GitHub from 'next-auth/providers/github'; import Google from "next-auth/providers/google" import type { NextAuthConfig } from 'next-auth'; export const config = { providers: [GitHub,Google], adapter: SupabaseAdapter({ url: process.env.SUPABASE_URL as string, secret: process.env.SUPABASE_SERVICE_ROLE_KEY as string, }) } satisfies NextAuthConfig; export const { handlers, auth } = NextAuth(config); ``` Here we are using supabase adapter and our choice of providers for auth. You can add more providers from [AuthJs Providers](https://authjs.dev/getting-started#official-providers). If you adding more provider make sure to add Oauth API keys in the .env. ### 3.Adding API route create file in `/api/auth/[...nextauth]/route.ts` ``` // /api/auth/[...nextauth]/route.ts import { handlers } from '@/app/auth'; // check your auth.ts route export const { GET, POST } = handlers; ``` Crate a file name as `middleware.ts` Make sure to add this as same level as App or inside src if you use src as your root. ```ts // middleware.ts export { auth as middleware } from '@/app/auth'; export const config = { matcher: [ /* * Match all request paths except for the ones starting with: * - _next/static (static files) * - _next/image (image optimization files) * - favicon.ico (favicon file) * Feel free to modify this pattern to include more paths. */ '/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)', ], }; ``` ### 4.Create Sign In And Sign Out Create signIn and signOut button ```jsx // components/auth-components.tsx 'use client'; import { signIn, signOut } from 'next-auth/react'; import { Button } from './ui/button'; export function SignIn({ provider, ...props }: { provider?: string } & React.ComponentPropsWithRef) { return ( ); } export function SignOut(props: React.ComponentPropsWithRef) { return ( ); } ``` ### 5.Create Navbar Create navbar where we will show Sign In button. Inside components create file `Navbar.tsx`. ```jsx // Navbar.tsx import Link from 'next/link'; import { Button } from '@/components/ui/button'; import { SignIn, SignOut } from './auth-components'; import { auth } from '@/app/auth'; import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar'; export default async function Navbar() { const session = await auth(); return (

); } ``` Now navbar is by default server component, so we can call supabase auth and check if user is authenticated. > I am hopping that if you learning about server actions, you already know the server and client components. > If not then it's good idea to just learn about them from NextJs official tutorial [Learn NextJS](https://nextjs.org/learn/dashboard-app). With session we will conditionally render different button. You can check that now our authentication system is working, we are able to login with github as well google. In development if your Oauth is not redirect back to application add `AUTH_REDIRECT_PROXY_URL` in env. If you find any difficulty or have some error you can react out to [me](/contact) or check my source code. ``` # .env.local AUTH_REDIRECT_PROXY_URL = /api/auth #only add in dev ``` You can check that our user are now stored in supabase as well. ## Building a Todo App with Server Actions Now our first part is done, we will working on todo application. We will learn how to use server actions in CRUD (Create, Read, Update, Delete). ### 1.Todo Homepage Let's create a new page as 'todos/page.tsx' ```jsx // app/todos/page.tsx import AddTodo from './AddForm'; import TodoList from './TodoList'; import { auth } from '@/app/auth'; import { SignIn } from '@/components/auth-components'; export default async function Todo() { const session = await auth(); if (!session?.user) return (

You must login to perform this action.

); return (

); } ``` As this route is protected, we will check if user is authenticated or not with `auth()` ### 2.Add Todo Form Create new file name `AddForm.tsx`. ``` // todos/AddForm.tsx import { SubmitButton } from '@/components/submit-button'; import { Input } from '@/components/ui/input'; import { Label } from '@/components/ui/label'; import { addTodo } from '@/app/actions'; import { User } from 'next-auth'; export default function AddTodo({ user }: { user: User }) { return (

Add Todo

); } ``` This is simple form with `shadcn` Components. We also using one more hook from react-dom named as `useFormStatus`. It helps us to show pending state such as change the button text to `Submitting...` or disabled the button so user do not resubmit the action. You can learn more about that hook in [React docs](https://react.dev/reference/react-dom/hooks/useFormStatus). Create new client component. ``` // components/submit-button.tsx 'use client'; import { useFormStatus } from 'react-dom'; import { Button } from '@/components/ui/button'; export function SubmitButton({ name, className, variant, }: { name: string; className: string; variant: 'link' | 'outline' | 'default' | 'destructive' | 'secondary' | 'ghost' | null | undefined; }) { const { pending } = useFormStatus(); return ( ); } ``` This hook might change in new version of react. ### 3.Create actions.ts Crate a file name `actions.ts` At start of file write `'use server'`. ```ts // app/actions.ts 'use server'; import supabase from '@/lib/supabase/private'; export async function addTodo( email: string, prevState: any, formData: FormData, ) { try { const { data, error } = await supabase.from('todos').upsert({ title: formData.get('title'), email: email, }); if (error) { console.log('Error', error); return { type: 'error', message: 'Database Error: Failed to add todo.', }; } revalidatePath('/todos'); return { type: 'success', message: `${validatedFields.data.title} added successfully.`, resetKey: Date.now().toString(), }; } catch (error: any) { console.log('Error', error.message); return { type: 'error', message: 'Database Error: Failed to add todo.', }; } } ``` This is the server action name `addTodo`. Here we will get the formData and email of current user. With the help of supabase client we will update the database. Depending on the error or success we will send the message back to our component. ### 4.Update the AddForm.tsx We will add this action to our form with the help of `useFormState`. It is new hook in [react-dom](https://react.dev/reference/react-dom/hooks/useFormState). > As per react `useFormState` is a Hook that allows you to update state based on the result of a form action. As of now React is changing this hook. If you are interested check this github [discussion](https://github.com/facebook/react/pull/28491) This means that we will get error message or success message along with boolean to from server action. We will show that message with [react-hot-toast](https://react-hot-toast.com/docs). Install the react hot toast ```bash npm install react-hot-toast ``` In `layout.tsx` ``` // layout.tsx import type { Metadata } from 'next'; import { Inter } from 'next/font/google'; import './globals.css'; import { Toaster } from 'react-hot-toast'; import Navbar from '@/components/Navbar'; const inter = Inter({ subsets: ['latin'] }); export const metadata: Metadata = { title: 'Server Actions by patelvivek.dev', description: 'Learn server actions with patelvivek.dev', }; export default function RootLayout({ children, }: Readonly<{ children: React.ReactNode; }>) { return ( {children} ); } ``` Updated AddFrom.tsx ```jsx // todos/AddForm.tsx 'use client'; import { toast } from 'react-hot-toast'; import { useEffect } from 'react'; import { useFormState } from 'react-dom'; import { SubmitButton } from '@/components/submit-button'; import { Input } from '@/components/ui/input'; import { Label } from '@/components/ui/label'; import { addTodo } from '@/app/actions'; import { User } from 'next-auth'; const initialState = { message: '', errors: null, }; export default function AddTodo({ user }: { user: User }) { const addTodoWithEmail = addTodo.bind(null, user?.email as string); // Here we are bind user email with action. We can get that email in the server action as a argument. const [state, formAction] = useFormState(addTodoWithEmail as any, initialState); useEffect(() => { if (state.type === 'success') { toast.success(state.message); } if (state.type === 'redirect') { toast.success(state.message); } }, [state]); return (

Add Todo

); } ``` ### 5.Add validation Let's add validation in our form. We will using [zod](https://zod.dev/) with TypeScript. Update `action.ts` ``` import { z } from 'zod'; // =============================== addTodo =============================== const addTodoSchema = z.object({ title: z.string().min(3, { message: 'Must be 3 or more characters long' }), }); export async function addTodo(email: string, prevState: any, formData: FormData) { const validatedFields = addTodoSchema.safeParse({ title: formData.get('title'), }); // Return early if the form data is invalid if (!validatedFields.success) { return { type: 'error', errors: validatedFields.error.flatten().fieldErrors, message: 'Missing Fields. Failed to add todo.', }; } // if not email user is not authenticated if (!email) { return { type: 'redirect', message: 'Please Login again!.', }; } try { const { data, error } = await supabase.from('todos').upsert({ title: validatedFields.data.title, email: email, }); if (error) { console.log('Error', error); return { type: 'error', message: 'Database Error: Failed to add todo.', }; } revalidatePath('/todos'); return { type: 'success', message: `${validatedFields.data.title} added successfully.`, resetKey: Date.now().toString(), }; } catch (error: any) { console.log('Error', error.message); return { type: 'error', message: 'Database Error: Failed to add todo.', }; } } ``` After creating schema we will use `safeParse`. This method returns an object containing either the successfully parsed data or a ZodError instance containing detailed information about the validation problems. If we get success is false, we will send errors back to component, where we will show the error to user. ### 6.revalidatePath If you see the above server actions, we used the [revalidatePath](https://nextjs.org/docs/app/api-reference/functions/revalidatePath). By default next caches every routes, so when we add the todo we want to show to added todo back to the user. That means we have to delete the old cache and update the ui. This is what revalidatePath does for us. Learn more about caching in [NextJS](https://nextjs.org/docs/app/building-your-application/caching) ### 7.TodoList now we will show the list pf todos with some actions button. **db.ts** ``` // app/db.ts import supabase from '@/lib/supabase/private'; import { User } from 'next-auth'; export async function getTodos(user: User) { let { data: todos, error } = await supabase .from('todos') .select('*') // Filters .eq('email', user.email); return todos; } ``` This is the function for getting all the todo from database for current user. **TodoList.tsx** ```jsx // TodoList.tsx import { getTodos } from '@/app/db'; import { Card, CardDescription, CardFooter, CardHeader, CardTitle } from '@/components/ui/card'; import EditForm from './EditForm'; import DeleteForm from './DeleteForm'; import ChangeStatus from './ChangeStatus'; import { User } from 'next-auth'; export default async function TodoList({ user }: { user: User }) { let todos = await getTodos(user); // sort todos with id if (todos != null) { todos = todos.sort((a, b) => a.id - b.id); } if (todos?.length === 0) { return

No todos yet! Please add with above form.

; } return (

{todos?.map((todo) => ( {todo.title} Status: {todo.isCompleted ? ' Completed' : ' Not Completed'} ))}

); } ``` We will fetch all the todo and show the every todo in card. ### 8.EditTodo and DeleteTodo Using same concept from AddForm, we will create EditForm and DeleteForm. **EditForm** ``` // EditForm.tsx 'use client'; import { toast } from 'react-hot-toast'; import { useEffect, useState } from 'react'; import { useFormState } from 'react-dom'; import { SubmitButton } from '@/components/submit-button'; import { Input } from '@/components/ui/input'; import { Label } from '@/components/ui/label'; import { Button } from '@/components/ui/button'; import { Switch } from '@/components/ui/switch'; import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle, DialogTrigger, DialogFooter, } from '@/components/ui/dialog'; import { editTodo } from '@/app/actions'; const initialState = { message: '', errors: null, }; export default function EditForm({ todo }: { todo: any }) { const [open, setOpen] = useState(false); const id: number = todo?.id; const editTodoWithId = editTodo.bind(null, id); const [state, formAction] = useFormState(editTodoWithId as any, initialState); useEffect(() => { if (state.type === 'success') { setOpen(false); toast.success(state.message); } }, [state]); return ( ); } ``` **DeleteForm** ``` // DeleteForm.tsx 'use client'; import { toast } from 'react-hot-toast'; import { useEffect } from 'react'; import { useFormState } from 'react-dom'; import { SubmitButton } from '@/components/submit-button'; import { deleteTodo } from '@/app/actions'; const initialState = { message: '', errors: null, }; export default function DeleteForm({ todo }: { todo: any }) { let deleteTodoWithId = deleteTodo.bind(null, todo.id); const [state, formAction] = useFormState(deleteTodoWithId as any, initialState); useEffect(() => { if (state.type === 'success') { toast.success(state.message); } if (state.type === 'error') { toast.error(state.message); } }, [state]); return (

); } ``` **Actions** ``` // actions.ts // =============================== editTodo =============================== const editTodoSchema = z.object({ title: z.string().min(3, { message: 'Must be 3 or more characters long' }), }); export async function editTodo(id: number, prevState: any, formData: FormData) { const isCompleted = formData.get('isCompleted'); const validatedFields = editTodoSchema.safeParse({ title: formData.get('title'), }); let status = false; if (isCompleted === 'on') { status = true; } // Return early if the form data is invalid if (!validatedFields.success) { return { type: 'error', errors: validatedFields.error.flatten().fieldErrors, message: 'Missing Fields. Failed to edit todo.', }; } try { const { data, error } = await supabase .from('todos') .update({ title: validatedFields.data.title, isCompleted: status }) .eq('id', id) .select(); if (error) { console.log('Error', error); return { type: 'error', message: 'Database Error: Failed to edit todo.', }; } revalidatePath('/todos'); return { type: 'success', message: `${validatedFields.data.title} updated successfully.`, resetKey: Date.now().toString(), }; } catch (error: any) { console.log('Error', error.message); return { type: 'error', message: 'Database Error: Failed to edit todo.', }; } } // =============================== deleteTodo =============================== export async function deleteTodo(id: number) { try { const { error } = await supabase.from('todos').delete().eq('id', id); if (error) { console.log('Error', error); return { type: 'error', message: 'Database Error: Failed to delete todo.', }; } revalidatePath('/todos'); return { type: 'success', message: `Todo deleted successfully.`, resetKey: Date.now().toString(), }; } catch (error: any) { console.log('Error', error.message); return { type: 'error', message: 'Database Error: Failed to delete todo.', }; } } ``` ## File Upload with Server Actions To demonstrate how we can Upload file with server actions, we will change the user avatar. By default OAuth will save the image url in `users.image`. For this we will using supabase Storage for saving user avatar, get the url and store url back to `users.image` ### 1.Create a profile page. ``` // app/profile/page.tsx import { auth } from '@/app/auth'; import { SignIn, SignOut } from '@/components/auth-components'; import ChangeAvatarForm from './ChangeAvatarForm'; export default async function PrivatePage() { const session = await auth(); if (!session?.user) return (

You need to login to perfom this action.

); return (

Hello {session.user.name}

); } ``` ### 2.Create A Change Avatar Form ``` // profile/ChangeAvatarForm.tsx import { auth } from '@/app/auth'; import { SignIn, SignOut } from '@/components/auth-components'; import Image from 'next/image'; import ChangeAvatarForm from './ChangeAvatarForm'; export default async function PrivatePage() { const session = await auth(); if (!session?.user) return (

You need to login to perform this action.

); return (

Hello {session.user.name}

); } ``` This is same as AddForm, we will change the input type to `file`. ### 3.Create action ``` // =============================== Change Avatar =============================== export async function changeAvatar(email: string, prevState: any, formData: FormData) { const avatar = formData.get('avatar') as File; if (!avatar) { return { type: 'error', message: 'Please select an avatar', }; } // Only images are allowed if (!avatar.type.includes('image')) { return { type: 'error', message: 'Only images are allowed', }; } // make sure file is less than 2MB if (avatar.size > 2 * 1024 * 1024) { return { type: 'error', message: 'File size must be less than 2MB', }; } try { const { data, error } = await supabase.storage.from('profile').upload(`public/${email}/${avatar.name}`, avatar, { upsert: true, }); if (error) { console.log('Error', error.message); return { type: 'error', message: `${error.message}`, }; } if (data.path) { const { data: avatar } = supabase.storage.from('profile').getPublicUrl(data.path); // change the url in User table in next-auth schema const { error: userDataError } = await nextAuthClient.from('users').update({ image: avatar.publicUrl }).eq('email', email); if (userDataError) { console.log('Error', userDataError); return { type: 'error', message: `${userDataError.message}`, }; } revalidatePath('/'); revalidatePath('/profile'); return { type: 'success', message: 'Avatar changed!', resetKey: Date.now().toString(), }; } } catch (error: any) { console.log('error', error); return { type: 'error', message: 'Database Error: Failed to change avatar.', }; } } ``` We validate the input such as only images are allowed and max size is 2mb. In this action, we will upload the file to the supabase storage and get back the url. Next we update the users table from next-auth schema. After update we revalidate the cache ``` revalidatePath('/'); revalidatePath('/profile'); ``` Because we have image in two places we have to revalidate two path. ## Conclusion Next.js 14 Server Actions offer a powerful and elegant way to manage data interactions in your React applications. By mastering this concept, you'll create more dynamic and performant web experiences for your users. ## Links - [Github Repo](https://github.com/patelvivekdev/server-actions/) - [Live Demo](https://server-actions-patelvivekdev.vercel.app/) - [Next.js 14 Server Actions](https://nextjs.org/docs/app/api-reference/functions/server-actions) - [React server actions](https://react.dev/reference/react/use-server#usage) - [React Form](https://react.dev/reference/react-dom/components/form#handle-form-submission-with-a-server-action) - [Supabase](https://supabase.com/) - [Next Auth](https://authjs.dev/getting-started/installation) - [Supabase Adapter](https://authjs.dev/getting-started/adapters/supabase) - [Shadcn ui](https://ui.shadcn.com/docs/installation/next)

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