Next.js: Update server component after client component modifies data

Question

I'm still trying to understand this scenario. Can anyone suggest what is the correct way to do this in Next.js 13?

I display a list of users in a server component, for example like this (using MongoDB):

// UsersList.jsx
const UsersList = () => {
  const users = await usersCollection.getUsers()

  return (
  <div>
    {users.map(user) => <div>{user}</div>}
  </div>
  )
}

On the same page I also defined the client component for adding users:

// UsersEdit.jsx
'use client'
const UsersEdit = () => {
  const handleAdd() => // calls POST to /api/users
  return // render input + button
}

Both are displayed together in the server component page, as shown below:

// page.jsx
const Users = () => {
  return (
  <div>
    <UsersList />
    <UsersEdit />
  </div>
  )
}

How should I "reload" or "notify" UsersList that a new user has been added to the collection to force it to show new/updated users?

Answer 1

https://stackoverflow.com/a/75127011/17964403 This is great for mutating on the client side, but if you want to do something like searching/filtering using input from the client, and want to re-fetch the same data, you can do something like

const [searchterm, setSearchterm] = useState("");
const handleSearch = (e) => {
   e.preventDefault();
   if(!searchterm)return
   router.push(/home?search=`${searchterm}`)
}

In the server component you will receive the search parameter as a prop, see if the search parameter exists, if it exists then pass that parameter in the fetch call and you will get the filtered items.

Answer 2

To reflect data updated by the client component on the server component, you can use router.refresh(), where router is useRouter(). Here's an example of using a to-do list app:

// app/page.tsx

import Todo from "./todo";
async function getTodos() {
  const res = await fetch("https://api.example.com/todos", { cache: 'no-store' });
  const todos = await res.json();
  return todos;
}

export default async function Page() {
  const todos = await getTodos();
  return (
    <ul>
      {todos.map((todo) => (
        <Todo key={todo.id} {...todo} />
      ))}
    </ul>
  );
}

// app/todo.tsx

"use client";

import { useRouter } from 'next/navigation';
import { useState, useTransition } from 'react';

export default function Todo(todo) {
  const router = useRouter();
  const [isPending, startTransition] = useTransition();
  const [isFetching, setIsFetching] = useState(false);

  // Create inline loading UI
  const isMutating = isFetching || isPending;

  async function handleChange() {
    setIsFetching(true);
    // Mutate external data source
    await fetch(`https://api.example.com/todo/${todo.id}`, {
      method: 'PUT',
      body: JSON.stringify({ completed: !todo.completed }),
    });
    setIsFetching(false);

    startTransition(() => {
      // Refresh the current route and fetch new data from the server without
      // losing client-side browser or React state.
      router.refresh();
    });
  }

  return (
    <li style={{ opacity: !isMutating ? 1 : 0.7 }}>
      <input
        type="checkbox"
        checked={todo.completed}
        onChange={handleChange}
        disabled={isPending}
      />
      {todo.title}
    </li>
  );
}

⚠️: The crawl request is cached. That's why cache: 'no-store' in this example.