Understanding Next.js in 2 Minutes: The Ultimate React Framework!

1// app/blog/page.tsx
2import { PostList } from '@/components/server/PostList';
3import { Suspense } from 'react';
4
5export default async function BlogPage() {
6  return (
7    <main className="container mx-auto px-4 py-8">
8      <h1 className="text-4xl font-bold mb-8">Our Blog</h1>
9      <Suspense fallback={<p>Loading posts...</p>}>
10        <PostList />
11      </Suspense>
12    </main>
13  );
14}
15
16// components/server/PostList.tsx
17async function getPosts() {
18  const posts = await db.post.findMany();
19  return posts;
20}
21
22export async function PostList() {
23  const posts = await getPosts();
24
25  return (
26    <div className="grid gap-6 md:grid-cols-2">
27      {posts.map(post => (
28        <article key={post.id} className="p-4 rounded-lg border">
29          <h2 className="text-xl font-semibold">{post.title}</h2>
30          <p className="mt-2 text-gray-600">{post.excerpt}</p>
31        </article>
32      ))}
33    </div>
34  );
35}

1// components/client/SearchBar.tsx
2'use client';
3
4import { useState } from 'react';
5import { useRouter } from 'next/navigation';
6
7export function SearchBar() {
8  const [query, setQuery] = useState('');
9  const router = useRouter();
10
11  function handleSearch(e: React.FormEvent) {
12    e.preventDefault();
13    router.push(`/search?q=${encodeURIComponent(query)}`);
14  }
15
16  return (
17    <form onSubmit={handleSearch} className="flex gap-2">
18      <input
19        type="search"
20        value={query}
21        onChange={(e) => setQuery(e.target.value)}
22        placeholder="Search..."
23        className="px-4 py-2 rounded border"
24      />
25      <button type="submit" className="px-4 py-2 bg-blue-500 text-white rounded">
26        Search
27      </button>
28    </form>
29  );
30}

1// lib/actions.ts
2'use server';
3
4import { revalidatePath } from 'next/cache';
5import { redirect } from 'next/navigation';
6import { z } from 'zod';
7
8const PostSchema = z.object({
9  title: z.string().min(3, "Title must contain at least 3 characters"),
10  content: z.string().min(10, "Content must contain at least 10 characters")
11});
12
13export async function createPost(formData: FormData) {
14  const data = {
15    title: formData.get('title'),
16    content: formData.get('content')
17  };
18
19  const result = PostSchema.safeParse(data);
20
21  if (!result.success) {
22    return { error: result.error.flatten() };
23  }
24
25  const post = await db.post.create({
26    data: result.data
27  });
28
29  revalidatePath('/blog');
30  redirect('/blog');
31}
32
33// app/blog/new/page.tsx
34import { createPost } from '@/lib/actions';
35
36export default function NewPostPage() {
37  return (
38    <form action={createPost} className="space-y-4 max-w-lg mx-auto">
39      <div>
40        <label htmlFor="title" className="block text-sm font-medium">
41          Title
42        </label>
43        <input
44          type="text"
45          name="title"
46          id="title"
47          required
48          className="mt-1 block w-full rounded-md border-gray-300"
49        />
50      </div>
51      <div>
52        <label htmlFor="content" className="block text-sm font-medium">
53          Content
54        </label>
55        <textarea
56          name="content"
57          id="content"
58          required
59          rows={5}
60          className="mt-1 block w-full rounded-md border-gray-300"
61        />
62      </div>
63      <button
64        type="submit"
65        className="w-full py-2 px-4 bg-blue-500 text-white rounded-md"
66      >
67        Publish
68      </button>
69    </form>
70  );
71}

1// app/api/posts/route.ts
2import { NextResponse } from 'next/server';
3import { z } from 'zod';
4
5const PostSchema = z.object({
6  title: z.string().min(3),
7  content: z.string().min(10),
8});
9
10export async function GET(request: Request) {
11  const { searchParams } = new URL(request.url);
12  const query = searchParams.get('q');
13
14  const posts = await db.post.findMany({
15    where: query
16      ? {
17          OR: [
18            { title: { contains: query } },
19            { content: { contains: query } },
20          ],
21        }
22      : undefined,
23  });
24
25  return NextResponse.json({ posts });
26}
27
28export async function POST(request: Request) {
29  try {
30    const body = await request.json();
31    const result = PostSchema.safeParse(body);
32
33    if (!result.success) {
34      return NextResponse.json(
35        { error: result.error.flatten() },
36        { status: 400 },
37      );
38    }
39
40    const post = await db.post.create({
41      data: result.data,
42    });
43
44    return NextResponse.json(post, { status: 201 });
45  } catch (error) {
46    return NextResponse.json({ error: 'Server error' }, { status: 500 });
47  }
48}

1import { Suspense } from 'react';
2import { PostList } from '@/components/server/PostList';
3import { SidebarNav } from '@/components/server/SidebarNav';
4import { Loading } from '@/components/ui/Loading';
5
6export default function BlogLayout({
7  children
8}: {
9  children: React.ReactNode
10}) {
11  return (
12    <div className="flex gap-8">
13      <Suspense fallback={<Loading />}>
14        <SidebarNav />
15      </Suspense>
16      <main className="flex-1">
17        <Suspense fallback={<Loading />}>
18          {children}
19        </Suspense>
20      </main>
21      <aside className="w-64">
22        <Suspense fallback={<Loading />}>
23          <PostList type="recent" />
24        </Suspense>
25      </aside>
26    </div>
27  );
28}

1// app/error.tsx
2'use client';
3
4export default function Error({
5  error,
6  reset
7}: {
8  error: Error & { digest?: string };
9  reset: () => void;
10}) {
11  return (
12    <div className="flex flex-col items-center justify-center min-h-[400px]">
13      <h2 className="text-2xl font-bold mb-4">
14        An error has occurred!
15      </h2>
16      <button
17        onClick={() => reset()}
18        className="px-4 py-2 bg-blue-500 text-white rounded"
19      >
20        Try again
21      </button>
22    </div>
23  );
24}

1import Image from 'next/image';
2
3export function Avatar({ src, alt }: { src: string; alt: string }) {
4  return (
5    <div className="relative w-10 h-10">
6      <Image
7        src={src}
8        alt={alt}
9        fill
10        sizes="40px"
11        className="rounded-full object-cover"
12        priority
13      />
14    </div>
15  );
16}