Rest API Guide

Ülevaade

Allpool on samm-sammuline juhend, kuidas käivitada lihtne Node.js + Express REST API ja sellele brauserist andmeid lisada (ilma Postmanita). Sobib nii CodeSandbox kui ka VS Code jaoks.

Start CodeSandboxis või VS Code’is

1. Ava CodeSandbox (Node sandbox) või loo kaust lokaalselt ja ava see VS Code’is.
2. Initsialiseeri projekt:

   npm init -y

3. Paigalda sõltuvused:

   npm install express cors

Serveri kood (index.js)

// index.js
const express = require("express");
const cors = require("cors");
const path = require("path");

const app = express();
app.use(cors());
app.use(express.json());

// Sinu statiline esipaneel (public/admin.html)
app.use("/", express.static(path.join(__dirname, "public")));

let widgets = [
  { id: 1, name: "Foo", price: 9.99 },
  { id: 2, name: "Bar", price: 19.99 },
  { id: 3, name: "Baz", price: 29.99 },
];

app.get("/widgets", (req, res) => res.json(widgets));

app.get("/widgets/:id", (req, res) => {
  const id = Number(req.params.id);
  const w = widgets.find(x => x.id === id);
  if (!w) return res.status(404).json({ error: "Widget not found" });
  res.json(w);
});

app.post("/widgets", (req, res) => {
  const { name, price } = req.body;
  if (!name || typeof name !== "string" || name.trim() === "")
    return res.status(400).json({ error: 'Field "name" is required (string).' });
  if (price === undefined || isNaN(Number(price)) || Number(price) < 0)
    return res.status(400).json({ error: 'Field "price" is required (number ≥ 0).' });

  const newWidget = { id: widgets.length + 1, name: name.trim(), price: Number(price) };
  widgets.push(newWidget);
  res.status(201).json(newWidget);
});

app.delete("/widgets/:id", (req, res) => {
  const id = Number(req.params.id);
  const i = widgets.findIndex(x => x.id === id);
  if (i === -1) return res.status(404).json({ error: "Widget not found" });
  const removed = widgets.splice(i, 1)[0];
  res.json({ deleted: removed });
});

app.put("/widgets/:id", (req, res) => {
  const id = Number(req.params.id);
  const w = widgets.find(x => x.id === id);
  if (!w) return res.status(404).json({ error: "Widget not found" });

  const { name, price } = req.body;
  if (name !== undefined) {
    if (typeof name !== "string" || name.trim() === "")
      return res.status(400).json({ error: 'Field "name" must be non-empty string.' });
    w.name = name.trim();
  }
  if (price !== undefined) {
    if (isNaN(Number(price)) || Number(price) < 0)
      return res.status(400).json({ error: 'Field "price" must be number ≥ 0.' });
    w.price = Number(price);
  }
  res.json(w);
});

const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(`API running at http://localhost:${PORT}`);
});

package.json

{
  "name": "rest-api-csb",
  "version": "1.0.0",
  "main": "index.js",
  "type": "commonjs",
  "scripts": { "start": "node index.js" },
  "dependencies": { "cors": "^2.8.5", "express": "^4.19.2" }
}

Käivita server

1. Terminalis käivita:

   node index.js

2. Ava brauseris http://localhost:8080 (või CodeSandboxi eelvaade).
3. Testi API-d: /widgets, /widgets/1 jne.

Kuvatõmmis: paketid

Kuvatõmmis: API vastus

Andmete lisamine brauserist (admin.html)

Loo fail public/admin.html ning ava /admin.html. Nii saad andmeid lisada/vaadata/kustutada ilma Postmanita.

Pärast lisamist näed tulemust:

Kiirviited ja nipid

• CORS on lubatud: app.use(cors()).
• JSON keha: app.use(express.json()).
• PUT võimaldab lihtsa muutmise (nimi/hind).
• CodeSandboxis kasuta alati process.env.PORT.