ExpressIntermediate

Express Body Parsing

express.json(), urlencoded, raw, text — Request body parse করার বাংলা গাইড।

10টি অংশবাংলা ভাষায়

POST/PUT/PATCH request-এ client body পাঠায় — JSON, form, raw ইত্যাদি। Express-এর built-in middleware দিয়ে এগুলো parse করা হয়।

express.json()

// JSON body parse
app.use(express.json());

// limit ও strict option সহ
app.use(express.json({
  limit: "10mb", // max body size
  strict: true,  // only objects & arrays
}));

// POST /users with body {"name":"রহিম"}
app.post("/users", (req, res) => {
  console.log(req.body.name); // "রহিম"
  res.json(req.body);
});

express.urlencoded()

// HTML form body parse
app.use(express.urlencoded({ extended: true }));

// /login form-এ (username=rahim&password=123)
app.post("/login", (req, res) => {
  console.log(req.body.username); // "rahim"
  console.log(req.body.password); // "123"
});

express.text() ও raw()

// Plain text body
app.use(express.text());

app.post("/note", (req, res) => {
  console.log(req.body); // "my raw text"
});

// Raw/binary body
app.use(express.raw({ type: "application/octet-stream" }));

app.post("/upload", (req, res) => {
  console.log(req.body.length); // bytes
});

Validation সহ

// Empty body check
app.post("/users", (req, res) => {
  if (!req.body || Object.keys(req.body).length === 0) {
    return res.status(400).json({ error: "Body খালি" });
  }
  res.json(req.body);
});

সতর্কতা

express.json()-এ limit না দিলে default 100kb। বড় payload পাঠালে limit set করুন নাহলে Error হবে।

শেষ প্যারায় নিজে practice করুন — কোড কপি করে নিজের এডিটরে চালিয়ে দেখুন।