Advanced

HTTP Server

BanglaCode can create HTTP servers using the server_chalu (start server) function. This allows you to build web applications and APIs.

Starting a Server

Use server_chalu to start an HTTP server on a specified port:

server.bangbanglacode
1// Basic HTTP server
2server_chalu(8080, kaj(req, res) {
3    uttor(res, "Namaskar from BanglaCode!");
4});
5
6dekho("Server running on port 8080");

Run the server and visit http://localhost:8080 in your browser.

Request Object

The request object contains information about the incoming HTTP request:

PropertyDescriptionExample
methodHTTP method"GET", "POST"
pathURL path"/users"
queryQuery string"id=123"
headersRequest headersMap of headers
bodyRequest bodyString or parsed JSON
1server_chalu(8080, kaj(req, res) {
2    dekho("Method:", req.method);
3    dekho("Path:", req.path);
4    dekho("Query:", req.query);
5    dekho("Headers:", req.headers);
6
7    uttor(res, "Request received!");
8});

Sending Responses

Text Response (uttor)

1// Basic text response
2server_chalu(8080, kaj(req, res) {
3    uttor(res, "Hello World");
4});
5
6// With status code
7server_chalu(8080, kaj(req, res) {
8    uttor(res, "Not Found", 404);
9});
10
11// With content type
12server_chalu(8080, kaj(req, res) {
13    uttor(res, "<h1>Hello</h1>", 200, "text/html");
14});

JSON Response (json_uttor)

1server_chalu(8080, kaj(req, res) {
2    dhoro data = {
3        status: "success",
4        message: "User created",
5        user: {
6            id: 1,
7            naam: "Rahim"
8        }
9    };
10
11    json_uttor(res, data);
12});
13
14// With custom status code
15server_chalu(8080, kaj(req, res) {
16    json_uttor(res, {error: "Not found"}, 404);
17});

Routing

1server_chalu(8080, kaj(req, res) {
2    // Simple routing based on path
3    jodi (req.path == "/") {
4        uttor(res, "Home Page", 200, "text/html");
5    } nahole jodi (req.path == "/about") {
6        uttor(res, "About Page", 200, "text/html");
7    } nahole jodi (req.path == "/api/users") {
8        json_uttor(res, {users: ["Rahim", "Karim"]});
9    } nahole {
10        uttor(res, "404 Not Found", 404);
11    }
12});

Method-based Routing

1server_chalu(8080, kaj(req, res) {
2    jodi (req.path == "/api/users") {
3        jodi (req.method == "GET") {
4            // List users
5            json_uttor(res, {users: getAllUsers()});
6
7        } nahole jodi (req.method == "POST") {
8            // Create user
9            dhoro body = json_poro(req.body);
10            dhoro user = createUser(body);
11            json_uttor(res, user, 201);
12
13        } nahole {
14            json_uttor(res, {error: "Method not allowed"}, 405);
15        }
16    } nahole {
17        json_uttor(res, {error: "Not found"}, 404);
18    }
19});

Practical Examples

Simple API Server

api_server.bangbanglacode
1// In-memory data store
2dhoro users = [];
3dhoro nextId = 1;
4
5kaj findUser(id) {
6    ghuriye (dhoro i = 0; i < dorghyo(users); i = i + 1) {
7        jodi (users[i].id == id) {
8            ferao users[i];
9        }
10    }
11    ferao khali;
12}
13
14server_chalu(8080, kaj(req, res) {
15    // CORS headers for API
16    res.headers["Access-Control-Allow-Origin"] = "*";
17
18    // Routes
19    jodi (req.path == "/api/users" ebong req.method == "GET") {
20        // List all users
21        json_uttor(res, {
22            success: sotti,
23            data: users,
24            count: dorghyo(users)
25        });
26
27    } nahole jodi (req.path == "/api/users" ebong req.method == "POST") {
28        // Create user
29        chesta {
30            dhoro body = json_poro(req.body);
31
32            dhoro user = {
33                id: nextId,
34                naam: body.naam,
35                email: body.email,
36                createdAt: somoy()
37            };
38
39            dhokao(users, user);
40            nextId = nextId + 1;
41
42            json_uttor(res, {success: sotti, data: user}, 201);
43        } dhoro_bhul (e) {
44            json_uttor(res, {success: mittha, error: "Invalid data"}, 400);
45        }
46
47    } nahole {
48        json_uttor(res, {success: mittha, error: "Not found"}, 404);
49    }
50});
51
52dekho("API Server running on http://localhost:8080");

HTML Web Server

web_server.bangbanglacode
1kaj renderHTML(title, content) {
2    ferao "<!DOCTYPE html>
3<html>
4<head>
5    <title>" + title + "</title>
6    <style>
7        body { font-family: sans-serif; max-width: 800px; margin: 0 auto; padding: 20px; }
8        h1 { color: #7c3aed; }
9    </style>
10</head>
11<body>
12    " + content + "
13</body>
14</html>";
15}
16
17server_chalu(8080, kaj(req, res) {
18    jodi (req.path == "/") {
19        dhoro html = renderHTML("Home", "
20            <h1>Namaskar!</h1>
21            <p>Welcome to BanglaCode Web Server</p>
22            <ul>
23                <li><a href='/about'>About</a></li>
24                <li><a href='/contact'>Contact</a></li>
25            </ul>
26        ");
27        uttor(res, html, 200, "text/html");
28
29    } nahole jodi (req.path == "/about") {
30        dhoro html = renderHTML("About", "
31            <h1>About Us</h1>
32            <p>BanglaCode is a Bengali programming language.</p>
33            <a href='/'>Back to Home</a>
34        ");
35        uttor(res, html, 200, "text/html");
36
37    } nahole {
38        dhoro html = renderHTML("404", "<h1>Page Not Found</h1>");
39        uttor(res, html, 404, "text/html");
40    }
41});
42
43dekho("Web server running on http://localhost:8080");

Form Handler

1server_chalu(8080, kaj(req, res) {
2    jodi (req.path == "/" ebong req.method == "GET") {
3        dhoro form = "<!DOCTYPE html>
4<html>
5<body>
6    <h1>Contact Form</h1>
7    <form method='POST' action='/submit'>
8        <p>Name: <input name='name'></p>
9        <p>Email: <input name='email' type='email'></p>
10        <p>Message: <textarea name='message'></textarea></p>
11        <button type='submit'>Send</button>
12    </form>
13</body>
14</html>";
15        uttor(res, form, 200, "text/html");
16
17    } nahole jodi (req.path == "/submit" ebong req.method == "POST") {
18        // Process form data
19        dekho("Form submitted:", req.body);
20
21        dhoro response = "<!DOCTYPE html>
22<html>
23<body>
24    <h1>Thank You!</h1>
25    <p>Your message has been received.</p>
26    <a href='/'>Back</a>
27</body>
28</html>";
29        uttor(res, response, 200, "text/html");
30    }
31});

HTTP Client (anun)

Use anun (meaning "fetch" or "bring") to make HTTP requests:

1// Simple GET request
2dhoro response = anun("https://api.example.com/data");
3dekho(response);
4
5// Parse JSON response
6dhoro data = json_poro(response.body);
7dekho(data);

Enhanced HTTP Client (anun)

anun() now supports all HTTP methods via an optional options map. Backward-compatible: one-argument GET still works.

// GET (unchanged) dhoro res = anun("https://api.example.com/users"); // POST with JSON body dhoro res = anun("https://api.example.com/users", { "method": "POST", "body": json_banao({"name": "Ankan", "email": "a@b.com"}), "headers": {"Content-Type": "application/json"} }); // PUT dhoro res = anun("https://api.example.com/users/1", { "method": "PUT", "body": json_banao({"name": "Updated"}) }); // DELETE dhoro res = anun("https://api.example.com/users/1", { "method": "DELETE" }); dekho("Status:", res["status"]); dhoro data = json_poro(res["body"]);

Async HTTP Client (anun_async)

proyash kaj createUser(userData) { dhoro res = opekha anun_async("https://api.example.com/users", { "method": "POST", "body": json_banao(userData), "headers": {"Content-Type": "application/json"} }); ferao json_poro(res["body"]); } dhoro user = opekha createUser({"name": "Ankan"}); dekho("Created:", user);

Request Object Reference

All fields available on req inside route handlers:

FieldTypeDescription
req["method"]STRINGHTTP method: GET, POST, PUT, ...
req["path"]STRINGRequest path: /users/123
req["ip"]STRINGClient IP address
req["headers"]MAPAll request headers
req["body"]STRINGRaw request body
req["json"]MAP/NULLAuto-parsed JSON body (when Content-Type: application/json)
req["form"]MAP/NULLURL-encoded form data (when Content-Type: application/x-www-form-urlencoded)
req["params"]MAPPath params: route /users/:id → req["params"]["id"]
req["query"]MAPParsed query string: ?q=hi → req["query"]["q"]
req["query_raw"]STRINGRaw query string: "q=hi&page=2"
req["kukis"]MAPParsed cookies: req["kukis"]["session"]

Performance Helpers Reference

FunctionBengaliDescription
goti_shima(app, max, window)গতি সীমাRate limit: max requests per window seconds per IP
sankochon_chalu(app)সংকোচন চালুEnable gzip compression
somoy_shima(app, secs)সময় সীমাRequest timeout in seconds
akaar_shima(app, bytes)আকার সীমাMax request body size in bytes
log_chalu(app)লগ চালুEnable request logging
cors_chharpao(app, opts?)ছাড়পাওEnable CORS
file_dao(app, url, dir)ফাইল দাওServe static files
ghurao(res, url, status?)ঘোরাওHTTP redirect (default 302)
kuki_rakho(res, name, val, opts?)কুকি রাখোSet response cookie
html_uttor(res, filepath)HTML উত্তরServe HTML file
bhul_sambhalo(app, handler)ভুল সামলাওGlobal error middleware

Best Practices

  • Always validate input - Never trust client data
  • Use appropriate status codes - 200 for success, 404 for not found, etc.
  • Set correct content types - Especially for JSON and HTML
  • Handle errors gracefully - Use bhul_sambhalo() for centralized error handling
  • Use JSON for APIs - It's the standard for data exchange
  • Enable production features - cors_chharpao, goti_shima, sankochon_chalu, somoy_shima for production deployments