Parámetros de Ruta y Middleware

:id, req.params, req.query y ?? para valores opcionales.

// Feature: HTTP server — path params (`:id`) and query string

// Syntax: `:name` in the route; read via `req.params.name` and `req.query.k`.

// When to use: REST routes with IDs, slugs, optional filters.


use std::http

@get("/users/:id")
fn get_user(req) {
  // `req.params` carries the matched segments.

  let id = req.params.id
  return #{
    id,
    name: "User {id}",
  }
}

@get("/search")
fn search(req) {
  // `req.query` is a map; `??` applies a default if absent.

  let q = req.query.q ?? "(empty)"
  let limit = req.query.limit ?? "10"
  return #{
    q,
    limit,
  }
}

@get("/posts/:author/:slug")
fn get_post(req) {
  return #{
    author: req.params.author,
    slug: req.params.slug,
  }
}

http.serve(3002)
// expected when running:

//   curl http://localhost:3002/users/42                -> {"id":"42","name":"User 42"}

//   curl 'http://localhost:3002/search?q=zolo&limit=5' -> {"q":"zolo","limit":"5"}

//   curl http://localhost:3002/posts/devzolo/hello     -> {"author":"devzolo","slug":"hello"}

Requiere la CLI o el host de Zolo; ábrelo en el playground o ejecútalo localmente.

Middleware de log y de CORS — next(req) y .with_headers(#{...}).

// Feature: HTTP server — middleware via pipe

// Syntax: `fn mw(req, next) { ... return next(req) }` and

//         `router |> http.middleware(mw)`

// When to use: logging, CORS, authentication, common headers —

// cross-cutting code shared across routes.


use std::http

// Middleware 1: log every request.

fn logger(req, next) {
  print("[{req.method}] {req.path}")
  return next(req)
}

// Middleware 2: add CORS headers to the response.

fn cors(req, next) {
  return next(req).with_headers(#{
    "Access-Control-Allow-Origin": "*",
    "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE",
    "Access-Control-Allow-Headers": "Content-Type",
  })
}

fn api_health() {
  return #{status: "ok"}
}

fn api_echo(req) {
  return req.json()
}

let router = http.router()
  |> http.get("/api/health", api_health)
  |> http.post("/api/echo", api_echo)
  |> http.middleware(logger)
  |> http.middleware(cors)

http.serve(3003, router)
// expected when running:

//   curl http://localhost:3003/api/health      -> {"status":"ok"}

//   curl -i http://localhost:3003/api/health   -> CORS headers present

Requiere la CLI o el host de Zolo; ábrelo en el playground o ejecútalo localmente.