Cliente HTTP (std::http)
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std::http expõe o sub-módulo client para comunicação HTTP síncrona com APIs
externas. As chamadas retornam um par (resp, err): quando err != nil ocorreu
uma falha de rede ou de protocolo; caso contrário resp contém status, ok,
headers e body.
Nota: todos os exemplos abaixo executam requisições de rede reais e por isso são marcados como
| norunno sandbox WASM. Rode localmente comzolo run.
GET simples
A operação mais comum: buscar um recurso por URL.
Exemplo de GET com tratamento de erro; a resposta traz status, ok e body.
// Feature: http.client.get — HTTP GET request
// When to use: consume REST APIs, download pages, healthchecks.
// Response: { status, headers, body, status_text, ok } or (nil, err) on failure.
//
// SKIP: this example performs a live HTTP request (httpbin.org).
// In offline / sandboxed environments the call surfaces an internal
// error from the runtime rather than a clean (nil, err) result, so
// the body of the function is shown only as a comment.
use std::http
use std::log
fn fetch_status(url: str) {
// let resp, err = http.client.get(url)
// if err != nil {
// log.error("failure: {err}")
// return nil
// }
// return resp
print("(would GET {url})")
return nil
}
let _ = fetch_status("http://httpbin.org/get")
// Expected response shape (when the request succeeds):
// resp.status -> 200
// resp.ok -> true
// resp.headers["content-type"] -> "application/json"
// resp.body -> raw response body string
Requer a CLI/host do Zolo — abra no playground ou rode localmente.
POST com corpo JSON
Envie dados estruturados combinando std::json para serializar o payload e
http.client.post para transmiti-lo.
POST com payload JSON e leitura do eco retornado pelo servidor.
// Feature: http.client.post — POST with a JSON body
// When to use: create resources, send webhooks, talk to REST APIs.
//
// SKIP: this example performs a live HTTP request (httpbin.org).
// In offline / sandboxed environments the call surfaces an internal
// error from the runtime rather than a clean (nil, err) result, so
// the network call is shown only as a comment.
use std::http
use std::json
use std::log
let payload = json.encode(#{
user_id: 42,
action: "login",
ts: 1700000000,
})
let headers = #{
"Content-Type": "application/json",
Accept: "application/json",
}
let ct = headers["Content-Type"]
print("payload: {payload}")
print("Content-Type: {ct}")
// Signature: http.client.post(url, body, headers?)
// let resp, err = http.client.post("http://httpbin.org/post", payload, headers)
//
// if err != nil {
// log.error("error: {err}")
// } else {
// print(resp.status) // expected: 200
// // The httpbin server echoes the body back — try decoding it.
// let echo = json.decode(resp.body)
// print(echo["json"]["action"]) // expected: login
// }
Requer a CLI/host do Zolo — abra no playground ou rode localmente.
Cabeçalhos personalizados
Autenticação Bearer, User-Agent e chaves de idempotência são passados como
mapa #{chave: valor} no argumento de cabeçalhos (segundo parâmetro no GET,
terceiro no POST/PUT). Os métodos put, delete e patch seguem o mesmo
padrão.
Cabeçalhos de autorização e User-Agent; visão geral de PUT/DELETE/PATCH.
// Feature: http.client — custom headers in requests
// When to use: authentication (Bearer), custom User-Agent, Accept-Language, idempotency keys.
//
// SKIP: this example performs a live HTTP request (httpbin.org).
// In offline / sandboxed environments the call surfaces an internal
// error from the runtime rather than a clean (nil, err) result, so
// the network call is shown only as a comment.
use std::http
let headers = #{
Authorization: "Bearer secret-token",
"User-Agent": "zolo-client/0.1",
Accept: "application/json",
"X-Request-Id": "abc123",
}
let auth = headers["Authorization"]
let ua = headers["User-Agent"]
print("Authorization: {auth}")
print("User-Agent: {ua}")
// GET with headers (optional as the second argument).
// let resp, err = http.client.get("http://httpbin.org/headers", headers)
//
// if err == nil {
// print(resp.status) // expected: 200
// print(resp.body) // httpbin echoes the headers it received
// }
// PUT/DELETE/PATCH follow the same pattern:
// http.client.put(url, body, headers?)
// http.client.delete(url, headers?)
// http.client.patch(url, body, headers?)
Requer a CLI/host do Zolo — abra no playground ou rode localmente.
Desafio
Adapte o exemplo de POST para enviar um webhook e valide a assinatura HMAC
usando std::hash.hmac (veja o módulo hash).
Veja também