文档JavaScript 后端
从 Express 到 Nexy
在 Nexy 中,Express 路由变成 src/routes/ 下的 Python 文件:app.get 是 GET 函数,req 变成类型参数,res.json 变成返回值,app.use 变成配置字段或 middleware.py。
下面的每个部分都显示了 Express 习惯,然后是 Nexy 中的相同内容。
一条路线
import express from "express"; const app = express(); app.get("/api/hello", (req, res) => { res.json({ message: "Hello" });}); app.listen(3000);文件路径是 URL,函数名称是方法,返回值是 JSON 正文:
async def GET(): return {"message": "Hello"}req.params
app.get("/api/users/:id", (req, res) => { const id = Number(req.params.id); if (Number.isNaN(id)) return res.status(404).end(); res.json({ id });});:id 是一个 [id] 段,类型注释进行转换,404:
async def GET(id: int): return {"id": id}* 通配符是 [...rest].py 文件。
req.query
app.get("/api/search", (req, res) => { const q = req.query.q ?? ""; const page = Number(req.query.page ?? 1); res.json({ q, page });});async def GET(q: str = "", page: int = 1): return {"q": q, "page": page}?page=abc 使用失败的参数回答 422,而不是 NaN。
req.body 和验证
import { z } from "zod"; app.use(express.json()); const NewItem = z.object({ name: z.string(), price: z.number().positive() }); app.post("/api/items", (req, res) => { const parsed = NewItem.safeParse(req.body); if (!parsed.success) return res.status(422).json(parsed.error); res.status(201).json(parsed.data);});在函数运行之前,根据 Pydantic 模型对主体进行解析和验证:
from pydantic import BaseModel, Field from nexy.http import JSONResponse class NewItem(BaseModel): name: str price: float = Field(gt=0) async def POST(item: NewItem): return JSONResponse(item.model_dump(), status_code=201)express.Router()
const admin = express.Router(); admin.get("/stats", (req, res) => res.json({ users: 3 })); app.use("/admin", admin);该文件夹是挂载路径:
async def GET(): return {"users": 3}路由中间件
function requireAdmin(req, res, next) { if (req.get("x-role") !== "admin") return res.status(403).json({ error: "Admins only" }); next();} admin.use(requireAdmin);dependencies.py 在其文件夹的每个路由之前运行。引发会停止请求,就像不调用 next() 一样:
from nexy.http import Header, HTTPException def require_admin(x_role: str = Header("")) -> None: if x_role != "admin": raise HTTPException(status_code=403, detail="Admins only") dependencies = [require_admin]app.use 中间件
app.use((req, res, next) => { const start = Date.now(); res.on("finish", () => console.log(req.method, req.url, Date.now() - start)); next();});路由根部的 middleware.py 包装每个请求; call_next 是 next():
import time from nexy.http import Request async def middleware(request: Request, call_next): start = time.perf_counter() response = await call_next(request) response.headers["x-time-ms"] = f"{(time.perf_counter() - start) * 1000:.1f}" return responsecors、compression、helmet 型主机
import compression from "compression";import cors from "cors"; app.use(cors({ origin: "https://example.com" }));app.use(compression());from nexy.core.models import NexyConfigModel class NexyConfig(NexyConfigModel): useCORS = {"allow_origins": ["https://example.com"]} useGZip = {"minimum_size": 1000} useTrustedHost = {"allowed_hosts": ["example.com", "*.example.com"]} useSession = {"secret_key": "change-me"}饼干
import cookieParser from "cookie-parser"; app.use(cookieParser()); app.post("/api/theme", (req, res) => { res.cookie("theme", "dark").json({ theme: "dark" });}); app.get("/api/theme", (req, res) => res.json({ theme: req.cookies.theme ?? "light" }));cookie是读取的参数,写入响应的方法:
from nexy.http import Cookie, JSONResponse async def GET(theme: str = Cookie("light")): return {"theme": theme} async def POST(): response = JSONResponse({"theme": "dark"}) response.set_cookie("theme", "dark") return responseexpress-session
import session from "express-session"; app.use(session({ secret: "change-me" })); app.post("/api/login", (req, res) => { req.session.user = req.body.name; res.json({ user: req.session.user });});nexyconfig.py(上面)中的 useSession 打开会话; request.session 是一个字典:
from pydantic import BaseModel from nexy.http import Request class Login(BaseModel): name: str async def POST(request: Request, body: Login): request.session["user"] = body.name return {"user": body.name}res.redirect
app.get("/old", (req, res) => res.redirect(301, "/new"));from nexy.http import RedirectResponse async def GET(): return RedirectResponse("/new", status_code=301)使用 multer 上传文件
import multer from "multer"; const upload = multer({ limits: { fileSize: 1_000_000 } }); app.post("/api/upload", upload.single("file"), (req, res) => { res.json({ name: req.file.originalname, size: req.file.size });});from nexy.http import HTTPException, UploadFile async def POST(file: UploadFile): data = await file.read() if len(data) > 1_000_000: raise HTTPException(status_code=413, detail="File too large") return {"name": file.filename, "size": len(data)}使用 EJS 或 Pug 的视图
app.set("view engine", "ejs"); app.get("/users", (req, res) => { res.render("users", { users: [{ name: "Ada" }, { name: "Alan" }] });});<ul> <% users.forEach((user) => { %> <li><%= user.name %></li> <% }) %></ul>.nexy 页面同时包含路线和视图:
users = [{"name": "Ada"}, {"name": "Alan"}]<ul> {% for user in users %} <li>{{ user.name }}</li> {% endfor %}</ul><%= %> 转义,而 {{ }} 不转义:转义访问者用 {{ value | e }} 键入的内容。
express.static
app.use(express.static("public"));没什么可写的:public/ 的服务地点是 /。
404 处理程序和错误处理程序
app.use((req, res) => res.status(404).send("<h1>Not found</h1>")); app.use((err, req, res, next) => { console.error(err); res.status(500).send("<h1>Something broke</h1>");});路由根目录下有两个文件。 API 客户端仍然获取 JSON,浏览器获取页面:
<h1>Not found</h1><h1>Something broke</h1>WebSockets 与 ws
import { WebSocketServer } from "ws"; const wss = new WebSocketServer({ server, path: "/ws/echo" });wss.on("connection", (socket) => socket.on("message", (data) => socket.send(data)));from fastapi import WebSocket async def SOCKET(websocket: WebSocket): await websocket.accept() await websocket.send_text(await websocket.receive_text())使用 Jest 和 Supertest 进行测试
import request from "supertest";import { app } from "./app.js"; test("hello", async () => { const res = await request(app).get("/api/hello"); expect(res.body).toEqual({ message: "Hello" });});from fastapi.testclient import TestClient from nexy.app import app def test_hello(): assert TestClient(app).get("/api/hello").json() == {"message": "Hello"}跑步
| 快递 | 内克西 |
|---|---|
npm init + npm i express |
nx new |
nodemon index.js |
nx dev |
NODE_ENV=production node index.js |
nx build,然后 nx start |
npm test |
nx test |
| 没有 API 文档 | /docs,列出每条 .py 路线 |
保留您的 React 前端
如果 Express 应用程序提供 React SPA,则组件将移动到 src/components/ 并呈现为 .nexy 页面的岛屿,或者整个站点移动到使用 useCSR = True 的客户端路由。参见岛屿 和CSR。