处理程序
处理程序是响应每个路由请求的函数。
接受请求信息并返回响应给客户端。
在其他框架中，处理程序也被称为 控制器。
typescript
import { Server, defineRoutes, createHandler } from 'vafast'
const routes = defineRoutes([
{
method: 'GET',
path: '/',
handler: createHandler(() => 'hello world')
}
])基本用法
简单响应
最简单的处理程序直接返回数据：
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/',
handler: createHandler(() => 'Hello World')
},
{
method: 'GET',
path: '/json',
handler: createHandler(() => ({ message: 'Hello World' }))
},
{
method: 'GET',
path: '/html',
handler: createHandler(() => '<h1>Hello World</h1>')
}
])访问请求信息
处理程序可以访问请求的各种信息：
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/info',
handler: createHandler(({ req, headers, query }) => {
return {
url: req.url,
method: req.method,
userAgent: headers['user-agent'],
query: query.search || 'default'
}
})
}
])异步处理
处理程序支持异步操作：
typescript
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(async ({ body }) => {
// 模拟数据库操作
const user = await createUser(body)
return user
})
}
])参数解构
Vafast 使用参数解构来提供类型安全的访问：
基本参数
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/user/:id',
handler: createHandler(({ params, query, headers }) => {
const userId = params.id
const page = query.page || '1'
const auth = headers.authorization
return `User ${userId}, Page ${page}, Auth: ${auth}`
})
}
])请求体
typescript
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(async ({ body }) => {
const { name, email, age } = body
if (!name || !email) {
return new Response('Name and email are required', { status: 400 })
}
return { name, email, age: age || 18 }
})
}
])查询参数
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/search',
handler: createHandler(({ query }) => {
const { q, page = '1', limit = '10', sort = 'name' } = query
return {
query: q,
page: parseInt(page),
limit: parseInt(limit),
sort,
results: []
}
})
}
])响应处理
自动响应类型
Vafast 会自动处理不同类型的返回值：
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/string',
handler: createHandler(() => 'Plain text') // 返回 text/plain
},
{
method: 'GET',
path: '/json',
handler: createHandler(() => ({ data: 'JSON' })) // 返回 application/json
},
{
method: 'GET',
path: '/html',
handler: createHandler(() => '<h1>HTML</h1>') // 返回 text/html
},
{
method: 'GET',
path: '/number',
handler: createHandler(() => 42) // 返回 text/plain
}
])手动响应控制
如果需要更精细的控制，可以返回 Response 对象：
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/custom',
handler: createHandler(() => {
return new Response('Custom response', {
status: 200,
headers: {
'Content-Type': 'text/plain',
'X-Custom-Header': 'value'
}
})
})
},
{
method: 'GET',
path: '/redirect',
handler: createHandler(() => {
return new Response(null, {
status: 302,
headers: {
'Location': '/new-page'
}
})
})
}
])错误响应
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/user/:id',
handler: createHandler(({ params }) => {
const userId = params.id
if (!userId || isNaN(Number(userId))) {
return new Response('Invalid user ID', { status: 400 })
}
if (userId === '999') {
return new Response('User not found', { status: 404 })
}
return { id: userId, name: 'John Doe' }
})
}
])中间件集成
处理程序可以与中间件配合使用：
typescript
const authMiddleware = async (req: Request, next: () => Promise<Response>) => {
const token = req.headers.get('authorization')
if (!token) {
return new Response('Unauthorized', { status: 401 })
}
return await next()
}
const routes = defineRoutes([
{
method: 'GET',
path: '/protected',
handler: createHandler(() => 'Protected content'),
middleware: [authMiddleware]
}
])Schema 验证
处理程序可以与 TypeBox 验证集成，使用两参数形式：
typescript
import { Type } from '@sinclair/typebox'
const userSchema = Type.Object({
name: Type.String({ minLength: 1 }),
email: Type.String({ format: 'email' }),
age: Type.Optional(Type.Number({ minimum: 0 }))
})
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(
{ body: userSchema },
({ body }) => {
// body 已经通过验证，类型安全
const { name, email, age } = body
return { name, email, age: age || 18 }
}
)
}
])最佳实践
1. 保持处理程序简洁
typescript
// ✅ 好的做法
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(async ({ body }) => {
const user = await createUser(body)
return user
})
}
])
// ❌ 避免的做法
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(async ({ body }) => {
// 不要在这里放太多业务逻辑
const { name, email, age, address, phone, preferences, ... } = body
// 复杂的验证逻辑
// 数据库操作
// 邮件发送
// 日志记录
// 等等...
})
}
])2. 使用适当的错误处理
typescript
const routes = defineRoutes([
{
method: 'GET',
path: '/user/:id',
handler: createHandler(async ({ params }) => {
try {
const user = await getUserById(params.id)
if (!user) {
return new Response('User not found', { status: 404 })
}
return user
} catch (error) {
console.error('Error fetching user:', error)
return new Response('Internal server error', { status: 500 })
}
})
}
])3. 利用类型安全
typescript
interface User {
id: string
name: string
email: string
}
const routes = defineRoutes([
{
method: 'POST',
path: '/users',
handler: createHandler(async ({ body }): Promise<User> => {
const user = await createUser(body)
return user
})
}
])总结
Vafast 的处理程序系统提供了：
- ✅ 类型安全的参数访问
- ✅ 自动响应类型推断
- ✅ 中间件集成支持
- ✅ 验证系统集成
- ✅ 异步操作支持
- ✅ 灵活的响应控制