示例02 云函数编写与触发

示例02 云函数编写与触发

对应教程：第 2 章 · 云函数：Serverless 后端逻辑核心

1. 基础云函数（事件驱动）

// functions/hello/index.js
exports.main = async (event, context) => {
  const { name = 'World' } = event
  return {
    message: `Hello, ${name}!`,
    timestamp: Date.now()
  }
}
​

客户端调用：

const res = await app.callFunction({
  name: 'hello',
  data: { name: 'CloudBase' }
})
console.log(res.result) // { message: 'Hello, CloudBase!', timestamp: ... }
​

2. HTTP 触发云函数

// functions/api/index.js
exports.main = async (event, context) => {
  const { httpMethod, path } = event
  
  if (httpMethod === 'GET' && path === '/api/status') {
    return {
      statusCode: 200,
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ status: 'ok', version: '1.0.0' })
    }
  }
  
  return { statusCode: 404, body: 'Not Found' }
}
​

3. 定时触发云函数

// functions/cleanup/index.js
const cloud = require('@cloudbase/node-sdk')
const app = cloud.init({ env: cloud.SYMBOL_CURRENT_ENV })
const db = app.database()

exports.main = async (event, context) => {
  // 清理 7 天前的过期数据
  const sevenDaysAgo = Date.now() - 7 * 24 * 3600 * 1000
  
  const { deleted } = await db.collection('logs')
    .where({ createdAt: db.command.lt(sevenDaysAgo) })
    .remove()
  
  return { deletedCount: deleted }
}
​

定时触发器配置（cloudbaserc.json）：

{
  "triggers": [{
    "name": "dailyCleanup",
    "type": "timer",
    "config": "0 0 2 * * * *"
  }]
}
​

4. 云函数中调用其他云资源

// functions/order/index.js
const cloud = require('@cloudbase/node-sdk')
const app = cloud.init({ env: cloud.SYMBOL_CURRENT_ENV })
const db = app.database()
const storage = app.storage()

exports.main = async (event, context) => {
  const { orderId } = event
  
  // 1. 查数据库获取订单
  const { data: order } = await db.collection('orders').doc(orderId).get()
  
  // 2. 从云存储下载附件
  const fileRes = await storage.downloadFile({
    fileID: order.attachmentFileID
  })
  
  // 3. 更新订单状态
  await db.collection('orders').doc(orderId).update({
    status: 'processing',
    updatedAt: db.serverDate()
  })
  
  return { success: true, order }
}
​