简单了解小程序+node梳理登陆流程

wx.login({
success: ([code]) => {
// 发送 code 到后台换取 openId, sessionKey, unionId
}
})

// 请求方法
const request = require('request')
const url = https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code
module.exports = {
async getSession(code) {
return new Promise((resolve, reject) => {
request(url,{
method: 'GET',
json: true
},
(error, res, body) => {
if (error) {
reject(error)
} else {
if (body.errcode) {
reject(new Error(body.errmsg))
} else {
resolve(body)
}
}
}
)
})
}
}

const crypto = require('crypto')
const secret = '2019_06'
const algorithm = 'aes-256-cbc'
function encode(id) {
const encoder = crypto.createCipher(algorithm, secret)
const str = [id, Date.now(), '2019'].join('|')
let encrypted = encoder.update(str, 'utf8', 'hex')
encrypted += encoder.final('hex')
return encrypted
}
function decode(str) {
const decoder = crypto.createDecipher(algorithm, secret)
let decoded = decoder.update(str, 'hex', 'utf8')
decoded += decoder.final('utf8')
const arr = decoded.split('|')
return {
id: arr[0],
timespan: parseInt(arr[1])
}
}
module.exports = {
encode,
decode
}

const { encode } = require('./lib/crypto')
const jsonMine = 'application/json'
const now = Date.now()
function handle(ctx, data, code = 0, message = 'success') {
ctx.type = jsonMine
ctx.body = {
code,
data,
message
}
}
router.get('/login', async (ctx, next) => {
const { code } = ctx.request.query
const session = await login(code)
if (session) {
const { session_key, openid } = session
// 查找数据库中是否已经存有openid，如果 hasOpenid 为null说明是新用户
const hasOpenid = await User.findByPk(openid)
if(!hasOpenid){
// 数据库存储openid,时间戳
User.create({openid,timespan:Date.now()})
}
handle(ctx, { token: encode(openid) })
} else {
throw new Error('登陆失败')
}
})

import { LOGIN_TOKEN } from '../../utils/localStorage'
// 拿到token存储到客户端
wx.setStorageSync(LOGIN_TOKEN, token)

header: {
'x-session': wx.getStorageSync(LOGIN_TOKEN)
},

module.exports = async function(ctx, next) {
const sessionKey = ctx.get('x-session')
const { id, timespan } = decode(sessionKey)
// 查找数据库中是否存在该 openid，返回是一个数组，如果不存在则返回[]
const targetList = await getOpenid(id)
if (targetList.length > 0) {
// 如果超过设定的过期时间，标记isExpired字段为登陆过期
const oneHour = 1000 * 60 * 60 * 24
if (Date.now() - timespan > oneHour) {
ctx.state.isExpired = true
// 跟前台约定，如果code=2说明登陆过期跳登陆页面
handle(ctx, '', 2, '登陆过期')
} else {
handle(ctx, '', 0, '登陆成功')
}
} else {
// 通过ctx.throw可以直接抛出错误
ctx.throw(401, '登陆失败')
}