# login 验证

| url      | 请求方式 | 响应内容            |
| -------- | ---- | --------------- |
| /login   | GET  | 响应登录页面          |
| /login   | POST | 对客户端提交数据进行验证    |
| /profile | GET  | 登录后界面，进入该页面需要验证 |

## 1.响应登录页面

* 判断是否已经登录，如果登录了直接跳转到个人主页

```bash
router.get("/login",function(req,rep,next){
  isLogin(req,function(err,result){
    if(err){
      next(err)
      return
    }
    if(result==0){ //cookie修改之后resule为空也需要重新登录
      rep.render("login.html")
      return
    }
    rep.redirect("/profile?"+req.cookies.account.name)
  })
})
```

## 2.用户提交数据验证

* 验证函数对用户提交的数据进行SQL查询
* 对查询结果进行判断
* 若验证成功则进行跳转页面至个人主页

```bash
router.post("/login",function(req,rep,next){
  account=req.body.name
  password=md5(req.body.password)
  authenticateAccount(account,password,function(err,result){
    if(err){
     next(err)
     return 0;
    }
    if(result!=false){
      rep.cookie("account",{name:result[0].name,password:result[0].password},{maxAge:86400000*7})
      rep.redirect("/profile?"+result[0].name)
    }
    else{
      rep.send("account or password error!")
    }
  })
})
## 验证函数，回调函数在响应用户请求的时候写好的
function authenticateAccount(account,password,callback){
  poolConnection.getConnection(function(err,connection){
    if(err){
      callback({errCode:"2",
      errMessage:"mysql connection error"  
      })
      return 0;
    }
    //verification
    sql='SELECT * FROM `user` WHERE `name`=? and `password`=?'
    connection.query(sql,[account,password],function(err,result,fields){
      if(err){
        callback(
          {
        errCode:"3",
        errMessage:"sql language with error"})
        return 0;
      }
      connection.release();
      callback(null,result)
    })
  })
}
```

## 3.个人主页访问权限

* 只有客户端cookies中存储的用户信息，能够被sql验证才能够访问该页面
* 否则跳转到登录页面，进行登录操作

```bash
router.get("/profile",function(req,rep,next){
    isLogin(req,function(err,result){
      if(err){
        next(err)
        return
      }
      if(result==0){ //cookie修改之后resule为空也需要重新登录
        rep.redirect("/login")
        return
      }
      rep.render("profile.html",{user:req.cookies.account.name})
    })
})
```

## 4.登出操作

* 当访问`/logout`路由时，直接清空客户端cookies，跳转至主页

```bash
router.get("/logout",function(req,rep,next){
  rep.clearCookie("account")
  rep.redirect("/")
})
```


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