G01学习笔记-8

阅读位置10.8

知识点

1、 gorm 迁移

1.1 gorm.DB.AutoMigrate ()

// 自动迁移
db.AutoMigrate(
    &user.User{},
    &article.Article{},
)

1.2 字段标签

 //User 用户模型 
 type User struct { 
     models.BaseModel 
     Name string `gorm:"column:name;type:varchar(255);not null;unique"` 
     Email string `gorm:"column:email;type:varchar(255);default:NULL;unique;"`
     Password string `gorm:"column:password;type:varchar(255)"` 
 }

上面使用 Struct 元素类型后面跟着 gorm: 开头的就是 GORM 提供的字段标签。告知 GORM 在迁移时，设置数据库字段。
声明 GORM 数据模型时，字段标签是可选的，GORM 支持以下：（注：名大小写不敏感，但建议使用 camelCase 风格）

gorm迁移文档： gorm.io/docs/migration.html#conten...

2、 表单验证

比较知名的有 asaskevich/govalidator 和 thedevsaddam/govalidator

后面基于笔记thedevsaddam/govalidator

2.1 定义表单规则

rules := govalidator.MapData{
        "name":             []string{"required", "alpha_num", "between:3,20"},
        "email":            []string{"required", "min:4", "max:30", "email"},
        "password":         []string{"required", "min:6"},
        "password_confirm": []string{"required"},
}

常用的规则

全部规则：github.com/thedevsaddam/govalidato...

2.2 定义错误信息

// 定制错误消息
    messages := govalidator.MapData{
        "name": []string{
            "required:用户名为必填项",
            "alpha_num:格式错误，只允许数字和英文",
            "between:用户名长度需在 3~20 之间",
        },
        "email": []string{
            "required:Email 为必填项",
            "min:Email 长度需大于 4",
            "max:Email 长度需小于 30",
            "email:Email 格式不正确，请提供有效的邮箱地址",
        },
        "password": []string{
            "required:密码为必填项",
            "min:长度需大于 6",
        },
        "password_confirm": []string{
            "required:确认密码框为必填项",
        },
    }

2.3 配置

type User struct { 
    models.BaseModel 
    Name string `gorm:"type:varchar(255);not null;unique" valid:"name"` 
    Email string `gorm:"type:varchar(255);unique;" valid:"email"` 
    Password string `gorm:"type:varchar(255)" valid:"password"` 
    // gorm:"-" —— 设置 GORM 在读写时略过此字段，仅用于表单验证
    PasswordConfirm string `gorm:"-" valid:"password_confirm"` 
}
// 根据 valid 标识的进行对应规则的校验
opts := govalidator.Options{
        Data:          &_user,
        Rules:         rules,
        TagIdentifier: "valid", // Struct 标签标识符 
        Messages:      messages,
    }

2.4 校验

 // 开始验证
 errs := govalidator.New(opts).ValidateStruct()

2.5 自定义校验规则

govalidator.AddCustomRule()

// 此方法会在初始化时执行
func init() {
    // not_exists:users,email
    govalidator.AddCustomRule("not_exists", func(field string, rule string, message string, value interface{}) error {
        rng := strings.Split(strings.TrimPrefix(rule, "not_exists:"), ",")

        tableName := rng[0]
        dbFiled := rng[1]
        val := value.(string)

        var count int64
        model.DB.Table(tableName).Where(dbFiled+" = ?", val).Count(&count)

        if count != 0 {

            if message != "" {
                return errors.New(message)
            }

            return fmt.Errorf("%v 已被占用", val)
        }
        return nil
    })
}

fmt.Errorf 函数。先调用 fmt.Sprintf 函数，得到确切的错误信息；再调用 errors.New 函数，得到包含该错误信息的 error 类型值，最后返回该值。

3、登录和会话控制

使用 gorilla/sessions 来做会话管理

gorilla/sessions provides cookie and filesystem sessions and infrastructure for custom session backends.

    import (
        "net/http"
        "github.com/gorilla/sessions"
    )
    // Note: Don't store your key in your source code. Pass it via an
    // environmental variable, or flag (or both), and don't accidentally commit it
    // alongside your code. Ensure your key is sufficiently random - i.e. use Go's
    // crypto/rand or securecookie.GenerateRandomKey(32) and persist the result.
    var store = sessions.NewCookieStore([]byte(os.Getenv("SESSION_KEY")))

    func MyHandler(w http.ResponseWriter, r *http.Request) {
        // Get a session. We're ignoring the error resulted from decoding an
        // existing session: Get() always returns a session, even if empty.
        session, _ := store.Get(r, "session-name")
        // Set some session values.
        session.Values["foo"] = "bar"
        session.Values[42] = 43
        // Save it before we write to the response/return from the handler.
        err := session.Save(r, w)
        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
            return
        }
    }

封装

package session

import (
    "goblog/pkg/logger"
    "net/http"

    "github.com/gorilla/sessions"
)

// Store gorilla sessions 的存储库
var Store = sessions.NewCookieStore([]byte("33446a9dcf9ea060a0a6532b166da32f304af0de"))

// Session 当前会话
var Session *sessions.Session

// Request 用以获取会话
var Request *http.Request

// Response 用以写入会话
var Response http.ResponseWriter

// StartSession 初始化会话，在中间件中调用
func StartSession(w http.ResponseWriter, r *http.Request) {
    var err error

    // Store.Get() 的第二个参数是 Cookie 的名称
    // gorilla/sessions 支持多会话，本项目我们只使用单一会话即可
    Session, err = Store.Get(r, "goblog-session")
    logger.LogError(err)

    Request = r
    Response = w
}

// Put 写入键值对应的会话数据
func Put(key string, value interface{}) {
    Session.Values[key] = value
    Save()
}

// Get 获取会话数据，获取数据时请做类型检测
func Get(key string) interface{} {
    return Session.Values[key]
}

// Forget 删除某个会话项
func Forget(key string) {
    delete(Session.Values, key)
    Save()
}

// Flush 删除当前会话
func Flush() {
    Session.Options.MaxAge = -1
    Save()
}

// Save 保持会话
func Save() {
    // 非 HTTPS 的链接无法使用 Secure 和 HttpOnly，浏览器会报错
    // Session.Options.Secure = true
    // Session.Options.HttpOnly = true
    err := Session.Save(Request, Response)
    logger.LogError(err)
}

第三方的存储器

例：redis
go get gopkg.in/boj/redistore.v1

Example

// Fetch new store.
store, err := NewRediStore(10, "tcp", ":6379", "", []byte("secret-key"))
if err != nil {
    panic(err)
}
defer store.Close()

// Get a session.
session, err = store.Get(req, "session-key")
if err != nil {
    log.Error(err.Error())
}

// Add a value.
session.Values["foo"] = "bar"

// Save.
if err = sessions.Save(req, rsp); err != nil {
    t.Fatalf("Error saving session: %v", err)
}

// Delete session.
session.Options.MaxAge = -1
if err = sessions.Save(req, rsp); err != nil {
    t.Fatalf("Error saving session: %v", err)
}

// Change session storage configuration for MaxAge = 10 days.
store.SetMaxAge(10 * 24 * 3600)

本作品采用《CC 协议》，转载必须注明作者和本文链接