Detailed explanation of the binding and msg structure label examples in the gorm structure

type LoginForm struct {
    Username string `json:"username" binding:"required" msg:"Username cannot be empty"`
    Password string `json:"password" binding:"required,min=6" msg:"Password cannot be empty and has at least length6Bit"`
    Age      int    `json:"age" binding:"required,gte=18" msg:"Age must be greater than or equal to18age"`
    Email    string `json:"email" binding:"required,email" msg:"Please enter a valid email address"`
}

func Login(c *) {
    var form LoginForm
    if err := (&form); err != nil {
        (400, {"error": ()})
        return
    }
    // Handle login logic...}

type User struct {
    // required: Required    Name string `binding:"required"`
    // min,max: string length or number range    Password string `binding:"min=6,max=20"`
    // email: Email format    Email string `binding:"email"`
    // oneof: Enumeration value    Role string `binding:"oneof=admin user guest"`
    // gte,lte: greater than or equal to, less than or equal to    Age int `binding:"gte=18,lte=100"`
    // url: URL format    Website string `binding:"url"`
    // Regular expression    Phone string `binding:"required,regexp=^1[3-9]\\d{9}$"`
}

type RegisterForm struct {
    Password string `binding:"required,CustomPassword"`
    Phone    string `binding:"required,CustomPhone"`
}
func customValidator() {
    if v, ok := ().(*); ok {
        // Register a custom validator        ("CustomPassword", ValidatePassword)
        ("CustomPhone", ValidatePhone)
    }
}
func ValidatePassword(fl ) bool {
    password := ().String()
    // Custom password verification logic    return len(password) >= 8
}

type CreateUserForm struct {
    Username string `json:"username" binding:"required" msg:"Username cannot be empty"`
    Password string `json:"password" binding:"required,min=6" msg:"Minimum password length6Bit"`
}
// Helper function for handling error messagesfunc getValidMsg(err error, obj interface{}) string {
    // Get struct type by reflection    getObj := (obj)
    // If it is a pointer, get its base type    if () ==  {
        getObj = ()
    }
    // Convert error message to validator error    if errs, ok := err.(); ok {
        // traverse every error        for _, e := range errs {
            // Get the corresponding field            if f, exist := (()); exist {
                // Get the msg tag content                msg := ("msg")
                if msg != "" {
                    return msg
                }
            }
        }
    }
    return ()
}

func CreateUser(c *) {
    var form CreateUserForm
    if err := (&form); err != nil {
        // Get custom error message        errMsg := getValidMsg(err, form)
        (400, {"error": errMsg})
        return
    }
    // Handle business logic...}

type Product struct {
    // Multiple verification rules are separated by commas    Name  string `binding:"required,min=2,max=50" msg:"The product name must be in2-50between"`
    Price float64 `binding:"required,gte=0" msg:"The price must be greater than or equal to0"`
    // Condition verification: Description is required when Status is "active".    Status      string `binding:"required,oneof=active inactive" msg:"The status must be active or inactive"`
    Description string `binding:"required_if=Status active" msg:"When the status isactivehour，Required description"`
}

type ChangePassword struct {
    Password        string `binding:"required" msg:"Password cannot be empty"`
    ConfirmPassword string `binding:"required,eqfield=Password" msg:"The passwords entered twice are inconsistent"`
}

func InitValidator() {
    // Register a validator    if v, ok := ().(*); ok {
        // Register a custom validator        ("custom_validation", CustomValidationFunc)
        // Register a custom error message translator        (v, trans)
    }
}