vendor/gopkg.in/go-playground/validator.v9/_examples/simple/main.go

   1 package main
   2
   3 import (
   4         "fmt"
   5
   6         "gopkg.in/go-playground/validator.v9"
   7 )
   8
   9 // User contains user information
  10 type User struct {
  11         FirstName      string     `validate:"required"`
  12         LastName       string     `validate:"required"`
  13         Age            uint8      `validate:"gte=0,lte=130"`
  14         Email          string     `validate:"required,email"`
  15         FavouriteColor string     `validate:"iscolor"`                // alias for 'hexcolor|rgb|rgba|hsl|hsla'
  16         Addresses      []*Address `validate:"required,dive,required"` // a person can have a home and cottage...
  17 }
  18
  19 // Address houses a users address information
  20 type Address struct {
  21         Street string `validate:"required"`
  22         City   string `validate:"required"`
  23         Planet string `validate:"required"`
  24         Phone  string `validate:"required"`
  25 }
  26
  27 // use a single instance of Validate, it caches struct info
  28 var validate *validator.Validate
  29
  30 func main() {
  31
  32         validate = validator.New()
  33
  34         validateStruct()
  35         validateVariable()
  36 }
  37
  38 func validateStruct() {
  39
  40         address := &Address{
  41                 Street: "Eavesdown Docks",
  42                 Planet: "Persphone",
  43                 Phone:  "none",
  44         }
  45
  46         user := &User{
  47                 FirstName:      "Badger",
  48                 LastName:       "Smith",
  49                 Age:            135,
  50                 Email:          "Badger.Smith@gmail.com",
  51                 FavouriteColor: "#000-",
  52                 Addresses:      []*Address{address},
  53         }
  54
  55         // returns nil or ValidationErrors ( map[string]*FieldError )
  56         err := validate.Struct(user)
  57         if err != nil {
  58
  59                 // this check is only needed when your code could produce
  60                 // an invalid value for validation such as interface with nil
  61                 // value most including myself do not usually have code like this.
  62                 if _, ok := err.(*validator.InvalidValidationError); ok {
  63                         fmt.Println(err)
  64                         return
  65                 }
  66
  67                 for _, err := range err.(validator.ValidationErrors) {
  68
  69                         fmt.Println(err.Namespace())
  70                         fmt.Println(err.Field())
  71                         fmt.Println(err.StructNamespace()) // can differ when a custom TagNameFunc is registered or
  72                         fmt.Println(err.StructField())     // by passing alt name to ReportError like below
  73                         fmt.Println(err.Tag())
  74                         fmt.Println(err.ActualTag())
  75                         fmt.Println(err.Kind())
  76                         fmt.Println(err.Type())
  77                         fmt.Println(err.Value())
  78                         fmt.Println(err.Param())
  79                         fmt.Println()
  80                 }
  81
  82                 // from here you can create your own error messages in whatever language you wish
  83                 return
  84         }
  85
  86         // save user to database
  87 }
  88
  89 func validateVariable() {
  90
  91         myEmail := "joeybloggs.gmail.com"
  92
  93         errs := validate.Var(myEmail, "required,email")
  94
  95         if errs != nil {
  96                 fmt.Println(errs) // output: Key: "" Error:Field validation for "" failed on the "email" tag
  97                 return
  98         }
  99
 100         // email ok, move on
 101 }