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

   1 package main
   2
   3 import (
   4         "fmt"
   5
   6         "gopkg.in/go-playground/validator.v9"
   7 )
   8
   9 // MyStruct ..
  10 type MyStruct struct {
  11         String string `validate:"is-awesome"`
  12 }
  13
  14 // use a single instance of Validate, it caches struct info
  15 var validate *validator.Validate
  16
  17 func main() {
  18
  19         validate = validator.New()
  20         validate.RegisterValidation("is-awesome", ValidateMyVal)
  21
  22         s := MyStruct{String: "awesome"}
  23
  24         err := validate.Struct(s)
  25         if err != nil {
  26                 fmt.Printf("Err(s):\n%+v\n", err)
  27         }
  28
  29         s.String = "not awesome"
  30         err = validate.Struct(s)
  31         if err != nil {
  32                 fmt.Printf("Err(s):\n%+v\n", err)
  33         }
  34 }
  35
  36 // ValidateMyVal implements validator.Func
  37 func ValidateMyVal(fl validator.FieldLevel) bool {
  38         return fl.Field().String() == "awesome"
  39 }