Iris, wisely, not features a builtin data validation. However, it does allow you to attach a validator which will automatically called on methods like Context.ReadJSON, ReadXML.... In this example we will learn how to use the for request body validation.
Check the full docs and the struct tags usage .
$ go get github.com/go-playground/validator/v10@latest
Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set json:"fieldname".
package main
import (
"fmt"
"github.com/kataras/iris/v12"
"github.com/go-playground/validator/v10"
)
// User contains user information.
type User struct {
FirstName string `json:"fname"`
LastName string `json:"lname"`
Age uint8 `json:"age" validate:"gte=0,lte=130"`
Email string `json:"email" validate:"required,email"`
FavouriteColor string `json:"favColor" validate:"hexcolor|rgb|rgba"`
Addresses []*Address `json:"addresses" validate:"required,dive,required"`
}
// Address houses a users address information.
type Address struct {
Street string `json:"street" validate:"required"`
City string `json:"city" validate:"required"`
Planet string `json:"planet" validate:"required"`
Phone string `json:"phone" validate:"required"`
}
func main() {
// Use a single instance of Validate, it caches struct info.
v := validator.New()
// Register a custom struct validation for 'User'
// NOTE: only have to register a non-pointer type for 'User', validator
// internally dereferences during it's type checks.
v.RegisterStructValidation(UserStructLevelValidation, User{})
app := iris.New()
// Register the validator to the Iris Application.
app.Validator = v
app.Post("/user", func(ctx iris.Context) {
var user User
// Returns InvalidValidationError for bad validation input,
// nil or ValidationErrors ( []FieldError )
err := ctx.ReadJSON(&user)
if err != nil {
// This check is only needed when your code could produce
// an invalid value for validation such as interface with nil
// value most including myself do not usually have code like this.
if _, ok := err.(*validator.InvalidValidationError); ok {
ctx.StatusCode(iris.StatusInternalServerError)
ctx.WriteString(err.Error())
return
}
ctx.StatusCode(iris.StatusBadRequest)
for _, err := range err.(validator.ValidationErrors) {
fmt.Println()
fmt.Println(err.Namespace())
fmt.Println(err.Field())
fmt.Println(err.StructNamespace())
fmt.Println(err.StructField())
fmt.Println(err.Tag())
fmt.Println(err.ActualTag())
fmt.Println(err.Kind())
fmt.Println(err.Type())
fmt.Println(err.Value())
fmt.Println(err.Param())
fmt.Println()
}
return
}
// [save user to database...]
})
app.Listen(":8080")
}
func UserStructLevelValidation(sl validator.StructLevel) {
user := sl.Current().Interface().(User)
if len(user.FirstName) == 0 && len(user.LastName) == 0 {
sl.ReportError(user.FirstName, "FirstName", "fname", "fnameorlname", "")
sl.ReportError(user.LastName, "LastName", "lname", "fnameorlname", "")
}
}
