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 go-playground/validator/v10 for request body validation.
Check the full docs and the struct tags usage here.
$ 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", "")
}
}
