Adding validation for list of elements in Go - validation

Question

I am new to golang
I have created a REST service using golang. I am trying to add validaiton and i am stuck in it.
I have two structs like
type Item struct {
ProductId string `json:"prodId"`
SkuId string `json:"skuId"`
Qty string `json:"qty"`
}
type AddItemsRequest struct {
Items []Item `json:"items" validate:"required"`
}
I am trying to validate AddItemsRequest
I added below code for handling this
func (r * Item) Validate() error {
return types.ErrorMap{
"prodId": validation.Validate(&r.ProductId, validation.Required, validation.Length(1, 255)),
"skuId": validation.Validate(&r.SkuId, validation.Required, validation.Length(1, 255)),
"qty": validation.Validate(&r.Qty, validation.Required, validation.Length(1, 255)),
}
}
func (r AddItemsRequest) Validate() error {
return validation.ValidateStruct(&r,
validation.Field(&r.Items, validation.Each(is.Alpha))) // Instead of Alpha how to validate each items with my Items rule
}
But I am not bale to valdiate. How can i add validation code, so that items in request is not empty or blank and only String?

Answer 1

I don't know what validation is, but I can use 'github.com/go-playground/validator' to solve this problem.
func main() {
v := validator.New()
v.RegisterValidation("mySlice", func(fl validator.FieldLevel) bool {
sli, ok := fl.Field().Interface().([]string)
if !ok {
return false
}
for i := range sli {
if len(sli[i]) < 5 {
return false
}
}
return true
}, false)
sli := []string{"hello world", "hi", "congratulation"}
err := v.Var(sli, "mySlice")
if err != nil {
panic("check error: " + err.Error())
}
print("ok")
}