valid.go

package valid

import (
	"reflect"
)

const tagName = "valid"

func IsZero(x interface{}) bool {
	return reflect.DeepEqual(x, reflect.Zero(reflect.TypeOf(x)).Interface())
}

func Valid(obj interface{}) bool {
	ok := true
	original := reflect.ValueOf(obj)
	validRecursive(original, &ok)
	return ok
}

func validRecursive(original reflect.Value, ok *bool) {
	switch original.Kind() {
	case reflect.Ptr:
		originalValue := original.Elem()
		// Check if the pointer is nil
		if !originalValue.IsValid() {
			*ok = false
			return
		}
		validRecursive(originalValue, ok)
	case reflect.Interface:
		originalValue := original.Elem()
		validRecursive(originalValue, ok)

	case reflect.Struct:
		for i := 0; i < original.NumField(); i++ {
			tag := original.Type().Field(i).Tag.Get(tagName)
			// Skip if tag is not defined or ignored
			if tag == "" || tag == "-" {
				continue
			}
			validRecursive(original.Field(i), ok)
		}

	case reflect.Slice:
		for i := 0; i < original.Len(); i++ {
			validRecursive(original.Index(i), ok)
		}

	case reflect.Map:
		for _, key := range original.MapKeys() {
			originalValue := original.MapIndex(key)
			validRecursive(originalValue, ok)
		}

	// We don't check the bool value
	case reflect.Bool:
		break
	// And everything else will simply be taken from the original
	default:
		if IsZero(original.Interface()) {
			*ok = false
			return
		}
	}
}