I am currently using reflect to get fields from a struct and return back the values as a slice of interface values. I've come across an issue with unexported fields, I want to be able to grab the unexported values and return them, along with the exported fields. When I try to get the values from my unexported fields I get the following error:
reflect.Value.Interface: cannot return value obtained from unexported field or method [recovered]
I have been using https://github.com/fatih/structs as a base for my code and want it to work with unexported fields.
// Values returns us the structs values ready to be converted into our repeatable digest.
func (s *StructWrapper) Values() []interface{} {
fields := s.structFields()
var t []interface{}
for _, field := range fields {
val := s.value.FieldByName(field.Name)
if IsStruct(val.Interface()) {
// look out for embedded structs, and convert them to a
// []interface{} to be added to the final values slice
t = append(t, Values(val.Interface())...)
} else {
t = append(t, val.Interface())
}
}
return t
}
// Values converts the given struct to a []interface{}. For more info refer to
// StructWrapper types Values() method. It panics if s's kind is not struct.
func Values(s interface{}) []interface{} {
return New(s).Values()
}
// New returns a new *StructWrapper with the struct s. It panics if the s's kind is
// not struct.
func New(s interface{}) *StructWrapper {
return &StructWrapper{
raw: s,
value: strctVal(s),
}
}
func strctVal(s interface{}) reflect.Value {
v := reflect.ValueOf(s)
// if pointer get the underlying element≤
for v.Kind() == reflect.Ptr {
v = v.Elem()
}
if v.Kind() != reflect.Struct {
panic("not struct")
}
return v
}
// structFields returns the exported struct fields for a given s struct. This
// is a convenient helper method to avoid duplicate code in some of the
// functions.
func (s *StructWrapper) structFields() []reflect.StructField {
t := s.value.Type()
var f []reflect.StructField
for i := 0; i < t.NumField(); i++ {
field := t.Field(i)
f = append(f, field)
}
return f
}
I am getting the error when I call val.Interface()
in my values method on an unexported field. Is there a way around this with reflect so it returns all exported and unexported field values?
Is there a way around this with reflect so it returns all exported and unexported field values?
No.
That would defeat the purpose of being unexported.