Custom how nested struct marshals about structs

[DenLilleMand]

I think this issue fits nicely into why i had to fork this library as well, i wonder if you could say something about whether you see this library support something like the PR #118 contains @fatih ? My main issue is that nested structs either get ignored, or unmarshalls all of it's children instead of adding the option to evaluate it to a single field.

I have seen suggestions to use the structs:",string" which will use the stringer interface on the struct calling the method String()

If i owned all of the structs i wanted to call the Values(interface{}) method on, it would be no problem, but if we take sql.NullString as an example the suggestion would be to do a type alias like

type SQLNullString sql.NullString

type Bar struct {
    SomeString SQLNullString `structs:",string"`
}

func (sns *SQLNullString) String() string {
    return sns.String()
}

This code has a error because sql.NullString already has a public field String so you cannot create a String() method on it's type alias.

In our fork omnioiot/structs we changed the Values() method to have something like this for the sql.NullX, in this case just the sql.NullString as an example:

if tagOpts.Has("nullstring") {
			sqlNullString, ok := val.Interface().(sql.NullString)
			if ok {
				value, err := sqlNullString.Value()
				if err == nil {
					t = append(t, value)
				} else {
					panic(err)
				}
			}
			continue
		}

I think that @FX-HAO has a PR #118, but as i commented on that PR it doesn't seem to work on structs, only maps.

[fatih]

Hi,

Unfortunately, I'm archiving this project and will no longer maintaining it. For more information, please read my blog post: Taking an indefinite sabbatical from my projects.

Thanks for the feedback and contribution.