在Golang中反序列化模式字段

Question

I am writing golang struct, which are compatible with some json structure. However, those most of the fields are know, there will be few fields following some specific patterns(like "x-{randomName}") in the json definition, which I also want to get deserialized to a certain field as map[string]interface{} as well.

Is there any descent way to achieve it?

Answer 1

It's less efficient, but you could unmarshal twice to avoid manually mapping the fields. Once to put all the properly tagged fields into the struct, and then again into a map[string]interface{} to get everything else. If you don't care about the duplicate fields, you don't even need to filter the second map.

You can even do this in an UnmarshalJSONmethod to automatically populate the struct

type S struct {
    A   string `json:"a"`
    B   string `json:"b"`
    All map[string]interface{}
}

func (s *S) UnmarshalJSON(b []byte) error {
    // create a new type to hide the UnmarshalJSON method
    // otherwise we'll recurse indefinitely.
    type ss S

    err := json.Unmarshal(b, (*ss)(s))
    if err != nil {
        return err
    }
    // now unmarshal again into the All map
    err = json.Unmarshal(b, &s.All)
    if err != nil {
        return err
    }

    return nil
}

http://play.golang.org/p/VBVlRjNlHy