CODEWITHSUNDEEP
go
Seth Archer Brown
Seth Archer Brown

Reputation: 1191

Arbitrary JSON data structure in go

I'm building an http api and every one of my handlers returns JSON data, so I built a wrapper function that handles the JSON marshalling and http response (I've included the relevant section from the wrapper as well as one of the sample handlers below).

What is the best way to pass arbitrarily nested structs (the structs also contain arbitrary types/number of fields). Right now I've settled on a map with string keys and interface{} values. This works, but is this the most idiomatic go way to do this?

result := make(map[string]interface{})
customerList(httpRequest, &result)

j, err := json.Marshal(result)
if err != nil {
    log.Println(err)
    errs := `{"error": "json.Marshal failed"}`
    w.Write([]byte(errs))
    return
}
w.Write(j)


func customerList(req *http.Request, result *map[string]interface{}) {
    data, err := database.RecentFiftyCustomers()
    if err != nil {
        (*result)["error"] = stringifyErr(err, "customerList()")
        return
    }

    (*result)["customers"] = data//data is a slice of arbitrarily nested structs
}

Upvotes: 1

Views: 2010

Answers (1)

Volker
Volker

Reputation: 42413

If you do not know in advance what types, what structure and which nesting you get, there is no option but to decode it into something generic like map[string]interface{}. So nothing "idiomatic" or "non-idiomatic" here.

(Personally I'd try to somehow fix the structs and not have "arbitrary" nestings, and combinations.)

Upvotes: 1

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