Creating nested JSON from API call response - go

Question

How can I create a nested JSON response from a response I received from an API?
For example, I got a resp (*http.Response) from an API which I expect to be a list of objects ([{},{},{},...])
I want to create a response like so
{
total: 1234,
addresses: [{},{},{}]
}
I'm not quite sure how to deal with this. I got close as my code below returns a similar structure but my addresses section returns an escaped string like so
"[{\"access\":\"INTERNAL\",\"address\":\"1P9SnpTait5bS\"}]"
func (h *Handler) getAddresses(w http.ResponseWriter, r *http.Request) {
type Message struct {
Total int `json:total`
Addresses string `json:addresses`
}
resp, _ := h.Search(address, page, pageOffset) // *http.Response
body, _ := ioutil.ReadAll(resp.Body)
res := Message{
Total: total,
Addresses: string(body),
}
m, _ := json.Marshal(res)
w.Write(m)
}

Answer 1

You can use json.RawMessage if all you need is to pass the json along.
func (h *Handler) getAddresses(w http.ResponseWriter, r *http.Request) {
type Message struct {
Total int `json:"total"`
Addresses json.RawMessage `json:"addresses"`
}
resp, err := h.Search(address, page, pageOffset) // *http.Response
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
res := Message{
Total: total,
Addresses: json.RawMessage(body),
}
if err := json.NewEncoder(w).Encode(res); err != nil {
log.Println("failed to respond with json:", err)
}
}

Answer 2

According to your desired response format, Addresses should be defined as type []map[string]interface rather than of type string.
type Message struct {
Total int `json:total`
Addresses []map[string]interface{} `json:addresses`
}
Then you would json unmarshal the response bytes into a temporary variable of type []map[string]interface{} before assigning the temporary variable to Message.Address, and finally json marshal Message as you were doing already.
Your question currently doesn't demonstrate where total is coming from. I assume you know how to deal with total.