取消对JSON输入的意外结束，同时对结构进行了编组

Question

Could you help me to understand why I'm always getting the error unexpected end of JSON input while trying to unmarshal the following json to the LimitOrder struct?

P.S.: if I use map[string]json.RawMessage instead of LimitOrder struct I'm able to execute the unmarshal.

{
  "response_data": {
    "order": {
      "order_id": 3,
      "coin_pair": "BRLBTC",
      "order_type": 1,
      "status": 4,
      "has_fills": true,
      "quantity": "1.00000000",
      "limit_price": "900.00000",
      "executed_quantity": "1.00000000",
      "executed_price_avg": "900.00000",
      "fee": "0.00300000",
      "created_timestamp": "1453835329",
      "updated_timestamp": "1453835329",
      "operations": [
        {
          "operation_id": 1,
          "quantity": "1.00000000",
          "price": "900.00000",
          "fee_rate": "0.30",
          "executed_timestamp": "1453835329"
        }
      ]
    }
  },
  "status_code": 100,
  "server_unix_timestamp": "1453835329"
}

LimitOrder struct

type LimitOrder struct {
  OrderId int `json:"order_id"`
  CoinPair string `json:"coin_pair"`
  OrderType int `json:"order_type"`
  Status int `json:"status"`
  HasFills bool `json:"has_fills"`
  Quantity float64 `json:"quantity,string"`
  LimitPrice float64 `json:"limit_price,string"`
  ExecutedQuantity float64 `json:"executed_quantity,string"`
  ExecutedPriceAvg float64 `json:"executed_price_avg,string"`
  Fee float64 `json:"fee,string"`
  Operations []*Operation `json:"operations"`
  CreatedTimestamp string `json:"created_timestamp"`
  UpdatedTimestamp string `json:"updated_timestamp"`
}

and this is how I'm trying to unmarshal it

func (limitOrder *LimitOrder) UnmarshalJSON(buf []byte) error {

  tmp := make(map[string]json.RawMessage)
  if err := json.Unmarshal(buf, &tmp); err != nil {
    return err
  }

  tmp2 := make(map[string]json.RawMessage)

  if err := json.Unmarshal(tmp["response_data"], &tmp2); err != nil {
    return err
  }

  if err := json.Unmarshal(tmp2["order"], limitOrder); err != nil {
    return err
  }

  return nil
}

Answer 1

I found some help on golang-nuts group. You can check the answer here https://groups.google.com/forum/#!topic/golang-nuts/SZXBcXgUoo0. To make a long story short, the problem was with my structures, I've built structures only for a small piece of the whole json, so I fixed it building structures for the whole json response.