How to convert an array with different things to JSON?

Question

go

There is an array in which there will be all sorts of errors. Since the errors are different, the array type is "interface{}". When the errors are collected, they should be sent to the user in JSON. Here is the problem with this. json.Marshal doesn't return anything. How can an array with errors be encoded into JSON?

The way is this:
1. first the errors themselves

type ecError struct { // от него наследуются все ошибки
  statusCode int
  errorCode  string
  issuers    []string
  message    string
}
type ecEUnknown struct {
  ecError
}
type ecEValidationMinmax struct {
  ecError
  min int
  max int
}

2. create, call, and get errors:

var ec = servus.Server.NewErrorCollector()
  var issuers [] string
  issuers = append(issuers, "ModelsBoot")
  servus.Server.AddEValidationMinmax(&ec, issuers, "hello", 1,2)
  servus.Server.AddEUnknown(&ec, issuers, "hello")
  servus.Server.GetErrors(&ec)

2.1 example of a function that adds an error:

func (e serverT) AddEUnknown(ec *errorCollectorT, issuers []string, message string) {
  _error := ecEUnknown{
    ecError{statusCode: 500, errorCode: "E_UNKNOWN", issuers: issuers, message: message},
  }
  ec.errorsArray = append(ec.errorsArray, _error)
}

3. piece from GetErrors:

var bytes, err = json.Marshal(ec.errorsArray)
  if err != nil {
    log.Println("json поломался")
  }
  log.Println(ec.errorsArray)
  log.Println(string(bytes))

4. Conclusion:

2021/08/12 15:25:50 [{{400 E_VALIDATION_MINMAX [ModelsBoot] hello} 1 2} {{500 E_UNKNOWN [ModelsBoot] hello}}]
2021/08/12 15:25:50 [{},{}]

Answer 1

You have fields in structures that are not exportable, i.e. everything starts with small letters.
JSON cannot export such fields.
Just rename it and it will work.
And it’s better to make the structures also with a big one, so that in the end it would be like this.

type EcError struct { // от него наследуются все ошибки
  StatusCode int
  ErrorCode  string
  Issuers    []string
  Message    string
}
type EcEUnknown struct {
  EcError
}
type EcEValidationMinmax struct {
  EcError
  Min int
  Max int
}