MarshalJSON() output encrypted json

[Gert]

https://play.golang.org/p/6qKkJhVsnU1

type Payload struct{}

func (p Payload) MarshalJSON() ([]byte, error) {

return []byte("my custom encryption stuf"), nil

}

func main() {

p := Payload{}

j, err := json.Marshal(p)

if err != nil {

fmt.Println(err)

}

fmt.Println(string(j))

}

json: error calling MarshalJSON for type main.Payload: invalid character 'm' looking for beginning of value

How do you skip the check from json.Marshal and just return the []byte directly whatever they are?

[Axel Wagner]

`MarshalJSON` needs to output a valid JSON value, according to the interface. If you don't need the result to be valid JSON, then don't use encoding/json. If you want to use JSON to use it as part of a larger value, you could output a JSON string (but you should familiarize yourself with what a JSON string can and can't contain - e.g. if your encrypted bytes contain quotes, that'll be problematic).

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[Gert Cuykens]

Thanks, Which should I use instead then? The reason I use it is so I
can easily switch between regular json payloads for debugging and
encrypted/signed urlencode payloads

[Dan Kortschak]

MarshalText?

[Gert Cuykens]

Ok thanks, I will try that but don't think it will be elegant for
turning on and off plain json in a code base, because I have to change
every json.Marshal and json.Umarshal

[Dan Kortschak]

It depends what you want to get. json.Marshal picks up
encoding.TextEncoder and Unmarshal, TextDecoder. It will wrap the
marshaled text into a quoted json string and then pull it out again
when you deserialise. From the json.Marshal docs

```
If no MarshalJSON method is present but the value implements
encoding.TextMarshaler instead, Marshal calls its MarshalText method
and encodes the result as a JSON string.
```

[Lutz Horn]

The string

"my custom encryption stuff"

is not valid JSON. Why does your type implement MarshalJSON if it does not produce JSON?

Lutz

---

Von: Gert
Gesendet: ‎27.‎12.‎2019 07:55
An: golang-nuts
Betreff: [go-nuts] MarshalJSON() output encrypted json

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