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jsongomarshalling

Json error calling MarshalJSON for type json.RawMessage

I am getting following error while trying to marshal this struct

json: error calling MarshalJSON for type json.RawMessage: unexpected end of JSON input

for the object of below struct 

type Chart struct {
    ID          int             `json:"id,omitempty" db:"id"`
    Name        string          `json:"name,omitempty" db:"name"`
    Type        string          `json:"type,omitempty" db:"type"`
    DashboardID int             `json:"dashboard_id,omitempty"`
    SourceType  string          `json:"source_type,omitempty" db:"source_type"`
    Data        json.RawMessage `json:"graph_data,ommitempty"`
}

func main() {
    chart := Chart{}
    chart.ID = 1
    chart.Name = "Jishnu"
    str, err := json.Marshal(chart)
    fmt.Println(err)
}
Solution

  • Fixed by making Chart.Data a pointer

     Data        *json.RawMessage `json:"data,omitempty"`

    Go 1.8 (currently rc3 as of writing) will correctly handle Marshalling of both pointer type and non-pointer types of json.RawMessage.

    Fixing commit: https://github.com/golang/go/commit/1625da24106b610f89ff7a67a11581df95f8e234