1package identity
 2
 3import (
 4	"encoding/json"
 5	"fmt"
 6)
 7
 8// Custom unmarshaling function to allow package user to delegate
 9// the decoding of an Identity and distinguish between an Identity
10// and a Bare.
11//
12// If the given message has a "id" field, it's considered being a proper Identity.
13func UnmarshalJSON(raw json.RawMessage) (Interface, error) {
14	aux := &IdentityStub{}
15
16	// First try to decode and load as a normal Identity
17	err := json.Unmarshal(raw, &aux)
18	if err == nil && aux.Id() != "" {
19		return aux, nil
20	}
21
22	// abort if we have an error other than the wrong type
23	if _, ok := err.(*json.UnmarshalTypeError); err != nil && !ok {
24		return nil, err
25	}
26
27	return nil, fmt.Errorf("unknown identity type")
28}