parse subject position

Author: ilya-korotya

json-ld/parser.go

@@ -95,7 +95,16 @@ func (p Parser) ParseClaim(credential *verifiable.Iden3Credential, schemaBytes [
 		if err != nil {
 			return nil, err
 		}
-		claim.SetIndexID(id)
+
+		switch credential.SubjectPosition {
+		case "", utils.SubjectPositionIndex:
+			claim.SetIndexID(id)
+		case utils.SubjectPositionValue:
+			claim.SetValueID(id)
+		default:
+			return nil, errors.New("unknown subject position")
+		}
+
 	}
 
 	return claim, nil

json/parser.go

@@ -64,7 +64,15 @@ func (s Parser) ParseClaim(credential *verifiable.Iden3Credential, schemaBytes [
 		if err != nil {
 			return nil, err
 		}
-		claim.SetIndexID(id)
+
+		switch credential.SubjectPosition {
+		case "", utils.SubjectPositionIndex:
+			claim.SetIndexID(id)
+		case utils.SubjectPositionValue:
+			claim.SetValueID(id)
+		default:
+			return nil, errors.New("unknown subject position")
+		}
 	}
 
 	return claim, nil

utils/claims.go

@@ -11,6 +11,13 @@ import (
 	"github.com/pkg/errors"
 )
 
+const (
+	// SubjectPositionIndex save subject in index part of claim. By default.
+	SubjectPositionIndex = "index"
+	// SubjectPositionValue save subject in value part of claim.
+	SubjectPositionValue = "value"
+)
+
 var q *big.Int
 
 //nolint //reason - needed