add application public metadata to token transfer

Signed-off-by: Arne Rutjes <[email protected]>

Author: arner

integration/token/fungible/support.go

@@ -387,7 +387,15 @@ func TransferCash(network *integration.Infrastructure, sender *token3.NodeRefere
 	return TransferCashForTMSID(network, sender, wallet, typ, amount, receiver, auditor, nil, expectedErrorMsgs...)
 }
 
+func TransferCashWithOpts(network *integration.Infrastructure, sender *token3.NodeReference, wallet string, typ token.Type, amount uint64, receiver *token3.NodeReference, auditor *token3.NodeReference, opts []token2.TransferOption, expectedErrorMsgs ...string) string {
+	return TransferCashForTMSIDWithOpts(network, sender, wallet, typ, amount, receiver, auditor, nil, opts, expectedErrorMsgs...)
+}
+
 func TransferCashForTMSID(network *integration.Infrastructure, sender *token3.NodeReference, wallet string, typ token.Type, amount uint64, receiver *token3.NodeReference, auditor *token3.NodeReference, tmsId *token2.TMSID, expectedErrorMsgs ...string) string {
+	return TransferCashForTMSIDWithOpts(network, sender, wallet, typ, amount, receiver, auditor, nil, nil, expectedErrorMsgs...)
+}
+
+func TransferCashForTMSIDWithOpts(network *integration.Infrastructure, sender *token3.NodeReference, wallet string, typ token.Type, amount uint64, receiver *token3.NodeReference, auditor *token3.NodeReference, tmsId *token2.TMSID, opts []token2.TransferOption, expectedErrorMsgs ...string) string {
 	txidBoxed, err := network.Client(sender.ReplicaName()).CallView("transfer", common.JSONMarshall(&views.Transfer{
 		Auditor:      auditor.Id(),
 		Wallet:       wallet,
@@ -396,6 +404,7 @@ func TransferCashForTMSID(network *integration.Infrastructure, sender *token3.No
 		Recipient:    network.Identity(receiver.Id()),
 		RecipientEID: receiver.Id(),
 		TMSID:        tmsId,
+		TransferOpts: opts,
 	}))
 	if len(expectedErrorMsgs) == 0 {
 		Expect(err).NotTo(HaveOccurred())

integration/token/fungible/tests.go

@@ -26,6 +26,7 @@ import (
 	common2 "github.com/hyperledger-labs/fabric-token-sdk/integration/token/common"
 	dlog "github.com/hyperledger-labs/fabric-token-sdk/integration/token/fungible/dlogstress/support"
 	"github.com/hyperledger-labs/fabric-token-sdk/integration/token/fungible/views"
+	token4 "github.com/hyperledger-labs/fabric-token-sdk/token"
 	dlognoghv1 "github.com/hyperledger-labs/fabric-token-sdk/token/core/zkatdlog/nogh/v1/setup"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/ttx"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/ttxdb"
@@ -401,7 +402,11 @@ func TestAll(network *integration.Infrastructure, auditorId string, onRestart On
 	Restart(network, false, onRestart, alice)
 
 	t8 := time.Now()
-	TransferCash(network, alice, "", "USD", 111, bob, auditor)
+	key := fmt.Sprintf("%d", t8.UnixMilli())
+	val := []byte("public ledger data")
+	opts := []token4.TransferOption{token4.WithPublicMetadata(key, val)}
+	BobAcceptedTransactions[3:4][0].PublicMetadata = map[string][]byte{key: val}
+	TransferCashWithOpts(network, alice, "", "USD", 111, bob, auditor, opts)
 	t9 := time.Now()
 	CheckAuditedTransactions(network, auditor, AuditedTransactions[5:7], &t8, &t9)
 	CheckSpending(network, alice, "", "USD", auditor, 111)

integration/token/fungible/views/transfer.go

@@ -69,6 +69,8 @@ type Transfer struct {
 	NotAnonymous bool
 	// Metadata contains application metadata to append to the transaction
 	Metadata map[string][]byte
+	// TransferOpts contains additional options to use on the Transfer action
+	TransferOpts []token2.TransferOption
 }
 
 type TransferView struct {
@@ -140,13 +142,20 @@ func (t *TransferView) Call(context view.Context) (txID interface{}, err error)
 	// It is also possible to pass a custom token selector to the Transfer function by using the relative opt:
 	// token2.WithTokenSelector(selector).
 	span.AddEvent("append_transfer")
+
+	opts := []token2.TransferOption{
+		token2.WithTokenIDs(t.TokenIDs...),
+		token2.WithRestRecipientIdentity(t.SenderChangeRecipientData),
+	}
+	if len(t.TransferOpts) > 0 {
+		opts = append(opts, t.TransferOpts...)
+	}
 	err = tx.Transfer(
 		senderWallet,
 		t.Type,
 		[]uint64{t.Amount},
 		[]view.Identity{recipient},
-		token2.WithTokenIDs(t.TokenIDs...),
-		token2.WithRestRecipientIdentity(t.SenderChangeRecipientData),
+		opts...,
 	)
 	assert.NoError(err, "failed adding transfer action [%d:%s]", t.Amount, t.Recipient)
 

token/core/zkatdlog/nogh/v1/validator/validator.go

@@ -64,6 +64,7 @@ func New(
 		TransferUpgradeWitnessValidate,
 		TransferZKProofValidate,
 		TransferHTLCValidate,
+		TransferApplicationDataValidate,
 	}
 	transferValidators = append(transferValidators, extraValidators...)
 

token/core/zkatdlog/nogh/v1/validator/validator_transfer.go

@@ -8,6 +8,7 @@ package validator
 
 import (
 	"bytes"
+	"strings"
 	"time"
 
 	math "github.com/IBM/mathlib"
@@ -173,3 +174,15 @@ func TransferHTLCValidate(ctx *Context) error {
 	}
 	return nil
 }
+
+// TransferApplicationDataValidate accepts any metadata in the "application" namespace.
+// This gives the user of the Token SDK the option to attach public data to the token
+// transaction.
+func TransferApplicationDataValidate(ctx *Context) error {
+	for key := range ctx.TransferAction.Metadata {
+		if strings.HasPrefix(key, "application.") {
+			ctx.CountMetadataKey(key)
+		}
+	}
+	return nil
+}

token/request.go

@@ -22,6 +22,7 @@ import (
 
 const (
 	TransferMetadataPrefix = meta.TransferMetadataPrefix
+	PublicMetadataPrefix   = "application."
 )
 
 type Binder interface {
@@ -104,6 +105,14 @@ func WithTokenSelector(selector Selector) TransferOption {
 // WithTransferMetadata sets transfer action metadata
 func WithTransferMetadata(key string, value []byte) TransferOption {
 	return WithTransferAttribute(TransferMetadataPrefix+key, value)
+
+}
+
+// WithPublicMetadata adds any data to the public ledger that may be relevant to the application.
+// It is also made available to the participants as part of the TransactionRecord.
+// The transaction fails if the key already exists on the ledger. The value is not validated.
+func WithPublicMetadata(key string, value []byte) TransferOption {
+	return WithTransferAttribute(PublicMetadataPrefix+key, value)
 }
 
 // WithTokenIDs sets the tokens ids to transfer