erc721 tokenURI(): return NFT uri+name+description

packages/isc/irc27nft.go

@@ -5,11 +5,16 @@ import "encoding/json"
 // IRC27NFTMetadata represents an NFT metadata according to IRC27.
 // See: https://github.com/iotaledger/tips/blob/main/tips/TIP-0027/tip-0027.md
 type IRC27NFTMetadata struct {
-	Standard string `json:"standard"`
-	Version  string `json:"version"`
-	MIMEType string `json:"type"`
-	URI      string `json:"uri"`
-	Name     string `json:"name"`
+	Standard       string             `json:"standard"`
+	Version        string             `json:"version"`
+	MIMEType       string             `json:"type"`
+	URI            string             `json:"uri"`
+	Name           string             `json:"name"`
+	CollectionName string             `json:"collectionName,omitempty"`
+	Royalties      map[string]float32 `json:"royalties,omitempty"`
+	IssuerName     string             `json:"issuerName,omitempty"`
+	Description    string             `json:"description,omitempty"`
+	Attributes     *json.RawMessage   `json:"attributes,omitempty"`
 }
 
 func NewIRC27NFTMetadata(mimeType, uri, name string) *IRC27NFTMetadata {

packages/vm/core/evm/evmimpl/iscmagic_sandbox_view.go

@@ -16,6 +16,7 @@ import (
 	"github.com/iotaledger/wasp/packages/parameters"
 	"github.com/iotaledger/wasp/packages/vm/core/accounts"
 	"github.com/iotaledger/wasp/packages/vm/core/errors/coreerrors"
+	"github.com/iotaledger/wasp/packages/vm/core/evm"
 	"github.com/iotaledger/wasp/packages/vm/core/evm/iscmagic"
 )
 
@@ -39,6 +40,9 @@ func (h *magicContractHandler) GetNFTData(nftID iscmagic.NFTID) iscmagic.ISCNFT
 func (h *magicContractHandler) GetIRC27NFTData(nftID iscmagic.NFTID) iscmagic.IRC27NFT {
 	nft := h.ctx.GetNFTData(nftID.Unwrap())
 	metadata, err := isc.IRC27NFTMetadataFromBytes(nft.Metadata)
+	// This hack is so that the ERC721 tokenURI view function returns the NFT name and description
+	// for explorers
+	metadata.URI = evm.EncodePackedNFTURI(metadata)
 	h.ctx.RequireNoError(err)
 	return iscmagic.IRC27NFT{
 		Nft:      iscmagic.WrapISCNFT(nft),

packages/vm/core/evm/evmtest/evm_test.go

@@ -1103,7 +1103,11 @@ func TestERC721NFTCollection(t *testing.T) {
 	{
 		var uri string
 		erc721.callView("tokenURI", []any{iscmagic.WrapNFTID(nft.ID).TokenID()}, &uri)
-		require.EqualValues(t, nftMetadatas[0].URI, uri)
+		p, err := evm.DecodePackedNFTURI(uri)
+		require.NoError(t, err)
+		require.EqualValues(t, nftMetadatas[0].URI, p.Image)
+		require.EqualValues(t, nftMetadatas[0].Name, p.Name)
+		require.EqualValues(t, nftMetadatas[0].Description, p.Description)
 	}
 }
 

packages/vm/core/evm/iscmagic/ISCSandbox.sol

@@ -109,6 +109,12 @@ interface ISCSandbox {
     function getNFTData(NFTID id) external view returns (ISCNFT memory);
 
     // Get information about an on-chain IRC27 NFT
+    // Note: the metadata.uri field is encoded as a data URL with:
+    // base64(jsonEncode({
+    //   "name": NFT.name,
+    //   "description": NFT.description,
+    //   "image": NFT.URI
+    // }))
     function getIRC27NFTData(NFTID id) external view returns (IRC27NFT memory);
 
     // Get the address of an ERC20NativeTokens contract for the given foundry serial number

packages/vm/core/evm/iscmagic/ISCTypes.sol

@@ -58,6 +58,12 @@ struct IRC27NFTMetadata {
     string standard;
     string version;
     string mimeType;
+    // Note: uri field is encoded as a data URL with:
+    // base64(jsonEncode({
+    //   "name": NFT.name,
+    //   "description": NFT.description,
+    //   "image": NFT.URI
+    // }))
     string uri;
     string name;
 }

packages/vm/core/evm/nfthack.go

@@ -0,0 +1,48 @@
+package evm
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/samber/lo"
+
+	"github.com/iotaledger/wasp/packages/isc"
+)
+
+// This hack is so that the ERC721 tokenURI view function returns the NFT name and description
+// for explorers
+type PackedNFTURI struct {
+	Name        string `json:"name"`
+	Description string `json:"description,omitempty"`
+	Image       string `json:"image"`
+}
+
+const dataURLPrefix = "data:application/json;base64"
+
+func EncodePackedNFTURI(metadata *isc.IRC27NFTMetadata) string {
+	return dataURLPrefix + "," + base64.StdEncoding.EncodeToString(lo.Must(json.Marshal(PackedNFTURI{
+		Name:        metadata.Name,
+		Description: metadata.Description,
+		Image:       metadata.URI,
+	})))
+}
+
+func DecodePackedNFTURI(uri string) (*PackedNFTURI, error) {
+	parts := strings.Split(uri, ",")
+	if len(parts) != 2 {
+		return nil, errors.New("cannot decode packed NFT URI: expected valid data URL")
+	}
+	if parts[0] != dataURLPrefix {
+		return nil, errors.New("cannot decode packed NFT URI: expected valid data URL")
+	}
+	b, err := base64.StdEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, fmt.Errorf("cannot decode packed NFT URI: %w", err)
+	}
+	var p *PackedNFTURI
+	err = json.Unmarshal(b, &p)
+	return p, err
+}