Encode payload data for CreateMetadataAccountV3 (with Collections Details)

[mihneacalugaru]

I am aware that there has not yet been released a version which takes into account certified collections. Anyway, I do plan to make the necessary adjustments to the existing code so as to allow creating a collection.

From my understanding, for creating a certified collection, the following are needed:

• Changing MetadataProgram.CreateMetadataAccount function so as to also encode the collectionDetails. However, I tried to change it according to the order, offsets and sizes of arguments listed here https://docs.metaplex.com/programs/token-metadata/instructions#create-a-metadata-account and I don't seem to manage to get it working. My modified version of MetadataProgram.CreateMetadataAccount is:

  private static byte[] EncodeCreateMetadataAccountData(MetadataParameters parameters, int? collectionDetailsSize = null, bool isMutable = true)
      {
          byte[] bytes = Encoding.UTF8.GetBytes(parameters.name);
          byte[] bytes2 = Encoding.UTF8.GetBytes(parameters.symbol);
          byte[] bytes3 = Encoding.UTF8.GetBytes(parameters.uri);
          MemoryStream memoryStream = new MemoryStream();
          BinaryWriter binaryWriter = new BinaryWriter(memoryStream);
          binaryWriter.Write((byte)0);
          binaryWriter.Write(bytes.Length);
          binaryWriter.Write(bytes);
          binaryWriter.Write(bytes2.Length);
          binaryWriter.Write(bytes2);
          binaryWriter.Write(bytes3.Length);
          binaryWriter.Write(bytes3);
          binaryWriter.Write((ushort)parameters.sellerFeeBasisPoints);
          int num;
          if (parameters.creators != null)
          {
              List<Creator> creators = parameters.creators;
              num = ((creators != null && creators.Count < 1) ? 1 : 0);
          }
          else
          {
              num = 1;
          }
  
          if (num != 0)
          {
              binaryWriter.Write((byte)0);
          }
          else
          {
              binaryWriter.Write((byte)1);
              binaryWriter.Write(parameters.creators.Count);
              foreach (Creator creator in parameters.creators)
              {
                  byte[] buffer = creator.Encode();
                  binaryWriter.Write(buffer);
              }
          }
  
          // collection - ADDED BY ME
          binaryWriter.Write((byte)0);
  
          // uses  - ADDED BY ME
          binaryWriter.Write((byte)0);
  
          binaryWriter.Write(isMutable);
  
          // - whole below if-else block ADDED BY ME
          if (collectionDetailsSize != null)
          {
              binaryWriter.Write((byte)1);
  
              byte[] collectionDetailsByteArray = new byte[8];
              var collectionDetailsSizeBytes = BitConverter.GetBytes(collectionDetailsSize.Value);
  
              collectionDetailsSizeBytes.CopyTo(collectionDetailsByteArray, 0);
  
              binaryWriter.Write(collectionDetailsByteArray);
          }
          else
          {
              binaryWriter.Write((byte)0);
          }
  
          return memoryStream.ToArray();
      }

I always get a deserialization exception from the on-chain program. I am using testnet at the moment. Can you help me get the encoding of the collectionDetails right until the feature will be implemented in this repo? Also, as I am in the need of using this quite often, I will be delighted to also contribute to the project.

Thank you very much!

[BifrostTitan]

Ive implemented MetadataAccount V3 instructions.

This is what you were looking for. It took me several hours to figure this out.

        if(collectionDetails == 0)
        {
            writer.Write((byte)0);  // 0 = null | No collection details
        }
        else
        {
            writer.Write((byte)1);
            writer.Write((byte)0); // collection detail size sits in an array - this byte defines its position | should always be 0
            writer.Write((ulong)collectionDetails); //collection details size of V1 defined as a ulong

        }