Multiple party agreement

Questions
1

I’ve been following the documentation on how to setup a Multiple Party Agreement. (Great improvement to the documentation by the way. This was much needed)

My issue is that in the documentation example the observers are a party in the final contract to be created. However, in the multiple party agreement that I am creating, the observers are in a different contract called Guild.

So I included guild as

guild: Guild in my pending contract so that I could use the members party as observers. However, in setting this up, I am getting an error which I think is because I have included this incorrectly(?)

Could someone please give me some guidance?

Also, in the documentation example, the code used for sorting a list is just sort but I actually had to use DA.List.Sort ? Is that because of some change to the SDK?

Here is the error message

/Users/khurammalik/DevTree/Qirad Agent Network/app/daml/Qirad.daml:126:19: error:
    • No instance for (DA.Internal.Record.HasField
                         "member" Guild [Party])
        arising from a use of ‘DA.Internal.Record.getField’
    • In the first argument of ‘DA.List.sort’, namely
        ‘(DA.Internal.Record.getField @"member" guild)’
      In the second argument of ‘(==)’, namely
        ‘DA.List.sort (DA.Internal.Record.getField @"member" guild)’
      In the first argument of ‘assert’, namely
        ‘(DA.List.sort approvingmember
            == DA.List.sort (DA.Internal.Record.getField @"member" guild))’

Here is my Guild , proposal and `ProposalGuildApproval’ code for reference.

template Guild with
    guildName: Text
    creator: Party
    members: [Party]
  where
    signatory creator, members
    ensure length members >= 4 && DA.List.unique members

template Proposal with
    issuer: Party
    investor: Party
    guild: Guild
    projectdescription: Text
    unitsrequired: Int
    marketingcost: Int
    distributioncost: Int
    additionalcost: Int
    proposalId: Text -- Key
    item: Item

  where
    signatory issuer, guild.members
    observer investor

template ProposalGuildApproval with
    signedproposal: Proposal
    guild: Guild
    approvingmember: [Party]

  where
     signatory approvingmember
     observer guild.members

     ensure 
      DA.List.unique approvingmember
-- The parties who need to approve is the guild.members with approvingmember filtered out     
     let toApprove = filter (`notElem` approvingmember) guild.members

     preconsuming choice Approve : ContractId ProposalGuildApproval with
        approver : Party
      controller approver
        do
          -- Check the approver is in the toApprove list, and if they are, approve the ProposalGuildApproval contract
          assert (approver `elem` toApprove)
          create this with approvingmember = approver :: approvingmember

     preconsuming choice FinaliseApproval : ContractId Proposal with
        approver : Party
      controller approver
        do
          -- Check that all the required signatories have signed Pending
          assert (DA.List.sort approvingmember == DA.List.sort guild.member)
          create signedproposal
1 Like
2

The error is in this line

          assert (DA.List.sort approvingmember == DA.List.sort guild.member)

There is a typo in the field name: member instead of members. So try

          assert (DA.List.sort approvingmember == DA.List.sort guild.members)
1 Like
3

Gah! Thank you – so sorry for wasting your time!

4

Nothing to be sorry for, we’ve all been in the situation where we’ve stared at our code very confused until someone else pointed out the typo :slight_smile:

2 Likes
5

Thanks again :slight_smile:

1 Like