CastVote.hs

    preconsuming choice CastVote: ContractId Doodle
      with
        voter: Party        
        option: Text
        inviteId: ContractId DoodleInvite
      controller voter
        do
          invite <- fetch inviteId
          assertMsg "this invite was issued for a different doodle" (invite.doodleName == name)
          assertMsg "the voter casting the vote does not match the voter who received the invite" (invite.voter == voter)
          assertMsg "the organizer who issued the invite is not the one who created this doodle" (invite.organizer == organizer)
          assertMsg "this doodle not is open" open
          assertMsg "voters is not one of the invited voters" (elem voter voters)
          assertMsg "this is not a valid option " (elem option options)
          let
            crtVotes = fromOptional (VotingSlot with count = 0, voted = []) (DA.TextMap.lookup option this.votes) 
            updatedVotes = DA.TextMap.insert option (VotingSlot with count = crtVotes.count + 1, voted = voter :: crtVotes.voted) this.votes
          assertMsg "each voter is only allowed to cast one vote per option" (notElem voter crtVotes.voted)
          create this with votes = updatedVotes