Error: Attempt to fetch or exercise a contract not visible to the committer

Questions
1

Mod note: As of SDK 1.5.0 Scenarios have been superseded by the more powerful Daml Script. We now recommend using that for all purposes. For more information, and to learn how to use Script please check out @Andreas’ post on our blog.

Here is my code

 template Attandance 
        with
            systemUser : Party
            associate : Optional Party
            punchInTime : Optional Time
            punchOutTime :Optional Time
        where 
            signatory systemUser
            nonconsuming choice PunchIn 
                : ContractId Attandance
                with
                    currentTime : Time
                controller associate 
                   do 
                    create this with punchInTime = Some currentTime 
            nonconsuming choice PunchOut 
                : ContractId Attandance
                with
                    currentTime : Time
                controller associate 
                   do 
                    create this with punchOutTime = Some currentTime

Here is my scenario of update punchIn

setup = do 
   systemUser <- getParty "Alice"
   associate  <- getParty "Bob"

atid <- submit systemUser do
        create Attandance
            with
                systemUser
                associate  = None   
                punchInTime = None
                punchOutTime = None   
 submit associate do
        exercise asid PunchIn with
            currentTime <- getTime
    return()

Attempt to fetch or exercise a contract not visible to the committer.
** Contract: #2:0 (Attendence:Attandance)**
** Committer: 'Bob**
** Disclosed to: 'Alice**
I know why this error occur because systemUser create Attendance and associate exercise the choice but systemUser has to create attendance and associate PunchIn or PunchOut, I make “associate” observer, but it not solved.

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2

Looks like you need to take care of two things.

Firstly, you need to actually pass the associate to the Attendance contact, by setting associate = Some associate.

Secondly, you need to declare the associate as an observer of a contract, by stating observer associate underneath the signatory line of the contract.

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3

associate entity enters only in Attendance when he PunchIn,

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4

And I create associate as observer but it dont work.

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5

I’m afraid you’re going to have to somehow pass in your associate, or the contract will not be visible to them.

DAML contracts are private; you have to explicitly declare the parties that can see them. If a party needs to be able to exercise a choice on a contract, the signatory first needs to make them an observer.

In this case, you need to pass in your associate before punching in or out. If the associate is unknown when the contract is created, you’ll need a kind of two-phase flow, in which the signatory can exercise a choice to add an associate to the contract.

1 Like
6

@Muhammad_Moiz

Could you post an example, in particular how you create the Attendance instance and specify the associate. If it is the same as what you originally posted, then

associate  = None

does not specify a party as the associate` on that contract.

1 Like