How do I create a gRPC Value object for Tuple ContractKey when using the Ledger API?

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Hi all,

I’m building a java backend using the reactive bindings. I have a template with contract key as below:

key (networkOwner, client, productId): (Party, Party, Text)
maintainer key._1

In my java I’m trying to send an ExerciseByKeyCommand through the Ledger API to exercise a choice in this template, but it is unclear how to correctly create the Value object to represent the contract key. Any advice would be greatly appreciated!

Thanks in advance!

2

Tuples are not builtin types in Daml-LF. They are just regular records named TupleN in DA.Types. This is documented in How Daml types are translated to Daml-LF — Daml SDK 1.16.0 documentation.

The package id is stable and is 40f452260bef3f29dede136108fc08a88d5a5250310281067087da6f0baddff7 if you really want to hardcode it but I recommend using the Java codegen instead to get it.

1 Like
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Thanks for the reply, I did catch this, yes.

Doing that would give me a da.types.Tuple3 object but the ExerciseByKeyCommand object requires a Value as the key. I couldn’t see a way to clearly add an object to the Value builder, in place of things like setText/setParty/setDate, what’s the best way to create a Value from the da.types.Tuple3?

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You should be able to call toValue to get a DamlRecord which is a subclass of Value.