Daml Connect 1.10.0 has been released on Wednesday February 17th. You can install it using:
daml install 1.10.0
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DA.Map and DA.Set libraries are
Background
Daml Triggers are a framework to add automation to your Daml application with maximum code reuse from contracts and scripts. Triggers are written in Daml, and have similar capabilities to Daml Script/REPL, but are run in reaction to ledger events rather than as one-offs. They provide an easy way to maintain functional dependencies between contracts, or to add automation of the kind that lets users auto-accept all incoming asset transfers from another party.
Daml Triggers are operated via a hosting service that is designed to run as part of Daml Connect, next to the JSON API. It allows users to authorize automation to act on their behalf. So in the above example, the user doesn’t have to host the auto-accept automation themselves, but instead authorizes the host service to run it on their behalf.
To make that authorization work smoothly we had to solve a separate problem that developers previously had to solve themselves: Keeping a long-running service supplied with valid JWT tokens to use on the Ledger API. Our solution for this problem is now also available as a stand-alone component - the OAuth 2.0 Middleware - so that everyone can profit from this development. The middleware can be deployed to sit between an OAuth 2.0 identity provider and any long-running Ledger API client. It manages initial authorization and handles refresh tokens so that its clients can easily get fresh JWTs without implementing the OAuth protocol in full by themselves.
Furthermore, solving this problem via a middleware adds a layer of abstraction between Daml Connect components and IAM systems. The Daml Trigger Host, for example, could be deployed against a completely different IAM system by implementing an auth middleware that provides the same simple API towards the client application.
Specific Changes
--auth and --auth-callback command-line flags. Please refer to the Authorization chapter of the trigger service documentation for further instructions.
Impact and Migration
Users of Daml Triggers are advised to switch from using the daml trigger CLI command to using the Trigger service, either via daml trigger-service or the stand-alone JAR file as that’s the only supported way to run triggers in production. daml trigger is intended only as a development tool to spin up a single ephemeral trigger for testing.
Background
Daml-LF is Daml’s intermediary language, analogous to Java bytecode. With Daml Connect 1.10, Daml-LF 1.11 is now stable and frozen. Daml-LF 1.11 introduces two new language features: Choice Observers and Generic Maps. In addition, Daml Script, REPL and Triggers now properly convert from ContractId a value to Text using the show function.
Daml-LF 1.11 is not yet the default yet, but will be from the next Daml Connect release in March 2021. In the meantime, to use the new features, your project has to explicitly target Daml-LF 1.11. You can enable this in your daml.yaml file by adding stanza:
build-options:
- --target=1.11
Specific Changes
--target=1.11.observer to the choice … syntax. Parties designated choice observers using that keyword are guaranteed to see the exercise of the choice. This can be useful for defining custom events, for example:
nonconsuming choice MyEvent : ()
with
message: Text
sender: Party
receivers: [Party]
observer receivers
controller sender
do
return ()
Here the parties in receivers will all see an exercise node of type MyEvent with a payload containing message.
GenMap and standard library modules DA.Map and DA.Set allowing maps and sets with arbitrary serializable types as keys/members. This supersedes the TextMap type and standard library modules DA.Next.Map and DA.Next.Set, which required conversion functions between the key type and Text. The DA.Next.* libraries are deprecated for use with Daml-LF >= 1.11.TextMap itself continues to be supported as there are use-cases where it provides a nicer representation on the API than GenMap. Generic maps are represented as lists of tuples on the APIs. In contrast, TextMap is represented as a JSON object on the JSON API.Show now return the actual contract id in Daml Script, REPL, and Triggers, rather than the opaque ”<contract-id>” that’s returned in Daml contracts.
Impact and Migration
Users of DA.Next.* are advised to switch to TextMap or DA.Map/DA.Set with the upgrade to Daml-LF 1.11. However, DA.Next.* will continue to be maintained for full backwards compatibility in the 1.X release line.
daml codegen have had their dependencies updated
If this causes problems with dependency resolution in consuming projects, we recommend updating dependencies there, too, in order to apply the latest security patches.
daml damlc that were never meant to be public are now hidden from the output of various daml xxx --help commands. The options still have the same effect when present. The options did not work universally as they were primarily intended for internal use. If you do use them please let us know about your use-case so we can consider supporting it properly. The affected flags are:
--with-dlint--without-dlint--allow-overrides
Background
See Daml-LF 1.11 above for background to Daml-LF. Daml-LF 1.12 is now included as an early access feature. Its main improvements are on performance, reducing transaction size through type erasure. It can be used in your project by adding the following stanzas to your daml.yaml file:
build-options:
- --target=1.12
sandbox-options:
- --early-access-unsafe
Note that projects using early access Daml-LF versions can not be deployed to production ledgers.
CommandDeduplicationIT now sets the deduplication timeout on commands using the parameter passed to --timeout-scale-factor, allowing it to run on ledger configurations that require more than 3 seconds to commit a submission.--client-auth for kvutils config--tracker-retention-period parameter to the kvutils CLI to be able customization of how long the command service will keep an active command tracker for a given party.