daml | The Daml smart contract language | Blockchain library

Yes! This is explained in the documentation for Daml Script, specifically:

You can use Daml script to initialize a ledger on startup. To do so, specify an init-script: ScriptExample:initializeFixed field in your daml.yaml. This will automatically be picked up by daml start and used to initialize sandbox.

In your case, that would be:

This means that Alice saw the creation of the new contract (#8:2) because she was a party to the old contract (#6:2) at the time it was consumed by Bob exercising AcceptAssetTransfer on HolderRole. The implications are that Alice could see that Bob became the new owner of Asset but will not see any future events that involve Asset such as it being archived as a result of sending the asset to another Party.

Additionally even though Alice saw/witnessed the creation of the new contract she cannot query for it after the one time event where she witnessed it.

Sometimes the docs are a bit hard to search so here's some relevant links:

• A simple overview of the meaning of S, O, W, and D in the Script output
• The ledger privacy model
• A more detailed explanation on witnessing and divulgence
• An explanation of contract consumption in general

As this question was also asked simultaneously on our forum further discussion may be located here.

The $ operator is a substitute for parenthesis. The example

The signatories of a contract need to be computable from the contract arguments. You can't reference another contract by ContractId and get them from there. The reason is that that other contract might be archived, in which case you suddenly have a contract for which the signatories can't be read.

So your Proposal must contain the agent that is making the proposal:

daml test opens a separate gRPC server and connects to that. Based on the error, it looks like this connection isn’t working properly. Do you have some kind of firewall enabled that could block this?

Do you encounter the same issue in daml studio?

I tried reproducing this in SDK 1.6.0 but was unable to do so. It would be great if you could provide the SDK version and the operating system you are running this on.

gRPC will use the http_proxy and https_proxy environment variables. Try setting no_proxy=127.0.0.1 to disable it for the requests to localhost.

DAML-on-Sawtooth is a specific DAML ledger implementation integrated using a full Sawtooth network deployment. leveraging Sawtooth's validation features for persistence.

The rest-api you see in that repository is actually the Sawtooth REST api used for communicating to the Sawtooth network, and that validator an implementation of Sawtooth validation as part of the commit protocol, and the transaction processor to handle DAML transactions on the Sawtooth network.

The sawtooth-daml-rpc is what implements the DAML Ledger API gRPC services, and this exposes the Ledger API that the application code interacts with. Postgres is used as an underlying index db service supporting the Ledger API.

In the https://docs.daml.com/getting-started/app-architecture.html you can conceptually swap the "Sandbox" box with "Sawtooth Network", as in the DAML-on-Sawtooth case it is the full Sawtooth network which is able to consume and return DAML that is the ledger implementation.

As with all DAML ledgers, the DAR files are uploaded through the package upload gRPC APIs and are persisted on the ledger (in this case the Sawtooth network), as are parties and transactions through the party allocation and transaction submission APIs, respectively.

Parties don't have a cryptographic identity in DAML Ledgers, only nodes do. As part of the shared ledger state, every DAML-enabled infrastructure maintains a mapping from Party to Node. This relationship is usually described as a Node "hosting" a Party. The Node hosting a Party is able to submit transactions using that Party's authority and is guaranteed to receive any transactions visible to that Party.

In the tutorial you are referring to, all parties are allocated on a single Node, which then hosts them. This does indeed not make that much sense in practice. It would be more sensible to set up a network with three orgs and allocate the three parties on the peer nodes in the three orgs, respectively. Given the way the example is set up, that should be straightforward.

This issue is not linked to the java code but to the OWLS-S file syntaxe. you can resolve this issue by replacing:

It would be easier to answer if you provided the erroneous code, but from what I can parse, it looks like you may be misunderstanding what Map.empty is. Map.empty is not a function, it is a value; specifically, it is a Map that has no content.

Maps are sets of key/value pairs. One way to construct the Map that you want is to start with an empty Map and then add each of the elements that you want, one by one. Here is an example: