observablestates-tradereporting

observable states cordapp

This CorDapp shows how Corda's observable states feature works. Observable states is the ability for nodes who are not participants in a transaction to still store them if the transactions are sent to them.

Concepts

In this CorDapp, we assume that when a seller creates some kind of HighlyRegulatedState, they must notify the state and national regulators. There are two ways to use observable states:

• By piggy-backing on FinalityFlow
• By distributing the transaction manually

The two approaches are functionally identical.

In this CorDapp, the seller runs the TradeAndReport flow to create a new HighlyRegulatedState. Then we can see that the seller will:

• Distribute the state to the buyer and the state regulator using FinalityFlow
• Distribute the state to the national regulator manually using the ReportManually flow

Usage

Pre-requisites:

See https://docs.corda.net/getting-set-up.html.

Running the CorDapp

Open a terminal and go to the project root directory and type: (to deploy the nodes using bootstrapper)

./gradlew clean deployNodes

Then type: (to run the nodes)

./build/nodes/runnodes

Interacting with the nodes:

Go to the CRaSH shell of Seller, and create a new HighlyRegulatedState

start TradeAndReport buyer: Buyer, stateRegulator: StateRegulator, nationalRegulator: NationalRegulator

The state will be automatically reported to StateRegulator and NationalRegulator, even though they are not participants. Check this by going to the shell of either node and running:

run vaultQuery contractStateType: com.observable.states.HighlyRegulatedState

You will see the new HighlyRegulatedState in the vault of both nodes.