paleite / chromia-workshop

Chromia Workshop

Prerequisites

1. Git
2. Node & NPM
3. Install JDK 17
4. Install Docker
5. Install Chromia CLI
6. Install Rell VS Code Plugin

Auction House

In this workshop we will build a basic auction house.

Run a local node

After having a local Postgres started you can run a local node by executing the command below.

chr node start

For convenience I've packaged defined a postgres in docker-compose.yml and provided a script to easily start it.

Seeding data

We are going to test out the updated typescript postchain-client and I've tested a test script for this under client/ah.ts.

You can execute it by running:

npm run auctions

Query your local node

Next lets try to query the node to list all the auctions.

chr query auction_house.list_all

Generating a keypair

In order to send transactions we will need a keypair.

chr keygen

Create a .secret file in the project and store your credentials, i.e.

privkey=...
pubkey=...
mnemonic=...

Sending transactions to your local node

The contract of the dapp specifies that we need to register a user, so let's do that first.

chr tx --secret .secret --await auction_house.register_user <pubkey> <name>

Try if you can place a bid of 10 on any of the auctions.

Updating the code of a local node

Modify the code so that auctions includes a default buyout price 15 and if a bid matches or is above that, then the auction is instantly settled and a balance of 15 is transferred.

After that, update the code that runs on the node.

chr node update