indexer.js

/*
* Creates a new websocket client that connects to the Loom Instance
*/
const client = new Client(
  'default',
  'ws://127.0.0.1:46658/websocket',
  'ws://127.0.0.1:46658/queryws',
)
/*
* Creates our Elasticsearch client
*/
const esclient = new elasticsearch.Client({
  host: 'localhost:9200',
  log: 'trace'
});

/*
* Creates web3 provider that allows us to call Solidity functions via javascript
*/
const web3 = new Web3(new LoomProvider(client, indexerPrivateKey))
const ABI = HackerNoon.abi;
const indexerClientInstance = new web3.eth.Contract(
  ABI, 
  HackerNoon.networks.default.address,
  { 
    from: indexerUserAddress 
  }
);

/*
* Sends a new Document to the Elasticsearch index every time a StoryPublished is emitted
* The document contains title, text and the author address
*/
indexerClientInstance.events.StoryPublished((err, event) => {
  if (err) console.error('Error on event', err);
  const {storyId, owner, title, text} = event.returnValues;
  esclient.create({
    index: 'stories',
    type: '_doc',
    id: storyId.toString(),
    body: {
      title: title,
      text: text,
      writer: owner,
    }
  });
});