getChatMessages.js

export default async function getChatMessages(chatUrl) {
  // ...

  // Create RDFJS dataset
  const dataset = await new Promise((resolve, reject) => {
    const dataset = Dataset();

    const parserN3 = new ParserN3({ baseIRI: dataUrl })
    const input = new Readable({
      read: () => {
        input.push(chatTtl)
        input.push(null)
      }
    })
    const output = parserN3.import(input)
    output.on('data', quad => {
      dataset.add(quad)
    })
    output.on('prefix', (prefix, ns) => {
      // console.log(`prefix: ${prefix} ${ns.value}`)
    })
    output.on('end', () => {
      resolve(dataset)
    })
  })

  // Use clownface to extract desired data
  const FLOW_MESSAGE = namedNode("http://www.w3.org/2005/01/wf/flow#message");
  const CONTENT = namedNode("http://rdfs.org/sioc/ns#content");
  const MAKER = namedNode("http://xmlns.com/foaf/0.1/maker");
  const chatNode = cf({ dataset }).namedNode(nodeUrl);
  const messages = chatNode.out(FLOW_MESSAGE).map((messageNode) => {
    return {
      nodeName: messageNode.value,
      author: messageNode.out(MAKER).value,
      content: messageNode.out(CONTENT).value
    }
  })
  return messages
}