@drizzle-utils/new-block-stream

A tool for creating a stream of new block data.

Usage

Getting started

Install via npm:

npm install @drizzle-utils/new-block-stream

Usage example (taken from @drizzle-utils/new-block-stream/example.js)

const Web3 = require("web3");
const createNewBlock$ = require("@drizzle-utils/new-block-stream");

const web3 = new Web3("ws://127.0.0.1:9545");

const { observable, cleanup } = createNewBlock$({
  web3,
  pollingInterval: 200, // only used if non-WebsocketProvider
});

// log out new blocks
observable.subscribe(block => console.log(block));

// stop listening to new blocks and end the stream
cleanup();

Note that listening to new blocks might skip blocks if polling is being used and the pollingInterval is longer than the rate in which new blocks are being produced.

API

createNewBlock$

Creates an RxJS observable that will monitor the blockchain for new blocks. Supports both Web3 subscriptions and polling.

Parameters

options - Object

• web3 - Object: A Web3 instance
• pollingInterval (only used for non-WebsocketProvider) - Number: The rate in milliseconds at which the stream should poll for new blocks.

Returns

Object

• observable: An RxJS observable.
• cleanup: A function for cleaning up listeners and completing/ending the streams created.
• subscription: This is only returned if the provider passed-in is a WebsocketProvider. This is a reference to the underlying Web3 subscription object.