block-notifier's Introduction

block-notifier

Overview

Provide a standalone service, that can notify blockchain events via many channels

(listener) <-webhook- (notifier) <-filtered events- (watcher) <-crawled data- (blockchain network)

Packages:

block-notifier
base-watcher
eth-watcher
btc-watcher

Usage

Examples

const BlockNotifier = require('block-notifier');
const notifier = BlockNotifier.create({
  outputs: [
    {
      type: BlockNotifier.OUTPUT_TYPE.WEBHOOK,
      url: 'http://example.com'
    },
    {
      type: BlockNotifier.OUTPUT_TYPE.REDIS_PUBSUB,
      host: '127.0.0.1',
      ...
    }
  ]
});

const getWatchingAddresses = function(){...} // Method to get watching addresses with current logic.
const isWatchingTransaction = function(tx){...} // Method to filter out watching transaction
const EthWatcher = require('eth-watcher');
const events = [
  {
    type: EthWatcher.EVENT.TRANSFER,
    filter: EthWatcher.createFilter({toAddress: '0x140427a7D27144A4cDa83bD6b9052a63b0c5B589'})
  },
  {
    type: EthWatcher.EVENT.ERC20_TRANSFER,
    filter: EthWatcher.createFilter({
      tokenAddress: '0xd26114cd6EE289AccF82350c8d8487fedB8A0C07', // OmiseGO
      toAddress: getWatchingAddresses
    })
  },
  {
    type: EthWatcher.EVENT.TRANSFER,
    filter: EthWatcher.createFilter({txFilter: isWatchingTransaction})
  },
];
const watcher = EthWatcher.create({
  notifier,
  events,
});
watcher.start();

Classes

BaseWatcher

Can be extended to ETHWatcher, BTCWatcher, etc...
start() (void): ignite the engine
$create(WatcherConfig) (BaseWatcher): create watcher instance
$createFilter(FilterConfig) (BaseFilter): create events filter for watcher instance