@truffle/events/EventManager.js

Event system for Truffle

const SubscriberAggregator = require("./SubscriberAggregator");
const Emittery = require("emittery");
const defaultSubscribers = require("./defaultSubscribers");

class EventManager {
  constructor(config) {
    this.emitter = new Emittery();
    this.subscriberAggregators = [];

    this.initializationOptions = {
      config,
      emitter: this.emitter
    };
    this.initializeDefaultSubscribers(this.initializationOptions);
  }

  emit(event, data) {
    return this.emitter.emit(event, data);
  }

  initializeDefaultSubscribers(initializationOptions) {
    const aggregatorOptions = {
      ...initializationOptions,
      subscribers: defaultSubscribers
    };
    this.subscriberAggregators.push(
      new SubscriberAggregator(aggregatorOptions)
    );
  }

  initializeUserSubscribers(initializationOptions) {
    const { subscribers } = initializationOptions;
    if (subscribers && Object.keys(subscribers).length > 0) {
      const aggregatorOptions = Object.assign({}, initializationOptions, {
        emitter: this.emitter
      });
      this.subscriberAggregators.push(
        new SubscriberAggregator(aggregatorOptions)
      );
    }
  }

  updateSubscriberOptions(newOptions) {
    this.subscriberAggregators.forEach(aggregator => {
      aggregator.updateSubscriberOptions(newOptions);
    });
  }
}

module.exports = EventManager;