自己用的EventBus方法，采用单例模式来实现

上班期间因为业务需要写了一个简单的eventBus方法供自己使用，采用单例模式来实现相关的功能。

class EventBus {
  constructor() {
    this.events = {};
  }

  static get instance() {
    if (!this._instance) {
      this._instance = new EventBus();
    }
    return this._instance;
  }

  emit(type, params) {
    if (!this.events[type]) {
      return;
    }
    this.events[type].forEach((item) => {
      item.fun.call(this, params);
      if (item.isOnce) {
        this.removeEventListener(type, item.fun);
      }
    });
  }

  addEventListener(type, fun, isOnce = false) {
    if (!this.events[type]) {
      this.events[type] = [];
    }
    this.events[type].push({ fun, isOnce });
  }

  removeEventListener(type, fun) {
    if (!this.events[type]) {
      return;
    }
    const index = this.events[type].findIndex((item) => item.fun === fun);
    this.events[type].splice(index, 1);
  }

  once(type, fun) {
    this.addEventListener(type, fun, true);
  }
}

export default EventBus;

使用方法：

import EventBus from "@/utils/eventBus";
const eventBus = EventBus.instance;