完整地替代命名空间和事件代理，链接到 https://github.com/oneuijs/oui-dom-events

• 5.0 Document ready by DOMContentLoaded

  // jQuery
  $(document).ready(eventHandler);
  // Native
  // 检测 DOMContentLoaded 是否已完成
  if (document.readyState === 'complete' || document.readyState !== 'loading') {
    eventHandler();
  } else {
    document.addEventListener('DOMContentLoaded', eventHandler);
  }

• 5.1 使用 on 绑定事件

  // jQuery
  $el.on(eventName, eventHandler);
  // Native
  el.addEventListener(eventName, eventHandler);

• 5.2 使用 off 解绑事件

  // jQuery
  $el.off(eventName, eventHandler);
  // Native
  el.removeEventListener(eventName, eventHandler);

• 5.3 Trigger

  // jQuery
  $(el).trigger('custom-event', {key1: 'data'});
  // Native
  if (window.CustomEvent) {
    const event = new CustomEvent('custom-event', {detail: {key1: 'data'}});
  } else {
    const event = document.createEvent('CustomEvent');
    event.initCustomEvent('custom-event', true, true, {key1: 'data'});
  }
  el.dispatchEvent(event);