ext-chatwork-events/index.js

Chatwork DOM Events wrapper for Chrome extension

'use strict'

const EventEmitter = require('eventemitter2').EventEmitter2

const $ = (selector) => {
  if (selector[0] === '#') {
    return document.getElementById(selector.slice(1))
  } else {
    return document.querySelectorAll(selector)
  }
}

const observe = (el, opts, callback) => {
  let mutation = new MutationObserver((mutations) => mutations.forEach(callback))
  mutation.observe(el, opts)

  return mutation
}

const filter = (list, predicate) => {
  if (!Array.isArray(list)) {
    list = Array.from(list)
  }

  return list.filter(predicate)
}

const dig = (obj, attrName) =>
  attrName.split('.').reduce((memo, prop) =>
    memo && memo[prop] ? memo[prop] : null, obj
  )

const attrIs = (attrName, expected) => (obj) =>
  dig(obj, attrName) === expected

const hasClass = (className) => (el) =>
  el.classList.contains(className)

const eventOptions = {
  delimiter: ':',
}

const Events = new EventEmitter(eventOptions)

document.addEventListener('DOMContentLoaded', () => {
  const loadingObserver = observe($('#_loader'), {
    attributes: true,
    attributeFilter: ['style'],
  }, (mutation) => {
    if (mutation.target.style.display === 'none') {
      Events.emit('ready')
      loadingObserver.disconnect()
    }
  })

  observe($('#_timeLine'), {
    childList: true,
  }, (mutation) => {
    const added = filter(mutation.addedNodes, hasClass('_message'))
    added.forEach((node) => Events.emit('messages:add', node))

    const removed = filter(mutation.removedNodes, hasClass('_message'))
    removed.forEach((node) => Events.emit('messages:remove', node))
  })
}, false)

if (window) {
  window.ChatworkEvents = Events
} else {
  module.exports = Events
}