gab-social/app/javascript/gabsocial/middleware/loading_bar.js

import isObject from 'lodash.isobject'
import { showLoading, hideLoading } from 'react-redux-loading-bar'

const defaultTypeSuffixes = ['PENDING', 'FULFILLED', 'REJECTED']

export default function loadingBarMiddleware(config = {}) {
  const promiseTypeSuffixes = config.promiseTypeSuffixes || defaultTypeSuffixes

  return ({ dispatch }) => (next) => (action) => {
    if (isObject(action) && action.type && action.type.indexOf('TIMELINE') > -1) {
      const [PENDING, FULFILLED, REJECTED] = promiseTypeSuffixes

      const isPending = new RegExp(`${PENDING}$`, 'g')
      const isFulfilled = new RegExp(`${FULFILLED}$`, 'g')
      const isRejected = new RegExp(`${REJECTED}$`, 'g')

      if (action.type.match(isPending)) {
        dispatch(showLoading())
      } else if (action.type.match(isFulfilled) || action.type.match(isRejected)) {
        dispatch(hideLoading())
      }
    }

    return next(action)
  }
}