eventTracking.ts

import eventTracking from './events';
import { createStore, combineReducers, applyMiddleware } from 'redux';

const trackEvent = (properties, state) => {
  ReactGA.event(properties); // Track event to google analytics
  
  // Here we can get extra data from our state to attach to the event.
  const bigQueryRecord = createRecord(buildRecordParam(properties, state));
  postBigQueryEvent(bigQueryRecord); // Track event to BigQuery
};

const trackingMiddleware = store => next => action => {
  if (action.type === '@@router/LOCATION_CHANGE') {
    const nextPage = `${action.payload.pathname}${action.payload.search}`;
    trackPage(nextPage, store.getState());
  }

  if (eventTracking[action.type]) {
    trackEvent(eventTracking[action.type], store.getState());
  }

  return next(action);
};

// Apply the middleware like this
let myApp = combineReducers(reducers)
let store = createStore(
  myApp,
  applyMiddleware(
    trackingMiddleware
  )
);