@shopgate/pwa-tracking/streams/cart.js

Tracking library for the Shopgate Connect PWA.

import 'rxjs/add/operator/switchMap';
import 'rxjs/add/observable/of';
import 'rxjs/add/observable/defer';
import { Observable } from 'rxjs/Observable';
import { productsAdded$ as originalProductsAdded$ } from '@shopgate/engage/cart/streams';
import { getProductById, fetchProductsById } from '@shopgate/engage/product';

/**
 * Emits when a product was added to the cart and product data is available
 */
export const productsAdded$ = originalProductsAdded$.switchMap(input => {
  const {
    getState,
    action,
    dispatch
  } = input;
  const {
    products = []
  } = action;

  // Collect product ids from the add-to-cart action
  const productIds = products.map(({
    productId
  }) => productId).filter(Boolean);

  // Check if we have product data for all productIds
  const productDataAvailable = productIds.every(productId => getProductById(getState(), {
    productId
  }));
  if (productDataAvailable) {
    // All product data for the tracking event is available - handover action data to subscribers
    return Observable.of(input);
  }

  /**
   * Incomplete product data can be caused by an add-to-cart push message. In that case the
   * product was never fetched before due to visiting PDP. So we need to fetch missing product
   * data first.
   * Subscribers will receive the original action when product data comes available.
   */
  return Observable.defer(async () => {
    let result = {
      products: []
    };
    try {
      result = await dispatch(fetchProductsById(productIds));
    } catch (e) {
      // nothing to do here - default result will be returned
    }
    return result;
  }).first()
  // do not proceed when request didn't return any products (no suitable tracking data)
  .filter(data => Array.isArray(data.products) && data.products.length > 0)
  // handover original action to subscribers
  .switchMap(() => Observable.of(input));
});