func()

in src/frontend/handlers.go [144:209]
56 lines of code
10 McCabe index (conditional complexity)

func (fe *frontendServer) productHandler(w http.ResponseWriter, r *http.Request) {
	log := r.Context().Value(ctxKeyLog{}).(logrus.FieldLogger)
	id := mux.Vars(r)["id"]
	if id == "" {
		renderHTTPError(log, r, w, errors.New("product id not specified"), http.StatusBadRequest)
		return
	}
	log.WithField("id", id).WithField("currency", currentCurrency(r)).
		Debug("serving product page")

	p, err := fe.getProduct(r.Context(), id)
	if err != nil {
		renderHTTPError(log, r, w, errors.Wrap(err, "could not retrieve product"), http.StatusInternalServerError)
		return
	}
	currencies, err := fe.getCurrencies(r.Context())
	if err != nil {
		renderHTTPError(log, r, w, errors.Wrap(err, "could not retrieve currencies"), http.StatusInternalServerError)
		return
	}

	cart, err := fe.getCart(r.Context(), sessionID(r))
	if err != nil {
		renderHTTPError(log, r, w, errors.Wrap(err, "could not retrieve cart"), http.StatusInternalServerError)
		return
	}

	price, err := fe.convertCurrency(r.Context(), p.GetPriceUsd(), currentCurrency(r))
	if err != nil {
		renderHTTPError(log, r, w, errors.Wrap(err, "failed to convert currency"), http.StatusInternalServerError)
		return
	}

	// ignores the error retrieving recommendations since it is not critical
	recommendations, err := fe.getRecommendations(r.Context(), sessionID(r), []string{id})
	if err != nil {
		log.WithField("error", err).Warn("failed to get product recommendations")
	}

	product := struct {
		Item  *pb.Product
		Price *pb.Money
	}{p, price}

	// Fetch packaging info (weight/dimensions) of the product
	// The packaging service is an optional microservice you can run as part of a Google Cloud demo.
	var packagingInfo *PackagingInfo = nil
	if isPackagingServiceConfigured() {
		packagingInfo, err = httpGetPackagingInfo(id)
		if err != nil {
			fmt.Println("Failed to obtain product's packaging info:", err)
		}
	}

	if err := templates.ExecuteTemplate(w, "product", injectCommonTemplateData(r, map[string]interface{}{
		"ad":              fe.chooseAd(r.Context(), p.Categories, log),
		"show_currency":   true,
		"currencies":      currencies,
		"product":         product,
		"recommendations": recommendations,
		"cart_size":       cartSize(cart),
		"packagingInfo":   packagingInfo,
	})); err != nil {
		log.Println(err)
	}
}