The Vue Storefront Essentials Course is now available! Learn More
Facet normalizer

Facet normalizer

Concept of facets exists in both Unified Data Layer world and SAP. The normalizeFacet function maps SAP Facet into Unified SfFacet.


NameTypeDefault valueDescription
facetFacetSAP Facet
ctxNormalizeFacetContextContext which contains currentQuery for searchProducts


The SfFacet is returned from SearchProducts Method. If the SfFacet structure doesn't contain the information you need for your Storefront, you can extend its logic using the defineNormalizers function. The following example demonstrates how to extend SfFacet with a multiSelect field.

import { normalizers as normalizersSAP, defineNormalizers } from "@vsf-enterprise/unified-api-sapcc";

const normalizers = defineNormalizers<typeof normalizersSAP>()({
  normalizeFacet: (facet) => ({
    multiSelect: facet.multiSelect,


In the Unified Data Layer, the SfFacet array is expected to return all of the available facets, including the current selected facets. In SAP the selected facets are present in the currentQuery object returned from the searchProducts API Client method. So to retrieve them, we have to extract them from the query value. An explanation of the expected behaviour can be found in the facet.feature file which contains test scenarios.

import { SfFacetTypes, type SfFacet, type SfFacetType } from "@vue-storefront/unified-data-model";
import type { Facet, FacetValue } from "@vsf-enterprise/sapcc-types";
import type { NormalizerContext } from "@/normalizers/types";
import { maybe } from "@shared/utils";

export function normalizeFacet(facet: Facet, ctx: NormalizerContext): SfFacet | null {
  const { name: label, values } = facet;
  const name = normalizeFacetName(facet);
  const selectedValues = getSelectedValues(ctx.currentQuery?.query?.value ?? "", name);

  const sfFacetItems =
    values?.map((term) => ({
      label: as string,
      value: normalizeFacetItemValue(term, selectedValues),
      productCount: maybe(term.count),
    })) || [];

  if (sfFacetItems.length === 0) {
    return null;
  const { getFacetType = defaultGetFacetType } = ctx;

  return {
    label: label as string,
    name: normalizeFacetName(facet),
    values: sfFacetItems,
    type: getFacetType(facet),

function normalizeFacetName(facet: Facet): string {
  let name = as string;
  const nonSelectedValue = facet.values?.find((value) => !value?.selected);
  const exampleQueryUrl = nonSelectedValue?.query?.query?.value;

  if (exampleQueryUrl) {
    name = exampleQueryUrl.split(":").at(-2) ?? name;

  return name;

function normalizeFacetItemValue(facetValue: FacetValue, selectedValues: string[]): string {
  let value = as string;
  const queryUrl = facetValue?.query?.query?.value;

  if (facetValue.selected) {
    value = guessSelectedFacetItemValue(value, selectedValues);
  } else if (queryUrl) {
    value = queryUrl.split(":").at(-1) ?? value;

  return value;

function getSelectedValues(queryValue: string, facetName: string): string[] {
  const regex = new RegExp(`:${facetName}:([^:]+)`, "g");
  const matches = queryValue.match(regex);
  if (matches) {
    return => match.split(":")?.[2]).filter(Boolean);
  return [];

function guessSelectedFacetItemValue(facetItemName: string, selectedValues: string[]): string {
  const facetNameAsUri = encodeURIComponent(facetItemName as string).replace(/%20/g, "+");
  return (
    selectedValues.find((value) => value.toLowerCase() === facetNameAsUri.toLowerCase()) ??

function defaultGetFacetType(facet: Facet): SfFacetType {
  return facet.multiSelect === false ? SfFacetTypes.SINGLE_SELECT : SfFacetTypes.MULTI_SELECT;