Category pages and product detail pages display a “breadcrumb” trail that reflects the navigational path to the page. For example, in the following illustration, the breadcrumb trail that leads to the current page is Home > Home Accents > Lamps and Lighting > Desk Lamps:

Each entry in the trail is a link to the corresponding category page. So, in the trail shown above, if the customer clicks Home Accents, the Home Accents category page is displayed.

If a customer accesses a product without proceeding through the navigational hierarchy, the breadcrumb trail reflects the default path to the product. There are several ways to make a navigational jump like this, such as clicking the link for a featured product or selecting a product returned by a search.

Navigation is tracked using the standard ATG Commerce historical navigation mechanism described in the ATG Commerce Guide to Setting Up a Store. The links to products displayed on various pages (e.g., category pages) pass parameters to the /atg/commerce/catalog/CatalogNavHistoryCollector servlet bean that specify modifications to the navigational history. The history is stored as a List of locations in the navHistory property of the /atg/commerce/catalog/CatalogNavHistory component. The breadcrumb trail is rendered by the store.war/navigation/gadgets/breadcrumbs.jsp gadget, which iterates over the navHistory property to display the locations it holds.