ATG Commerce Search Guide

A facet trail is similar to a navigational breadcrumb trail, where each entry consists of a facet and a selection value or range for that facet. For example, a facet trail might appear on the page like this:

The CommerceFacetTrailDroplet takes as input a String representation of the current facet trail plus instructions for modifying the facet trail based on selections chosen by the customer. (Typically these inputs are taken from the HTTP request query parameters.) From these inputs, it constructs and outputs a new FacetTrail object. You can use standard servlet beans such as ForEach and Switch to read the data from the FacetTrail object and render the facet trail elements on the page.

For example, suppose a site visitor navigates by first selecting the Televisions category, and then selecting the LCD Televisions subcategory. (This assumes that Category is defined as a facet; see the ATG Merchandising User Guide.) Next, she chooses the “$1000 to $2000” selection range for the price facet, and “Acme” as the selection value for the manufacturer facet. The facet trail String might now look something like this:

1:cat444323:1:cat333222:2:1000-2000:32:Acme

In this example, cat444323 is the repository ID of the Televisions category, and cat333222 is the repository ID of the LCD Televisions category. The example also assumes the following facets have been defined in ATG Merchandising:

1 = category
2 = price
32 = manufacturer

The number identifying the facet is the repository ID of the corresponding refinementElement in the refinement repository, which is also used as the ID of the refinementElement XML attribute in the refinement configuration.

Now suppose the site visitor clicks a link to remove the Televisions facet. This sets the removeFacet parameter value to 1:cat444323. When a category selection value is removed from the facet trail, all of that category’s subcategories are also removed, so in this case the LCD Televisions category is removed as well. (In addition, any category-specific facets and selection values that no longer apply are also removed. For example, if the Televisions category has a Screen Size facet associated with it, removing the Televisions facet from the trail also removes the Screen Size facet and selections.)

The new facet trail String is therefore:

2:1000-2000:32:Acme

The displayed results now consist of all products priced between $1000 and $2000 whose manufacturer is Acme. So if Acme also manufactures stereo systems, the ones in this price range will now be displayed.

Last Range Indicator

If a site visitor chooses the last selection range for a facet, the facet trail must indicate this in some way. When a subsequent query is issued to ATG Search, this information is used in constructing the corresponding constraint.

Suppose in the example above the price facet has three selection ranges: $500 to $1000, $2000 to $3000, and $3000 to $4000. If the site visitor selects the $3000 to $4000 range, the facet trail String would look like this:

2:3000-4000|LAST:32:Acme

Note that although |LAST is included in the facet trail String (and therefore may appear in URLs), it is not part of the label for the selection range, and therefore does not appear on the page itself. Also, you do not need to code your JSPs in any special way to deal with this selection range. For example, to remove the $3000 to $4000 selection range, the removeFacet parameter should be set to 2:3000-4000, not 2:3000-4000|LAST.