Facets Configuration

Facets are the side filters that appear after a search (e.g., "Filter by Year", "Filter by Author"). They allow users to refine a broad search into a specific set of records by grouping results based on common values.

Script: facetas_cnf.php File Created: bases/[db]/opac/[lang]/[db]_facetas.dat

1. How Facets Work

Facets rely on a combination of the Inverted File (Index) for counting and the Master File for display.

• Prerequisite: You cannot create a facet for a field that is not indexed in the database's FST (Field Selection Table).
• Technique: Ideally, fields used for facets should be indexed using Technique 0 (Line).

2. Configuration Columns

The configuration file is a pipe-delimited text file where each line represents a facet box. The interface allows you to define 4 specific columns:

Column	Name	Description	Example
1	Label	The title of the facet box displayed to the user.	Authors
2	Extraction Format	A mini-PFT (ISIS Format) to extract the value from the record. Crucial: Use / at the end to handle repetitive fields correctly.	v100^a/
3	Prefix	The FST prefix used to filter the search when the user clicks a term.	AU_
4	Sort Order	Defines how the terms inside the facet box are sorted. Q: By Quantity (Highest count first). A: Alphabetical order (A-Z).	Q

3. Configuration Example

Below is a typical configuration for a MARC database (marc_facetas.dat).

Place of Publication|v260^a|PA_|Q
Publisher|v260^b|ED_|Q
Year|v260^c|DA_|A
ISBN/ISSN|v20^a|IS_|Q
Personal Author|v100^a/|AU_|Q
Institutional Author|v110^a/|AI_|Q
Title|v245^a|TI_|Q
Subject (Topic)|v650^a/|MA_|Q

Analysis of the Example:

• Row 5 (Personal Author):

• Label: "Personal Author"

• Format: v100^a/ (Extracts subfield ^a. The / ensures that if a book has 3 authors, 3 separate lines are generated).

• Prefix: AU_ (Matches the FST index).

• Sort: Q (Shows the most prolific authors at the top).

• Row 3 (Year):

• Sort: A (Alphabetical/Numerical). This is better for dates, so the years appear as 1990, 1991, 1992, rather than by popularity.

4. Helper: The FST Viewer

To assist you, the configuration script includes a panel at the bottom ("View FST Help").

1. Open the panel to see your [base].fst.
2. Identify the Prefix (e.g., AU_) corresponding to the field you want to facet.
3. Copy that prefix into the 3rd column of your configuration.

Repetitive Fields

If a field is repetitive (like Subjects or Authors), you must include the slash / at the end of the extraction format (e.g., v650^a/). If you omit it, ABCD will concatenate all subjects into a single long string.