Alphabetic indexes

The Alphabetic indexes module allows users to navigate the database through sorted lists of terms (Indices). This is distinct from searching; it reads directly from the Inverted File keys.

Script: alpha_ix.php File Created: bases/[db]/opac/[lang]/[db].ix

1. How it Works

This configuration defines which buttons appear below the Free Search form.

When a user clicks on one of these buttons (e.g., "Authors"), the system opens a browsing window (dictionary) that scans the index keys starting with the selected prefix.

2. Configuration Parameters

The interface manages a mapping table defined by the following columns:

Field	Description	Technical Detail
Label	The name of the index button (e.g., "Authors").	User-facing string.
Prefix	The internal FST prefix (e.g., AU_).	Must match the [db].fst exactly.
Columns	Defines the layout of the index window. 1: Single column. 2: Two columns. Empty: The index is hidden/disabled.	Visual setting.
Postings	If set to ALL, shows the count of records for each term.	Example: Shakespeare (15)

3. Example Configuration

The system writes these settings to the [db].ix file using the pipe (|) separator.

Example marc.ix File

Title|TI_|1|ALL
Author|AU_|1|ALL
Subject|SU_|1|ALL

• Line 1: Creates a "Title" button that browses the TI_ index, displayed in 1 column, showing record counts.

4. The FST Helper

To configure this correctly, you must know the Prefixes defined in your database.

1. Click the "View FST" accordion at the bottom of the page.
2. The system reads bases/[db]/data/[db].fst.
3. Identify the prefixes (e.g., look for lines like 10 0 "AU_"v10).
4. Copy the AU_ prefix to the configuration form.

Case Sensitivity

The prefixes are case-sensitive. If your FST uses TI_ (uppercase), entering ti_ (lowercase) here will result in an empty list for the user.

---

5. Integration with "Did You Mean?"

The configuration you define here plays a crucial role in the Spell Checking mechanism.

When generating the static dictionary for the "Did you mean?" feature, the system allows you to use these exact rules to filter the content.

• Benefit: Instead of exporting the entire index (which includes IDs, timestamps, and internal codes), you can generate a clean dictionary containing only the terms from the fields defined above (e.g., only Titles, Authors, and Subjects).

To manage the dictionary file and generate it, refer to the Dictionary & Spell Checker documentation.