lutece-lucene-indexer

# Lutece 8 Search Indexer

> Before implementing a search indexer, consult `~/.lutece-references/lutece-form-plugin-forms/src/java/fr/paris/lutece/plugins/forms/service/search/` — the reference implementation.

## Architecture Overview

```
IMyPluginSearchIndexer (interface)
    ↑ implements
LuceneMyPluginSearchIndexer (@ApplicationScoped, owns its Lucene index)
    ↓ triggered by
MyPluginSearchDaemon (declared in plugin.xml)
    ↓ fed by
EventListener (@ObservesAsync domain events → queues IndexerAction)
```

A plugin manages its own Lucene index independently from the core. This allows custom fields, sorting, filtering and dedicated search UI in the back-office.

## Step 1 — Indexer Interface

```java
public interface IEntitySearchIndexer
{
    /**
     * Index a single document (queues an action for the daemon)
     */
    void indexDocument( int nIdEntity, int nIdTask, Plugin plugin );

    /**
     * Add an indexer action to the queue
     */
    void addIndexerAction( int nIdEntity, int nIdTask, Plugin plugin );

    /**
     * Process queued actions (called by daemon)
     */
    String incrementalIndexing( );

    /**
     * Rebuild the entire index (called by daemon on flag)
     */
    String fullIndexing( );

    /**
     * Check if index is ready
     */
    boolean isIndexerInitialized( );
}
```

## Step 2 — Lucene Indexer Implementation

```java
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Inject;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.IntPoint;
import org.apache.lucene.document.LongPoint;
import org.apache.lucene.document.NumericDocValuesField;
import org.apache.lucene.document.SortedDocValuesField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.util.BytesRef;

import fr.paris.lutece.portal.service.search.SearchItem;

@Application