Usage

To keep a model's related records in sync, add the HasSearchableRelations trait to it. Then add a searchableRelations() method that lists the names of the relationships you want to watch.

use Foxws\ScoutRelations\Concerns\HasSearchableRelations;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;

class Author extends Model
{
    use HasSearchableRelations;

    /**
     * Relationships whose models should be re-indexed when this model changes.
     *
     * @return array<int, string>
     */
    public function searchableRelations(): array
    {
        return ['posts'];
    }

    public function posts(): HasMany
    {
        return $this->hasMany(Post::class);
    }
}

The related model — Post in this example — must use Laravel Scout's own Searchable trait, just like any other searchable model:

use Illuminate\Database\Eloquent\Model;
use Laravel\Scout\Searchable;

class Post extends Model
{
    use Searchable;

    public function toSearchableArray(): array
    {
        return [
            'id'          => $this->id,
            'title'       => $this->title,
            'author_name' => $this->author->name, // kept fresh on every re-index
        ];
    }
}

With this in place, saving an Author with changes, or deleting one, automatically re-indexes all of that author's Post records.

How it works

The HasSearchableRelations trait listens to two Eloquent model events:

Related records are re-indexed in chunks, using chunkById. If the related model defines its own makeAllSearchableUsing() method, that method is used while building each chunk, which avoids extra N+1 queries.

The package also guards against infinite loops: if two models watch each other's relationships, a re-index on one side won't keep triggering the other back and forth forever.