[Question] how to include custom attributes in Eloquent model of search results

[freeku]

Does anyone know how to include custom attributes from the index into the model when returning search results?

I've added custom fields in the index using toSearchableArray and these are showing up when returning the raw results. However, when I use the ->get(), the custom fields are not included in the model objects (as they are not in the underlying database table), and I can't seem to find out how to include them.

[ametad]

Two options:

Eloquent accessor

https://laravel.com/docs/8.x/eloquent-mutators#defining-an-accessor

When you can generate / build up the data again on runtime, just do so with an accessor in an Eloquent model. Now you have the data again from the model.

Implement your own EloquentHitsIteratorAggregate

Or, you enrich the model with your own EloquentHitsIteratorAggregate class. This is described here: #28

I use this to include the _score and highlight, that Elasticsearch gave back, unto the model. Like so:

class EloquentHitsIteratorAggregate implements IteratorAggregate
{
    /**
     * @var array
     */
    private $results;
    /**
     * @var callable|null
     */
    private $callback;

    /**
     * @param array $results
     * @param callable|null $callback
     */
    public function __construct(array $results, callable $callback = null)
    {
        $this->results = $results;
        $this->callback = $callback;
    }

    /**
     * @inheritDoc
     */
    public function getIterator()
    {
        if (! $this->results['hits']['total']) {
            return new \ArrayIterator(collect());
        }

        /** @var Collection $models */
        $models = collect($this->results['hits']['hits'])->groupBy('_source.__class_name')
            ->map(function ($results, $class) {
                $model = new $class;
                $builder = new Builder($model, '');
                if (!empty($this->callback)) {
                    $builder->query($this->callback);
                }

                /* @var Searchable $model */
                return $model->getScoutModelsByIds(
                    $builder, $results->pluck('_id')->all()
                );
            })
            ->flatten()->keyBy(function ($model) {
                return get_class($model).'::'.$model->getScoutKey();
            });

        /** @var Collection $hits */
        $hits = collect($this->results['hits']['hits'])->map(function ($hit) use ($models) {
            $key = $hit['_source']['__class_name'].'::'.$hit['_id'];

            if (!isset($models[$key])) {
                return null;
            }

            $model = $models[$key];

            // Enrich the model with data from Elasticsearch
            $model->_score = $hit['_score'];
            $model->_highlight = $hit['highlight'] ?? null;

            return $model;

        })->filter()->all();

        return new \ArrayIterator($hits);
    }
}

[ametad]

PS. You can implement your own class by binding it in the ioc. This can be done in AppServiceProvider::register():

        $this->app->bind(
            'Matchish\ScoutElasticSearch\ElasticSearch\HitsIteratorAggregate',
            'App\Elasticsearch\EloquentHitsIteratorAggregate'
        );

[freeku]

Great, thanks for the extensive reply @ametad! I've been able to add the required fields, thanks!