Algolia addObjects called with empty model data calls api

[mnightingale]

If line 55 is executed we end up calling $index->addObjects([]) which makes a request to Algolia.

scout/src/Engines/AlgoliaEngine.php

Lines 49 to 59 in d5b6913

	$index->addObjects($models->map(function ($model) {
	$array = array_merge(
	$model->toSearchableArray(), $model->scoutMetadata()
	);
	if (empty($array)) {
	return;
	}
	return array_merge(['objectID' => $model->getScoutKey()], $array);
	})->filter()->values()->all());

I'm not sure whether this behaviour should be improved in Scout or algolia/algoliasearch-client-php?

[julienbourdeau]

Hmm that's a good question, I would have said that it should be fixed in Scout but now that I think about it, maybe it makes sense to fix in the client so more people avoid making empty calls 🤔

[driesvints]

Is it though? Doesn't the filter method filter out empty models?

[driesvints]

Going to close this. Please provide a code example on how to reproduce this and I'll take another look.

[mnightingale]

TL;DR: If a models toSearchableArray() returns an empty array the current behaviour in the AlgoliaEngine basically ends up calling the equivalent to collect([null])->filter()->values()->all()which returns [] therefore we call $index->addObjects([]) and a wasteful API request is made to Algolia, since the code filters out empty data I think the intended behaviour was not to call an indexing operation.

PR #318

---

I have a use case where 4,000 models get updated from an external feed several times per hour.
A model may have no changes but I still want to call save() so that the updated_at field gets touched.
Another situation is that not all of the fields that are updated are present in my index, therefore based on several comments in #153 I return [] in toSearchableArray.

I can't call unsearchable() or return false in shouldBeSearchable() because they'll both remove the model from the index which isn't what I want, I just don't want to reindex the model.

public function toSearchableArray()
{
    if (!$this->isDirty('name')) {
        return []; // I don't want to reindex this model but I don't want to remove it
    }

    return [
        'name' => $this->name
    ];
}

The issue is that the update method of the engine will call $index->addObjects([]) and still issue an empty update to Algolia wasting an API request without actually doing anything.

scout/src/Engines/AlgoliaEngine.php

Lines 37 to 60 in fa82a4d

	public function update($models)
	{
	if ($models->isEmpty()) {
	return;
	}
	$index = $this->algolia->initIndex($models->first()->searchableAs());
	if ($this->usesSoftDelete($models->first()) && config('scout.soft_delete', false)) {
	$models->each->pushSoftDeleteMetadata();
	}
	$index->addObjects($models->map(function ($model) {
	$array = array_merge(
	$model->toSearchableArray(), $model->scoutMetadata()
	);
	if (empty($array)) {
	return;
	}
	return array_merge(['objectID' => $model->getScoutKey()], $array);
	})->filter()->values()->all());
	}

I think either it should check if the $models->map(...) call returns an empty array or the Algolia client should check if it receives an empty addObjects request.

Based on these lines, I think it's supposed to handle empty data itself?

scout/src/Engines/AlgoliaEngine.php

Lines 54 to 56 in fa82a4d

	if (empty($array)) {
	return;
	}