Indexing latitude/longitude field

Thanks! Your patch is working for me also.

Patch #4 was added to the project more than a year ago and has been working well ever since. Thank you for your work.

1. We should ensure that $value is not empty and string as it is required by strpos() and explode().

  // Ensure the value is a non-empty string.
  if (empty($value) || !is_string($value)) {
    throw new \InvalidArgumentException('The provided value must be a non-empty string.');
  }

2. Variable $lat_lon_split in empty() always exists and is not falsy. (PHPStan error)

if (!empty($lat_lon_split) && isset($lat_lon_split[0]) && isset($lat_lon_split[1]))

could be simplified with:

if (count($lat_lon_split) === 2) 

3. Uppercase for boolean: false -> FALSE
4. I'd change plugin id: geolocation_algolia to specify that this is Geo location.

Rerolled patch #4 to be applicable to 3.0.x. Also renamed data type from location_algolia to geolocation_algolia.

Phpstan returns
Line src/Plugin/search_api/data_type/GeolocationAlgoliaDataType.php
------ ----------------------------------------------------------------------------------
17 Class
Drupal\search_api_algolia\Plugin\search_api\data_type\GeolocationAlgoliaDataType
extends unknown class Drupal\search_api\DataType\DataTypePluginBase.
💡 Learn more at https://phpstan.org/user-guide/discovering-symbols

That might be fixed with adding drupal/search_api to the composer.json.