For Developers

Each section of a Sentinel assessment comes from a provider plugin. Add your own to show more information about a location, such as air quality, river gauges, school closures or road conditions.

Providers

Sentinel ships with these providers, run lightest first:

Site builders can turn any provider off in Sentinel's settings.

Writing a provider

namespace Drupal\mymodule\Plugin\SentinelProvider;

use Drupal\Core\Plugin\PluginBase;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\sentinel\Assessment;
use Drupal\sentinel\Attribute\SentinelProvider;
use Drupal\sentinel\SentinelProviderInterface;

#[SentinelProvider(
  id: 'air_quality',
  label: new TranslatableMarkup('Air quality'),
  weight: 12,
)]
class AirQualityProvider extends PluginBase implements SentinelProviderInterface {

  public function assess(Assessment $assessment): void {
    // Look up data for $assessment->point (latitude, longitude). Earlier
    // providers have set $assessment->place, ->floodZone and ->alerts.
    // Add a note if a service is down:
    // $assessment->notes[] = 'Air quality could not be checked.';
  }

  public function build(Assessment $assessment): array {
    return ['#markup' => '<h3>Air quality</h3>...'];
  }

}

Use ContainerFactoryPluginInterface for services. Cache lookups by $assessment->point->rounded()->key() so nearby visitors share them. Return [] from build() to show nothing.

Services

Services can also be autowired by class.

Templates

• sentinel-assessment.html.twig: the banner, place, sections, notes and disclaimer.
• sentinel-alerts.html.twig: the alert list.
• sentinel-advice.html.twig: what to do.

Alert text is plain text from the official source and is escaped by Twig. Keep it unchanged when theming.

Cache tag

sentinel_alerts is invalidated whenever stored alerts change. Add it to anything you build from alerts.