{% import 'lib/di.twig' as di %}
<?php

namespace Drupal\{{ machine_name }}\Plugin\views\argument_default;

{% sort %}
use Drupal\Core\Cache\Cache;
use Drupal\Core\Cache\CacheableDependencyInterface;
  {% if configurable %}
use Drupal\Core\Form\FormStateInterface;
  {% endif %}
use Drupal\views\Plugin\views\argument_default\ArgumentDefaultPluginBase;
  {% if services %}
{{ di.use(services) }}
use Symfony\Component\DependencyInjection\ContainerInterface;
  {% endif %}
{% endsort %}

/**
 * {{ plugin_label }} argument default plugin.
 *
 * @ViewsArgumentDefault(
 *   id = "{{ plugin_id }}",
 *   title = @Translation("{{ plugin_label }}")
 * )
 */
class {{ class }} extends ArgumentDefaultPluginBase implements CacheableDependencyInterface {

{% if services %}
{{ di.properties(services) }}

  /**
   * Constructs a new {{ class }} instance.
   *
   * @param array $configuration
   *   The plugin configuration, i.e. an array with configuration values keyed
   *   by configuration option name. The special key 'context' may be used to
   *   initialize the defined contexts by setting it to an array of context
   *   values keyed by context names.
   * @param string $plugin_id
   *   The plugin_id for the plugin instance.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
{{ di.annotation(services) }}
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, {{ di.signature(services) }}) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
{{ di.assignment(services) }}
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
{{ di.container(services) }}
    );
  }

{% endif %}
{% if configurable %}
  /**
   * {@inheritdoc}
   */
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['example'] = ['default' => ''];
    return $options;
  }

  /**
   * {@inheritdoc}
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    $form['example'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Example'),
      '#default_value' => $this->options['example'],
    ];
  }

{% endif %}
  /**
   * {@inheritdoc}
   */
  public function getArgument() {

    // @DCG
    // Here is the place where you should create a default argument for the
    // contextual filter. The source of this argument depends on your needs.
    // For example, you can extract the value from the URL or fetch it from
    // some fields of the current viewed entity.
    $argument = 123;

    return $argument;
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheMaxAge() {
    return Cache::PERMANENT;
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheContexts() {
    // @DCG Use 'url' context if the argument comes from URL.
    return [];
  }

}