knowledge-8.x-1.x-dev/src/Plugin/views/field/CompetencyPercentage.php

<?php

namespace Drupal\knowledge\Plugin\views\field;

use Drupal\Core\Form\FormStateInterface;
use Drupal\user\Entity\Role;
use Drupal\views\Plugin\views\field\FieldPluginBase;
use Drupal\views\ResultRow;

/**
 * Field handler to present the name of the last comment poster.
 *
 * @ingroup views_field_handlers
 *
 * @ViewsField("knowledge_competency_percentage")
 */
class CompetencyPercentage extends FieldPluginBase {

  /**
   * The role field prefix.
   *
   * @var string
   */
  protected $prefix;

  /**
   * {@inheritdoc}
   */
  public function query() {

    $this->ensureMyTable();
    $scope = $this->options['scope'];

    switch ($scope) {
      case 3:
        $prefix = 'publisher_';
        break;

      case 2:
        $prefix = 'contributor_';
        break;

      case 1:
        $prefix = 'candidate_';
        break;

      case 0:
      default:
        $prefix = '';
        break;
    }

    $correct = $prefix . 'correct';
    $total = $prefix . 'total';
    $this->prefix = $prefix;
    /** @var \Drupal\views\Plugin\views\query\Sql $query */
    $query = $this->query;
    $query->addField(NULL, "(\"$this->tableAlias\".\"$correct\" / \"$this->tableAlias\".\"$total\")", $this->tableAlias . '_' . $prefix . $this->field);
  }

  /**
   * {@inheritdoc}
   */
  public function render(ResultRow $values) {

    $prefix = $this->prefix;
    $field = $this->tableAlias . '_' . $prefix . $this->field;
    $percent = $values->$field * 100;

    return $this->sanitizeValue($percent . '%');
  }

  /**
   * {@inheritdoc}
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {

    $candidate = Role::load('knowledge_candidate');
    $contributor = Role::load('knowledge_contributor');
    $publisher = Role::load('knowledge_publisher');
    $form['scope'] = [
      '#type' => 'radios',
      '#title' => $this->t('Scope'),
      '#default_value' => $this->options['scope'],
      '#options' => [
        0 => $this->t('Total'),
        1 => $candidate->label(),
        2 => $contributor->label(),
        3 => $publisher->label(),
      ],
    ];

    parent::buildOptionsForm($form, $form_state);
  }

  /**
   * {@inheritdoc}
   */
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['scope'] = [
      'default' => 0,
    ];

    return $options;
  }

}