DblogFilterForm.php

<?php

namespace Drupal\dblog\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Provides the database logging filter form.
 *
 * @internal
 */
class DblogFilterForm extends FormBase {

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'dblog_filter_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $filters = dblog_filters();
    $form['filters'] = [
      '#type' => 'details',
      '#title' => $this
        ->t('Filter log messages'),
      '#open' => TRUE,
    ];
    $session_filters = $this
      ->getRequest()
      ->getSession()
      ->get('dblog_overview_filter', []);
    foreach ($filters as $key => $filter) {
      $form['filters']['status'][$key] = [
        '#title' => $filter['title'],
        '#type' => 'select',
        '#multiple' => TRUE,
        '#size' => 8,
        '#options' => $filter['options'],
      ];
      if (!empty($session_filters[$key])) {
        $form['filters']['status'][$key]['#default_value'] = $session_filters[$key];
      }
    }
    $form['filters']['actions'] = [
      '#type' => 'actions',
      '#attributes' => [
        'class' => [
          'container-inline',
        ],
      ],
    ];
    $form['filters']['actions']['submit'] = [
      '#type' => 'submit',
      '#value' => $this
        ->t('Filter'),
    ];
    if (!empty($session_filters)) {
      $form['filters']['actions']['reset'] = [
        '#type' => 'submit',
        '#value' => $this
          ->t('Reset'),
        '#limit_validation_errors' => [],
        '#submit' => [
          '::resetForm',
        ],
      ];
    }
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
    if ($form_state
      ->isValueEmpty('type') && $form_state
      ->isValueEmpty('severity')) {
      $form_state
        ->setErrorByName('type', $this
        ->t('You must select something to filter by.'));
    }
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $filters = dblog_filters();
    $session_filters = $this
      ->getRequest()
      ->getSession()
      ->get('dblog_overview_filter', []);
    foreach ($filters as $name => $filter) {
      if ($form_state
        ->hasValue($name)) {
        $session_filters[$name] = $form_state
          ->getValue($name);
      }
    }
    $this
      ->getRequest()
      ->getSession()
      ->set('dblog_overview_filter', $session_filters);
  }

  /**
   * Resets the filter form.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function resetForm(array &$form, FormStateInterface $form_state) {
    $this
      ->getRequest()
      ->getSession()
      ->remove('dblog_overview_filter');
  }

}