edlp_d8/core/modules/dblog/dblog.module

<?php

/**
 * @file
 * System monitoring and logging for administrators.
 *
 * The Database Logging module monitors your site and keeps a list of recorded
 * events containing usage and performance data, errors, warnings, and similar
 * operational information.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\views\ViewEntityInterface;
use Drupal\views\ViewExecutable;

/**
 * Implements hook_help().
 */
function dblog_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.dblog':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The Database Logging module logs system events in the Drupal database. For more information, see the <a href=":dblog">online documentation for the Database Logging module</a>.', [':dblog' => 'https://www.drupal.org/documentation/modules/dblog']) . '</p>';
      $output .= '<h3>' . t('Uses') . '</h3>';
      $output .= '<dl>';
      $output .= '<dt>' . t('Monitoring your site') . '</dt>';
      $output .= '<dd>' . t('The Database Logging module allows you to view an event log on the <a href=":dblog">Recent log messages</a> page. The log is a chronological list of recorded events containing usage data, performance data, errors, warnings and operational information. Administrators should check the log on a regular basis to ensure their site is working properly.', [':dblog' => \Drupal::url('dblog.overview')]) . '</dd>';
      $output .= '<dt>' . t('Debugging site problems') . '</dt>';
      $output .= '<dd>' . t('In case of errors or problems with the site, the <a href=":dblog">Recent log messages</a> page can be useful for debugging, since it shows the sequence of events. The log messages include usage information, warnings, and errors.', [':dblog' => \Drupal::url('dblog.overview')]) . '</dd>';
      $output .= '</dl>';
      return $output;

    case 'dblog.overview':
      return '<p>' . t('The Database Logging module logs system events in the Drupal database. Monitor your site or debug site problems on this page.') . '</p>';
  }
}

/**
 * Implements hook_menu_links_discovered_alter().
 */
function dblog_menu_links_discovered_alter(&$links) {
  if (\Drupal::moduleHandler()->moduleExists('search')) {
    $links['dblog.search'] = [
      'title' => new TranslatableMarkup('Top search phrases'),
      'route_name' => 'dblog.search',
      'description' => new TranslatableMarkup('View most popular search phrases.'),
      'parent' => 'system.admin_reports',
    ];
  }

  return $links;
}

/**
 * Implements hook_cron().
 *
 * Controls the size of the log table, paring it to 'dblog_row_limit' messages.
 */
function dblog_cron() {
  // Cleanup the watchdog table.
  $row_limit = \Drupal::config('dblog.settings')->get('row_limit');

  // For row limit n, get the wid of the nth row in descending wid order.
  // Counting the most recent n rows avoids issues with wid number sequences,
  // e.g. auto_increment value > 1 or rows deleted directly from the table.
  if ($row_limit > 0) {
    $min_row = db_select('watchdog', 'w')
      ->fields('w', ['wid'])
      ->orderBy('wid', 'DESC')
      ->range($row_limit - 1, 1)
      ->execute()->fetchField();

    // Delete all table entries older than the nth row, if nth row was found.
    if ($min_row) {
      db_delete('watchdog')
        ->condition('wid', $min_row, '<')
        ->execute();
    }
  }
}

/**
 * Gathers a list of uniquely defined database log message types.
 *
 * @return array
 *   List of uniquely defined database log message types.
 */
function _dblog_get_message_types() {
  return db_query('SELECT DISTINCT(type) FROM {watchdog} ORDER BY type')
    ->fetchAllKeyed(0, 0);
}

/**
 * Implements hook_form_FORM_ID_alter() for system_logging_settings().
 */
function dblog_form_system_logging_settings_alter(&$form, FormStateInterface $form_state) {
  $row_limits = [100, 1000, 10000, 100000, 1000000];
  $form['dblog_row_limit'] = [
    '#type' => 'select',
    '#title' => t('Database log messages to keep'),
    '#default_value' => \Drupal::configFactory()->getEditable('dblog.settings')->get('row_limit'),
    '#options' => [0 => t('All')] + array_combine($row_limits, $row_limits),
    '#description' => t('The maximum number of messages to keep in the database log. Requires a <a href=":cron">cron maintenance task</a>.', [':cron' => \Drupal::url('system.status')]),
  ];

  $form['#submit'][] = 'dblog_logging_settings_submit';
}

/**
 * Form submission handler for system_logging_settings().
 *
 * @see dblog_form_system_logging_settings_alter()
 */
function dblog_logging_settings_submit($form, FormStateInterface $form_state) {
  \Drupal::configFactory()->getEditable('dblog.settings')->set('row_limit', $form_state->getValue('dblog_row_limit'))->save();
}

/**
 * Implements hook_ENTITY_TYPE_presave() for views entities.
 *
 * This hook ensures there are no views based that are using a wrong plugin for
 * wid and uid fields on views that use watchdog as base table.
 *
 * @deprecated in Drupal 8.4.x and will be removed before 9.0.0.
 *
 * @see https://www.drupal.org/node/2876378
 */
function dblog_view_presave(ViewEntityInterface $view) {
  // Only interested in watchdog based views.
  if ($view->get('base_table') != 'watchdog') {
    return;
  }

  $displays = $view->get('display');
  $update = FALSE;
  foreach ($displays as $display_name => $display) {

    // Iterate through all the fields of watchdog views based tables.
    if (isset($display['display_options']['fields'])) {
      foreach ($display['display_options']['fields'] as $field_name => $field) {
        // We are only interested in wid and uid fields from the watchdog table
        // that still use the numeric id.
        if (isset($field['table']) &&
            $field['table'] === 'watchdog' &&
            $field['plugin_id'] == 'numeric' &&
            in_array($field['field'], ['wid', 'uid'], TRUE)) {

          $displays[$display_name]['display_options']['fields'][$field_name]['plugin_id'] = 'standard';

          // Delete all the attributes related to numeric fields.
          unset(
            $displays[$display_name]['display_options']['fields'][$field_name]['set_precision'],
            $displays[$display_name]['display_options']['fields'][$field_name]['precision'],
            $displays[$display_name]['display_options']['fields'][$field_name]['decimal'],
            $displays[$display_name]['display_options']['fields'][$field_name]['separator'],
            $displays[$display_name]['display_options']['fields'][$field_name]['format_plural'],
            $displays[$display_name]['display_options']['fields'][$field_name]['format_plural_string'],
            $displays[$display_name]['display_options']['fields'][$field_name]['prefix'],
            $displays[$display_name]['display_options']['fields'][$field_name]['suffix']
          );

          $update = TRUE;
          @trigger_error("The numeric plugin for watchdog.$field_name field is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Must use standard plugin instead. See https://www.drupal.org/node/2876378.", E_USER_DEPRECATED);
        }
      }
    }

    // Iterate all filters looking for type filters to update.
    if (isset($display['display_options']['filters'])) {
      foreach ($display['display_options']['filters'] as $filter_name => $filter) {
        if (isset($filter['table']) &&
            $filter['table'] === 'watchdog' &&
            $filter['plugin_id'] == 'in_operator' &&
            $filter['field'] == 'type') {

          $displays[$display_name]['display_options']['filters'][$filter_name]['plugin_id'] = 'dblog_types';
          $update = TRUE;
          @trigger_error("The in_operator plugin for watchdog.type filter is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Must use dblog_types plugin instead. See https://www.drupal.org/node/2876378.", E_USER_DEPRECATED);
        }
      }
    }
  }

  if ($update) {
    $view->set('display', $displays);
  }
}

/**
 * Implements hook_views_pre_render().
 */
function dblog_views_pre_render(ViewExecutable $view) {
  if (isset($view) && ($view->storage->get('base_table') == 'watchdog')) {
    $view->element['#attached']['library'][] = 'dblog/drupal.dblog';
  }
}