own FilterFormat source plugin, source: \Drupal\filter\Plugin\migrate\source\d6\FilterFormat

src/Plugin/migrate/source/d5/FilterFormat.php

+<?php
+
+namespace Drupal\migrate_drupal_d5\Plugin\migrate\source\d5;
+
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+use Drupal\migrate\Row;
+
+/**
+ * Drupal 5 filter source from database.
+ *
+ * For available configuration keys, refer to the parent classes.
+ *
+ * @see \Drupal\migrate\Plugin\migrate\source\SqlBase
+ * @see \Drupal\migrate\Plugin\migrate\source\SourcePluginBase
+ * @see \Drupal\filter\Plugin\migrate\source\d6\FilterFormat
+ *
+ * @MigrateSource(
+ *   id = "d5_filter_format",
+ *   source_module = "filter"
+ * )
+ */
+class FilterFormat extends DrupalSqlBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    return $this->select('filter_formats', 'f')->fields('f');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fields() {
+    return [
+      'format' => $this->t('Format ID.'),
+      'name' => $this->t('The name of the format.'),
+      'cache' => $this->t('Whether the format is cacheable.'),
+      'roles' => $this->t('The role IDs which can use the format.'),
+      'filters' => $this->t('The filters configured for the format.'),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function prepareRow(Row $row) {
+    $filters = [];
+    $roles = $row->getSourceProperty('roles');
+    $row->setSourceProperty('roles', array_values(array_filter(explode(',', $roles))));
+    $format = $row->getSourceProperty('format');
+    // Find filters for this row.
+    $results = $this->select('filters', 'f')
+      ->fields('f', ['module', 'delta', 'weight'])
+      ->condition('format', $format)
+      ->execute();
+    foreach ($results as $raw_filter) {
+      $module = $raw_filter['module'];
+      $delta = $raw_filter['delta'];
+      $filter = [
+        'module' => $module,
+        'delta' => $delta,
+        'weight' => $raw_filter['weight'],
+        'settings' => [],
+      ];
+      // Load the filter settings for the filter module, modules can use
+      // hook_migration_d6_filter_formats_prepare_row() to add theirs.
+      if ($raw_filter['module'] == 'filter') {
+        if (!$delta) {
+          if ($setting = $this->variableGet("allowed_html_$format", NULL)) {
+            $filter['settings']['allowed_html'] = $setting;
+          }
+          if ($setting = $this->variableGet("filter_html_help_$format", NULL)) {
+            $filter['settings']['filter_html_help'] = $setting;
+          }
+          if ($setting = $this->variableGet("filter_html_nofollow_$format", NULL)) {
+            $filter['settings']['filter_html_nofollow'] = $setting;
+          }
+        }
+        elseif ($delta == 3 && ($setting = $this->variableGet("filter_url_length_$format", NULL))) {
+          $filter['settings']['filter_url_length'] = $setting;
+        }
+      }
+      $filters[] = $filter;
+    }
+
+    $row->setSourceProperty('filters', $filters);
+    return parent::prepareRow($row);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIds() {
+    $ids['format']['type'] = 'integer';
+    return $ids;
+  }
+
+}