dmeblog_migrate.module

<?php

/**
 * @file
 * Contains dmeblog_migrate.module..
 */

use Drupal\migrate\Plugin\MigrateSourceInterface;
use Drupal\migrate\Plugin\MigrationInterface;
use Drupal\migrate\Row;
use Drupal\migrate\MigrateSkipRowException;

/**
 * Implements hook_migrate_prepare_row().
 *
 * This function will be called once, for every row, in every migration. Which
 * makes it quite powerful.
 *
 * It's also important to use some smart logic in this function to ensure you're
 * only performing your extra logic when it's really needed. Not doing so has
 * the potential to really slow things down.
 *
 * We recommend at a minimum always checking the $migration->id() value to see
 * which migration is currently being executed.
 */
function dmeblog_migrate_migrate_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
  // This example performs some extra processing when running the
  // upgrade_d7_field migration. In this case we only want to migrate the fields
  // that are used by our Drupal 7 blog_post content type, and not all the
  // fields defined on our Drupal 7 site. So for each row in the Drupal 7 fields
  // list we compare it against a static list and tell the Migrate API to skip
  // any that are not in our list.
  if ($migration->id() == 'dmeblog_d7_field' || $migration->id() == 'dmeblog_d7_field_instance') {
    // Drupal 7 field names for all the fields we know we DO want to migrate.
    $blog_fields = [
      'field_blog_post_images',
      'field_blog_post_files',
      'field_planet',
      'taxonomy_blog_tags',
    ];

    // The `field_name` property here comes from the source plugin which defines
    // the list of source fields.
    // @see \Drupal\field\Plugin\migrate\source\d7\Field::fields()
    if (!in_array($row->getSourceProperty('field_name'), $blog_fields)) {
      // Skip this row by throwing a new MigrateSkipRowException exception.
      // Using FALSE here also instructs the Migrate API to forgo creating an
      // entry in the map table for this particular record instead of marking
      // it as ignored. Either would work in this case, this method works for us
      // since don't really need to record that it was STATUS_IGNORED for any
      // reason.
      throw new MigrateSkipRowException('', TRUE);
    }
  }
}

/**
 * Implements hook_migrate_MIGRATION_ID_prepare_row().
 *
 * The migration we're processing in this place is "dmeblog_d7_node_type".
 */
function dmeblog_migrate_migrate_dmeblog_d7_node_type_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
  // Skip all node types that are no in our list.
  $node_types = ['blog_post'];
  if (!in_array($row->getSourceProperty('type'), $node_types)) {
    throw new MigrateSkipRowException('', TRUE);
  }
}