TermTranslation.php

<?php

namespace Drupal\taxonomy\Plugin\migrate\source\d7;

use Drupal\content_translation\Plugin\migrate\source\I18nQueryTrait;
use Drupal\migrate\Row;

/**
 * Gets i18n taxonomy terms from source database.
 *
 * @MigrateSource(
 *   id = "d7_taxonomy_term_translation",
 *   source_module = "i18n_taxonomy"
 * )
 */
class TermTranslation extends Term {
    use I18nQueryTrait;
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        $query = parent::query();
        if ($this->database
            ->schema()
            ->fieldExists('taxonomy_term_data', 'language')) {
            $query->addField('td', 'language', 'td_language');
        }
        if ($this->database
            ->schema()
            ->fieldExists('taxonomy_vocabulary', 'i18n_mode')) {
            $query->addField('tv', 'i18n_mode');
        }
        return $query;
    }
    
    /**
     * {@inheritdoc}
     */
    public function prepareRow(Row $row) {
        parent::prepareRow($row);
        $row->setSourceProperty('language', $row->getSourceProperty('td_language'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function fields() {
        $fields = [
            'language' => $this->t('Language for this term.'),
            'name_translated' => $this->t('Term name translation.'),
            'description_translated' => $this->t('Term description translation.'),
        ];
        return parent::fields() + $fields;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        $ids['language']['type'] = 'string';
        $ids['language']['alias'] = 'td';
        return parent::getIds() + $ids;
    }

}