class Vocabulary

class Vocabulary extends DrupalSqlBase {
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        $query = $this->select('taxonomy_vocabulary', 'v')
            ->fields('v', [
            'vid',
            'name',
            'description',
            'hierarchy',
            'module',
            'weight',
            'machine_name',
        ]);
        return $query;
    }
    
    /**
     * {@inheritdoc}
     */
    public function fields() {
        return [
            'vid' => $this->t('The vocabulary ID.'),
            'name' => $this->t('The name of the vocabulary.'),
            'description' => $this->t('The description of the vocabulary.'),
            'hierarchy' => $this->t('The type of hierarchy allowed within the vocabulary. (0 = disabled, 1 = single, 2 = multiple)'),
            'module' => $this->t('Module responsible for the vocabulary.'),
            'weight' => $this->t('The weight of the vocabulary in relation to other vocabularies.'),
            'machine_name' => $this->t('Unique machine name of the vocabulary.'),
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function prepareRow(Row $row) {
        // If the vocabulary being migrated is the one defined in the
        // 'forum_nav_vocabulary' variable, set the 'forum_vocabulary' source
        // property to true so we know this is the vocabulary used by Forum.
        if ($this->variableGet('forum_nav_vocabulary', 0) == $row->getSourceProperty('vid')) {
            $row->setSourceProperty('forum_vocabulary', TRUE);
        }
        return parent::prepareRow($row);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        $ids['vid']['type'] = 'integer';
        return $ids;
    }

}