class RdfMapping

class RdfMapping extends DrupalSqlBase {
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        return $this->select('rdf_mapping', 'r')
            ->fields('r');
    }
    
    /**
     * {@inheritdoc}
     */
    public function prepareRow(Row $row) {
        $field_mappings = [];
        foreach (unserialize($row->getSourceProperty('mapping')) as $field => $mapping) {
            if ($field === 'rdftype') {
                $row->setSourceProperty('types', $mapping);
            }
            else {
                $field_mappings[$field] = $mapping;
            }
        }
        $row->setSourceProperty('fieldMappings', $field_mappings);
        return parent::prepareRow($row);
    }
    
    /**
     * {@inheritdoc}
     */
    public function fields() {
        return [
            'type' => $this->t('The name of the entity type a mapping applies to (node, user, comment, etc.)'),
            'bundle' => $this->t('The name of the bundle a mapping applies to.'),
            'mapping' => $this->t('The serialized mapping of the bundle type and fields to RDF terms.'),
            'types' => $this->t('RDF types.'),
            'fieldMappings' => $this->t('RDF field mappings.'),
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        return [
            'type' => [
                'type' => 'string',
            ],
            'bundle' => [
                'type' => 'string',
            ],
        ];
    }

}