DateField.php

<?php

namespace Drupal\datetime\Plugin\migrate\field;

use Drupal\datetime\Plugin\Field\FieldType\DateTimeItemInterface;
use Drupal\migrate\Plugin\MigrationInterface;
use Drupal\migrate\MigrateException;
use Drupal\migrate_drupal\Plugin\migrate\field\FieldPluginBase;

/**
 * Provides a field plugin for date and time fields.
 *
 * @MigrateField(
 *   id = "datetime",
 *   type_map = {
 *     "date" = "datetime",
 *     "datestamp" =  "timestamp",
 *     "datetime" =  "datetime",
 *   },
 *   core = {6,7},
 *   source_module = "date",
 *   destination_module = "datetime"
 * )
 */
class DateField extends FieldPluginBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFieldFormatterMap() {
        return [
            'date_default' => 'datetime_default',
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFieldWidgetMap() {
        return [
            'date' => 'datetime_default',
            'datetime' => 'datetime_default',
            'datestamp' => 'datetime_timestamp',
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function defineValueProcessPipeline(MigrationInterface $migration, $field_name, $data) {
        $to_format = DateTimeItemInterface::DATETIME_STORAGE_FORMAT;
        if (isset($data['field_definition']['data'])) {
            $field_data = unserialize($data['field_definition']['data']);
            if (isset($field_data['settings']['granularity'])) {
                $granularity = $field_data['settings']['granularity'];
                $collected_date_attributes = is_numeric(array_keys($granularity)[0]) ? $granularity : array_keys(array_filter($granularity));
                if (empty(array_intersect($collected_date_attributes, [
                    'hour',
                    'minute',
                    'second',
                ]))) {
                    $to_format = DateTimeItemInterface::DATE_STORAGE_FORMAT;
                }
            }
        }
        switch ($data['type']) {
            case 'date':
                $from_format = 'Y-m-d\\TH:i:s';
                break;
            case 'datestamp':
                $from_format = 'U';
                $to_format = 'U';
                break;
            case 'datetime':
                $from_format = 'Y-m-d H:i:s';
                break;
            default:
                throw new MigrateException(sprintf('Field %s of type %s is an unknown date field type.', $field_name, var_export($data['type'], TRUE)));
        }
        $process = [
            'value' => [
                'plugin' => 'format_date',
                'from_format' => $from_format,
                'to_format' => $to_format,
                'source' => 'value',
            ],
        ];
        $process = [
            'plugin' => 'sub_process',
            'source' => $field_name,
            'process' => $process,
        ];
        $migration->mergeProcessOfProperty($field_name, $process);
    }

}