[TYPO3] Migration of tt_news to tx_news

The extension migration is a small Swiss army knife in the TYPO3 area. In addition to the option of exporting and importing entire page trees on the CLI, the extension also offers the option of migrating within the existing database. The documentation on GitHub has some helpful tips here.

However, this blog post is only about news migration. We have already switched a handful of older projects from tt_news to tx_news in the past and I have made the classes used available to you here. If you need them, you can use them directly.

Note: Over time there have been different variants of tt_news and of course also of tx_news. So you may have to lend a hand at one point or another. However, we hope that the code will still help you - maybe see it as a kind of kickstarter.

1. Main Configuration

File EXT:migration_extend/Configuration/Migration.php:

<?php
return [
    // Default values if not given from CLI
    'configuration' => [
        'key' => '',
        'dryrun' => true,
        'limitToRecord' => null,
        'limitToPage' => 583,
        'recursive' => true
    ],

    // Define your migrations
    'migrations' => [
        [
            'className' => \In2code\MigrationExtend\Migration\Importer\NewsCategoriesImporter::class,
            'keys' => [
                'news',
                'categories',
                'categoriesimport'
            ]
        ],
        [
            'className' => \In2code\MigrationExtend\Migration\Migrator\CategoriesMigrator::class,
            'keys' => [
                'news',
                'categories',
                'categoriesmigration'
            ]
        ],
        [
            'className' => \In2code\MigrationExtend\Migration\Importer\NewsImporter::class,
            'keys' => [
                'news'
            ]
        ],
        [
            'className' => \In2code\MigrationExtend\Migration\Migrator\NewsMigrator::class,
            'keys' => [
                'news'
            ]
        ],
        [
            'className' => \In2code\MigrationExtend\Migration\Migrator\ContentMigrator::class,
            'keys' => [
                'content'
            ]
        ]
    ]
];

File EXT:migration_extend/ext_tables.sql

CREATE TABLE tx_news_domain_model_news (
    _migrated tinyint(4) unsigned DEFAULT '0' NOT NULL,
    _migrated_uid int(11) unsigned DEFAULT '0' NOT NULL,
    _migrated_table varchar(255) DEFAULT '' NOT NULL,
    _migrated_twice tinyint(4) unsigned DEFAULT '0' NOT NULL
);
CREATE TABLE sys_category (
    _migrated tinyint(4) unsigned DEFAULT '0' NOT NULL,
    _migrated_uid int(11) DEFAULT '0' NOT NULL,
    _migrated_table varchar(255) DEFAULT '' NOT NULL,
    _migrated_twice tinyint(4) unsigned DEFAULT '0' NOT NULL
);

File EXT:migration_extend/ext_localconf.php:

<?php
if (!defined('TYPO3_MODE')) {
    die('Access denied.');
}

call_user_func(
    function () {
        /**
         * Fluid Namespace
         */
        $GLOBALS['TYPO3_CONF_VARS']['SYS']['fluid']['namespaces']['migrationextend'][]
            = 'In2code\MigrationExtend\ViewHelpers';
    }
);

2. Importers

File EXT:migration_extend/Classes/Migration/Importer/NewsImporter.php (Basic import of news records):

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\Importer;

use In2code\Migration\Migration\Importer\AbstractImporter;
use In2code\Migration\Migration\Importer\ImporterInterface;

/**
 * Class NewsImporter
 */
class NewsImporter extends AbstractImporter implements ImporterInterface
{

    /**
     * @var string
     */
    protected $tableName = 'tx_news_domain_model_news';

    /**
     * @var string
     */
    protected $tableNameOld = 'tt_news';

    /**
     * @var bool
     */
    protected $truncate = false;

    /**
     * @var bool
     */
    protected $keepIdentifiers = false;

    /**
     * @var array
     */
    protected $mapping = [
        'type' => 'type',
        'title' => 'title',
        'short' => 'teaser',
        'bodytext' => 'bodytext',
        'datetime' => 'datetime',
        'author' => 'author',
        'author_email' => 'author_email',
        'keyword' => 'keywords',
        'archivedate' => 'archive',
        'editlock' => 'editlock',
        'keywords' => 'keywords',
        'page' => 'internalurl',
        'ext_url' => 'externalurl',
        'hidden' => 'hidden',

        'fe_group' => 'fe_group',
        'sys_language_uid' => 'sys_language_uid',
        'l18n_parent' => 'l10n_parent',
        'l18n_diffsource' => 'l10n_diffsource',

        'category' => 'categories',
    ];
}

File EXT:migration_extend/Classes/Migration/Importer/NewsCategoriesImporter.php (Basic import of news categories):

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\Importer;

use In2code\Migration\Migration\Importer\AbstractImporter;
use In2code\Migration\Migration\Importer\ImporterInterface;
use In2code\MigrationExtend\Migration\PropertyHelpers\CreateSortingNumberFromPropertyPropertyHelper;

/**
 * Class NewsCategoriesImporter
 */
class NewsCategoriesImporter extends AbstractImporter implements ImporterInterface
{
    /**
     * Table name where to migrate to
     *
     * @var string
     */
    protected $tableName = 'sys_category';

    /**
     * Table name from migrate to
     *
     * @var string
     */
    protected $tableNameOld = 'tt_news_cat';

    /**
     * @var bool
     */
    protected $truncate = false;

    /**
     * @var bool
     */
    protected $keepIdentifiers = false;

    /**
     * @var array
     */
    protected $mapping = [
        'pid' => 'pid',
        'title' => 'title',
        'parent_category' => 'parent',
        'fe_group' => 'fe_group',
        'sorting' => 'sorting'
    ];

    /**
     * PropertyHelpers are called after initial build via mapping
     *
     *      "newProperty" => [
     *          [
     *              "className" => class1::class,
     *              "configuration => ["red"]
     *          ],
     *          [
     *              "className" => class2::class
     *          ]
     *      ]
     *
     * @var array
     */
    protected $propertyHelpers = [
        'sorting' => [
            [
                'className' => CreateSortingNumberFromPropertyPropertyHelper::class,
                'configuration' => [
                    'property' => 'title'
                ]
            ]
        ]
    ];
}

3. MigratorS

File EXT:migration_extend/Classes/Migration/Migrator/ContentMigrator.php (migrates news plugins):

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\Migrator;

use In2code\Migration\Migration\Migrator\AbstractMigrator;
use In2code\Migration\Migration\Migrator\MigratorInterface;
use In2code\Migration\Migration\PropertyHelpers\FlexFormGeneratorPropertyHelper;

/**
 * Class ContentMigrator
 */
class ContentMigrator extends AbstractMigrator implements MigratorInterface
{
    /**
     * @var string
     */
    protected $tableName = 'tt_content';

    /**
     * @var array
     */
    protected $propertyHelpers = [
        'pi_flexform' => [
            [
                // Build FlexForm for News plugin
                'className' => FlexFormGeneratorPropertyHelper::class,
                'configuration' => [
                    'condition' => [
                        'CType' => 'list',
                        'list_type' => '9' // Tt_news plugin
                    ],
                    'flexFormTemplate' => 'EXT:migration_extend/Resources/Private/FlexForms/News.xml',
                    'flexFormField' => 'pi_flexform',
                    'overwriteValues' => [
                        'list_type' => 'news_pi1'
                    ],
                    'additionalMapping' => [
                        [
                            // create new variable {additionalMapping.switchableControllerActions}
                            'variableName' => 'switchableControllerActions',
                            'keyField' => 'flexForm:what_to_display', // "flexForm:path/path" or: "row:uid"
                            'mapping' => [
                                'LIST' => 'News->list;News->detail',
                                'LIST2' => 'News->list;News->detail',
                                'LIST3' => 'News->list;News->detail',
                                'HEADER_LIST' => 'News->list;News->detail',
                                'LATEST' => 'News->list;News->detail',
                                'SINGLE' => 'News->detail',
                                'SINGLE2' => 'News->detail',
                                'AMENU' => 'News->list;News->detail',
                                'SEARCH' => 'News->list;News->detail',
                                'CATMENU' => 'News->list;News->detail',
                                'VERSION_PREVIEW' => 'News->list;News->detail',
                                'EVENT_FUTURE' => 'News->list;News->detail',
                                'EVENT_PAST' => 'News->list;News->detail',
                                'LATEST_EVENT_PAST' => 'News->list;News->detail',
                                'LATEST_EVENT_FUTURE' => 'News->list;News->detail',
                                'EVENT_CURRENT' => 'News->list;News->detail',
                                'LATEST_EVENT_CURRENT' => 'News->list;News->detail',
                                'EVENT_REGISTERABLE' => 'News->list;News->detail',
                                'LATEST_EVENT_REGISTERABLE' => 'News->list;News->detail'
                            ]
                        ],
                        [
                            // create new variable {additionalMapping.categorySetting}
                            'variableName' => 'categorySetting',
                            'keyField' => 'flexForm:categoryMode', // "flexForm:path/path" or: "row:uid"
                            'mapping' => [
                                '0' => '', // show all
                                '1' => 'or', // show from categories (OR)
                                '2' => 'and', // show from categories (AND)
                                '-1' => 'notand', // don't show from categories (AND)
                                '-2' => 'notor', // don't show from categories (OR)
                            ]
                        ],
                        [
                            // create new variable {additionalMapping.archiveSetting}
                            'variableName' => 'archiveSetting',
                            'keyField' => 'flexForm:archive', // "flexForm:path/path" or: "row:uid"
                            'mapping' => [
                                '0' => '', // don't care
                                '1' => 'archived', // archived only
                                '-1' => 'active', // not archived only
                            ]
                        ]
                    ]
                ]
            ]
        ],
    ];
}

File EXT:migration_extend/Classes/Migration/Migrator/NewsMigrator.php (Extended migration of news records with relations):

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\Migrator;

use In2code\Migration\Migration\Migrator\AbstractMigrator;
use In2code\Migration\Migration\Migrator\MigratorInterface;
use In2code\Migration\Migration\PropertyHelpers\SlugPropertyHelper;
use In2code\MigrationExtend\Migration\PropertyHelpers\CreateNewsCategoryRelationPropertyHelper;
use In2code\MigrationExtend\Migration\PropertyHelpers\CreateNewsFileRelationsPropertyHelper;
use In2code\MigrationExtend\Migration\PropertyHelpers\CreateNewsImageRelationAndMoveImagePropertyHelper;
use In2code\MigrationExtend\Migration\PropertyHelpers\CreateNewsRelatedRelationsPropertyHelper;

/**
 * Class NewsMigrator
 * To update previous imported news records with relations
 */
class NewsMigrator extends AbstractMigrator implements MigratorInterface
{
    /**
     * @var string
     */
    protected $tableName = 'tx_news_domain_model_news';

    /**
     * @var bool
     */
    protected $enforce = true;

    /**
     * Filter selection of old records like "and pid > 0" (to prevent elements in a workflow e.g.)
     *
     * @var string
     */
    protected $additionalWhere = 'and _migrated=1 and _migrated_table="tt_news" and _migrated_twice=0';

    /**
     * @var array
     */
    protected $values = [
        '_migrated_twice' => 1 // Don't migrate a second time (for other branches that should also be migrated)
    ];

    /**
     * @var array
     */
    protected $sql = [
        'end' => [
            'update sys_file_reference r left join tx_news_domain_model_news n on r.uid_foreign = n.uid
            set r.pid = n.pid where r.tablenames LIKE "tx_news_domain_model_news" and n.deleted=0'
        ]
    ];

    /**
     * @var array
     */
    protected $propertyHelpers = [
        'categories' => [
            [
                'className' => CreateNewsCategoryRelationPropertyHelper::class
            ]
        ],
        'fal_media' => [
            [
                'className' => CreateNewsImageRelationAndMoveImagePropertyHelper::class
            ]
        ],
        'fal_related_files' => [
            [
                'className' => CreateNewsFileRelationsPropertyHelper::class
            ]
        ],
        'related' => [
            [
                'className' => CreateNewsRelatedRelationsPropertyHelper::class
            ]
        ],
        'path_segment' => [
            [
                'className' => SlugPropertyHelper::class,
                'configuration' => [
                    'conditions' => [
                        'deleted' => [
                            '0'
                        ]
                    ]
                ]
            ]
        ]
    ];
}

File EXT:migration_extend/Classes/Migration/Migrator/CategoriesMigrator.php (Extended migration of categories):

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\Migrator;

use In2code\Migration\Migration\Migrator\AbstractMigrator;
use In2code\Migration\Migration\Migrator\MigratorInterface;
use In2code\MigrationExtend\Migration\PropertyHelpers\GetParentCategoryPropertyHelper;

/**
 * Class CategoriesMigrator
 */
class CategoriesMigrator extends AbstractMigrator implements MigratorInterface
{
    /**
     * @var string
     */
    protected $tableName = 'sys_category';

    /**
     * @var bool
     */
    protected $enforce = true;

    /**
     * Filter selection of old records like "and pid > 0" (to prevent elements in a workflow e.g.)
     *
     * @var string
     */
    protected $additionalWhere = 'and _migrated=1 and _migrated_table="tt_news_cat" and _migrated_twice=0';

    /**
     * @var array
     */
    protected $values = [
        '_migrated_twice' => 1 // Don't migrate a second time (for other branches that should also be migrated)
    ];

    /**
     * @var array
     */
    protected $propertyHelpers = [
        'parent' => [
            [
                'className' => GetParentCategoryPropertyHelper::class
            ]
        ]
    ];
}

4. PropertyHelpers

File EXT:migration_extend/Classes/Migration/PropertyHelpers/CreateSortingNumberFromPropertyPropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;

/**
 * Class CreateSortingNumberFromPropertyPropertyHelper
 */
class CreateSortingNumberFromPropertyPropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{

    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $sortingArray = $this->getAllOldCategoriesSortedByProperty('sorting');
        $sorting = 10000;
        if (array_key_exists($this->getPropertyFromRecord('uid'), $sortingArray)) {
            $sorting = $sortingArray[$this->getPropertyFromRecordOld('uid')];
        } else {
            $this->log->addError('Category not sortable: ' . $this->getPropertyFromRecordOld('title'));
        }
        $this->setProperty($sorting);
    }

    /**
     * @param string $property
     * @return array
     * @throws DBALException
     */
    protected function getAllOldCategoriesSortedByProperty(string $property): array
    {
        $connection = DatabaseUtility::getConnectionForTable('tt_news_cat');
        $rows = (array)$connection->executeQuery(
            'select uid from tt_news_cat where deleted=0 order by "' . $property . '"'
        )->fetchAll();
        $categories = [];
        $sorting = 100;
        foreach ($rows as $row) {
            $categories[$sorting] = $row['uid'];
            $sorting += 100;
        }
        return array_flip($categories);
    }
}

File EXT:migration_extend/Classes/Migration/PropertyHelpers/GetParentCategoryPropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;

/**
 * Class GetParentCategoryPropertyHelper
 */
class GetParentCategoryPropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{
    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $queryBuilder = DatabaseUtility::getConnectionForTable($this->table);
        $sql = 'select uid from sys_category where _migrated_uid=' . (int)$this->getProperty();
        $value = (string)$queryBuilder->executeQuery($sql)->fetchColumn(0);
        if ($value > 0) {
            $this->log->addMessage('Replace ' . $this->getProperty() . ' with ' . $value . ' in ' . __CLASS__);
            $this->setProperty($value);
        }
    }

    /**
     * @return bool
     */
    public function shouldMigrate(): bool
    {
        return $this->getProperty() > 0;
    }
}

File EXT:migration_extend/Classes/Migration/PropertyHelpers/CreateNewsCategoryRelationPropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\Helper\DatabaseHelper;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;
use In2code\Migration\Utility\ObjectUtility;

/**
 * Class CreateNewsCategoryRelationPropertyHelper
 */
class CreateNewsCategoryRelationPropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{

    /**
     * @var string
     */
    protected $newTableName = 'sys_category_record_mm';

    /**
     * @var string
     */
    protected $oldTableName = 'tt_news_cat_mm';

    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $databaseHelper = ObjectUtility::getObjectManager()->get(DatabaseHelper::class);
        $newsUid = (int)$this->getPropertyFromRecord('uid');
        $newsUidOld = (int)$this->getPropertyFromRecord('_migrated_uid');
        $rows = $this->getOldProperties($newsUidOld);
        foreach ($rows as $row) {
            if ((int)$row['uid_foreign'] > 0) {
                $newCategoryUid = $this->getNewCategoryIdentifier((int)$row['uid_foreign']);
                if ($newCategoryUid > 0) {
                    $newRow = [
                        'uid_foreign' => $newsUid,
                        'uid_local' => $newCategoryUid,
                        'sorting' => $row['sorting'],
                        'tablenames' => 'tx_news_domain_model_news',
                        'fieldname' => $this->propertyName
                    ];
                    $databaseHelper->createRecord($this->newTableName, $newRow);
                    $this->log->addMessage('New relation to category with uid ' . $row['uid_foreign'] . ' created');
                }
            }
        }
    }

    /**
     * @param int $newsUidOld
     * @return array
     * @throws DBALException
     */
    protected function getOldProperties(int $newsUidOld): array
    {
        $connection = DatabaseUtility::getConnectionForTable($this->oldTableName);
        $rows = (array)$connection->executeQuery(
            'select * from ' . $this->oldTableName . ' where uid_local=' . (int)$newsUidOld
        )->fetchAll();
        return $rows;
    }

    /**
     * @param int $oldIdentifier
     * @return int
     */
    protected function getNewCategoryIdentifier(int $oldIdentifier): int
    {
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('sys_category');
        return (int)$queryBuilder
            ->select('uid')
            ->from('sys_category')
            ->where('_migrated_uid=' . $oldIdentifier . ' and _migrated_table="tt_news_cat"')
            ->setMaxResults(1)
            ->execute()
            ->fetchColumn(0);
    }
}

File EXT:migration_extend/Classes/Migration/PropertyHelpers/CreateNewsImageRelationAndMoveImagePropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\Helper\FileHelper;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;
use In2code\Migration\Utility\ObjectUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Class CreateNewsImageRelationAndMoveImagePropertyHelper
 */
class CreateNewsImageRelationAndMoveImagePropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{
    /**
     * @var string
     */
    protected $targetFolder = 'files/_migrated/news_images/';

    /**
     * @var string
     */
    protected $oldFolder = 'uploads/pics/';

    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $fileHelper = ObjectUtility::getObjectManager()->get(FileHelper::class);
        $imageNames = $this->getImageNames();
        foreach ($imageNames as $key => $imageName) {
            $fileHelper->copyFileAndCreateReference(
                $this->oldFolder . $imageName,
                $this->targetFolder,
                $this->table,
                $this->propertyName,
                $this->getPropertyFromRecord('uid'),
                $this->getAdditionalProperties($key)
            );
            $this->log->addMessage('Image copied and created relation to it (' . $imageName . ')');
        }
    }

    /**
     * @param int $key
     * @return array
     */
    protected function getAdditionalProperties(int $key): array
    {
        $titleTexts = $this->getTitleTexts();
        $altTexts = $this->getAltTexts();
        $imageCaptions = $this->getImageCaptions();
        $links = $this->getImageLinks();

        $additionalProperties = ['showinpreview' => 1];
        if (array_key_exists($key, $titleTexts)) {
            $additionalProperties['title'] = $titleTexts[$key];
        }
        if (array_key_exists($key, $altTexts)) {
            $additionalProperties['alternative'] = $altTexts[$key];
        }
        if (array_key_exists($key, $imageCaptions)) {
            $additionalProperties['description'] = $imageCaptions[$key];
        }
        if (array_key_exists($key, $links)) {
            $additionalProperties['link'] = $links[$key];
        }
        return $additionalProperties;
    }

    /**
     * @return array
     */
    protected function getImageNames(): array
    {
        return GeneralUtility::trimExplode(',', $this->getPropertyFromRecordOld('image'), true);
    }

    /**
     * @return array
     */
    protected function getTitleTexts(): array
    {
        return GeneralUtility::trimExplode(PHP_EOL, $this->getPropertyFromRecordOld('imagetitletext'), true);
    }

    /**
     * @return array
     */
    protected function getAltTexts(): array
    {
        return GeneralUtility::trimExplode(PHP_EOL, $this->getPropertyFromRecordOld('imagealttext'), true);
    }

    /**
     * @return array
     */
    protected function getImageCaptions(): array
    {
        return GeneralUtility::trimExplode(PHP_EOL, $this->getPropertyFromRecordOld('imagecaption'), true);
    }

    /**
     * @return array
     */
    protected function getImageLinks(): array
    {
        return GeneralUtility::trimExplode(PHP_EOL, $this->getPropertyFromRecordOld('links'), true);
    }

    /**
     * Overrule original function and get values from original tt_news record
     *
     * @param string $propertyName
     * @return int|string
     */
    protected function getPropertyFromRecordOld(string $propertyName)
    {
        $propertiesOld = $this->getPropertiesFromOldRecord();
        if (array_key_exists($propertyName, $propertiesOld)) {
            return $propertiesOld[$propertyName];
        } else {
            throw new \LogicException('Property does not exist in ' . __CLASS__, 1569587312);
        }
    }

    /**
     * @return array
     */
    protected function getPropertiesFromOldRecord(): array
    {
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('tt_news');
        return (array)$queryBuilder->select('*')
            ->from('tt_news')
            ->where('uid=' . (int)$this->getPropertyFromRecord('_migrated_uid'))
            ->execute()
            ->fetch();
    }
}

File EXT:migration_extend/Classes/Migration/PropertyHelpers/CreateNewsFileRelationsPropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\Helper\FileHelper;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;
use In2code\Migration\Utility\ObjectUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Class CreateNewsFileRelationsPropertyHelper
 */
class CreateNewsFileRelationsPropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{
    /**
     * @var string
     */
    protected $targetFolder = 'files/_migrated/news_files/';

    /**
     * @var string
     */
    protected $oldFolder = 'uploads/media/';

    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $fileHelper = ObjectUtility::getObjectManager()->get(FileHelper::class);
        $fileNames = GeneralUtility::trimExplode(',', $this->getPropertyFromRecordOld('news_files'), true);
        foreach ($fileNames as $fileName) {
            if (is_file(GeneralUtility::getFileAbsFileName($this->oldFolder . $fileName)) === true) {
                $fileHelper->copyFileAndCreateReference(
                    $this->oldFolder . $fileName,
                    $this->targetFolder,
                    'tx_news_domain_model_news',
                    $this->propertyName,
                    $this->getPropertyFromRecord('uid')
                );
                $this->log->addMessage('Related file moved and created relation to it (' . $fileName . ')');
            }
        }
    }

    /**
     * Overrule original function and get values from original tt_news record
     *
     * @param string $propertyName
     * @return int|string
     */
    protected function getPropertyFromRecordOld(string $propertyName)
    {
        $propertiesOld = $this->getPropertiesFromOldRecord();
        if (array_key_exists($propertyName, $propertiesOld)) {
            return $propertiesOld[$propertyName];
        } else {
            throw new \LogicException('Property does not exist in ' . __CLASS__, 1569920259);
        }
    }

    /**
     * @return array
     */
    protected function getPropertiesFromOldRecord(): array
    {
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('tt_news');
        return (array)$queryBuilder->select('*')
            ->from('tt_news')
            ->where('uid=' . (int)$this->getPropertyFromRecord('_migrated_uid'))
            ->execute()
            ->fetch();
    }
}

File EXT:migration_extend/Classes/Migration/PropertyHelpers/CreateNewsRelatedRelationsPropertyHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\Migration\PropertyHelpers;

use Doctrine\DBAL\DBALException;
use In2code\Migration\Migration\Helper\DatabaseHelper;
use In2code\Migration\Migration\PropertyHelpers\AbstractPropertyHelper;
use In2code\Migration\Migration\PropertyHelpers\PropertyHelperInterface;
use In2code\Migration\Utility\DatabaseUtility;
use In2code\Migration\Utility\ObjectUtility;

/**
 * Class CreateNewsRelatedRelationsPropertyHelper
 */
class CreateNewsRelatedRelationsPropertyHelper extends AbstractPropertyHelper implements PropertyHelperInterface
{

    /**
     * @var string
     */
    protected $mmTableName = 'tx_news_domain_model_news_related_mm';

    /**
     * @return void
     * @throws DBALException
     */
    public function manipulate(): void
    {
        $identifiersOld = $this->getRelatedTtNews();
        if ($identifiersOld !== []) {
            foreach ($identifiersOld as $key => $identifierOld) {
                $identifier = $this->changeIdentifierFromOldToNew($identifierOld);
                $properties = [
                    'uid_foreign' => (int)$this->getPropertyFromRecord('uid'),
                    'uid_local' => $identifier,
                    'sorting' => $key
                ];
                $databaseHelper = ObjectUtility::getObjectManager()->get(DatabaseHelper::class);
                $databaseHelper->createRecord($this->mmTableName, $properties);
                $this->log->addMessage(
                    'new news relation added to news ' . $this->getPropertyFromRecord('uid') . '<=>' . $identifier
                );
            }
        }
    }

    /**
     * @return int[]
     */
    protected function getRelatedTtNews(): array
    {
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('tt_news_related_mm');
        $rows = (array)$queryBuilder->select('*')
            ->from('tt_news_related_mm')
            ->where('uid_local=' . (int)$this->getPropertyFromRecord('_migrated_uid'))
            ->execute()
            ->fetchAll();
        $identifiers = [];
        foreach ($rows as $row) {
            if ($row['uid_foreign'] > 0) {
                $identifiers[] = (int)$row['uid_foreign'];
            }
        }
        return $identifiers;
    }

    /**
     * @param int $oldIdentifier
     * @return int
     */
    protected function changeIdentifierFromOldToNew(int $oldIdentifier): int
    {
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('tx_news_domain_model_news');
        return (int)$queryBuilder->select('uid')
            ->from('tx_news_domain_model_news')
            ->where('_migrated_uid=' . (int)$oldIdentifier)
            ->execute()
            ->fetchColumn(0);
    }
}

5. FlexForm Templates

File EXT:migration_extend/Resources/Private/FlexForms/News.xml:

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<T3FlexForms>
    <data>
        <sheet index="sDEF">
            <language index="lDEF">
                <field index="settings.orderDirection">
                    <value index="vDEF">{flexForm.ascDesc}</value>
                </field>
                <field index="settings.categories">
                    <value index="vDEF">{migrationextend:convertNewsCategoryListToNewCategoryList(list:flexForm.categorySelection)}</value>
                </field>
                <field index="settings.categoryConjunction">
                    <value index="vDEF">{additionalMapping.categorySetting}</value>
                </field>
                <field index="settings.startingpoint">
                    <value index="vDEF">{flexForm.pages}</value>
                </field>
                <field index="switchableControllerActions">
                    <value index="vDEF">{additionalMapping.switchableControllerActions}</value>
                </field>
                <field index="settings.includeSubCategories">
                    <value index="vDEF">{flexForm.useSubCategories}</value>
                </field>
                <field index="settings.archiveRestriction">
                    <value index="vDEF">{additionalMapping.archiveSetting}</value>
                </field>
            </language>
        </sheet>
        <sheet index="additional">
            <language index="lDEF">
                <field index="settings.detailPid">
                    <value index="vDEF">{flexForm.PIDitemDisplay}</value>
                </field>
                <field index="settings.listPid">
                    <value index="vDEF">{flexForm.backPid}</value>
                </field>
                <field index="settings.limit">
                    <value index="vDEF">{flexForm.listLimit}</value>
                </field>
                <field index="settings.backPid">
                    <value index="vDEF">{flexForm.backPid}</value>
                </field>
            </language>
        </sheet>
        <sheet index="template">
            <language index="lDEF">
                <field index="settings.templateLayout">
                    <value index="vDEF"></value>
                </field>
            </language>
        </sheet>
    </data>
</T3FlexForms>

6. ViewHelpers

File EXT:migration_extend/Classes/ViewHelpers/ConvertNewsCategoryListToNewCategoryListViewHelper.php:

<?php
declare(strict_types=1);
namespace In2code\MigrationExtend\ViewHelpers;

use In2code\Migration\Utility\DatabaseUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;

/**
 * Class ConvertNewsCategoryListToNewCategoryListViewHelper
 */
class ConvertNewsCategoryListToNewCategoryListViewHelper extends AbstractViewHelper
{
    /**
     * @return void
     */
    public function initializeArguments()
    {
        $this->registerArgument('list', 'string', 'list with tt_news_cat uids', true);
    }

    /**
     * @return string
     */
    public function render(): string
    {
        $newList = [];
        $categoriesOld = GeneralUtility::intExplode(',', $this->arguments['list']);
        $queryBuilder = DatabaseUtility::getQueryBuilderForTable('sys_category');
        foreach ($categoriesOld as $categoryOld) {
            $newList[] = (int)$queryBuilder
                ->select('uid')
                ->from('sys_category')
                ->where('_migrated_uid=' . $categoryOld . ' and _migrated_table="tt_news_cat"')
                ->setMaxResults(1)
                ->orderBy('uid', 'desc')
                ->execute()
                ->fetchColumn(0);
        }
        return implode(',', $newList);
    }
}

Note: We copied the many files from an old project and I hope that we haven't forgotten anything important. It may be that the namespace, etc.. has changed slightly at one point or another. Not all functions are listed here either: There is always a DatabaseUtility class, which, however, only returns a QueryBuilder or Connection class.