Add process plugin to merge sources with existing destination values

Signed-off-by: Stefan Borchert <[email protected]>

src/Plugin/migrate/process/MergeMigrationLookup.php

@@ -0,0 +1,132 @@
+<?php
+
+namespace Drupal\up_migrate\Plugin\migrate\process;
+
+use Drupal\migrate\MigrateExecutableInterface;
+use Drupal\migrate\Plugin\migrate\process\MigrationLookup;
+use Drupal\migrate\Plugin\MigrateIdMapInterface;
+use Drupal\migrate\Plugin\MigrationInterface;
+use Drupal\migrate\Row;
+
+/**
+ * Lookup a property value based on a migration and merge with existing values.
+ *
+ * Example:
+ * <code>
+ * process:
+ * uid:
+ * plugin: up_merge_migration_lookup
+ * migration: up_user_account
+ * source: uid
+ * source_ids:
+ * up_user_account:
+ * - username
+ * - email
+ * </code>
+ *
+ * @MigrateProcessPlugin(
+ * id = "up_merge_migration_lookup"
+ * )
+ */
+class MergeMigrationLookup extends MigrationLookup {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
+ $migration_ids = $this->configuration['migration'];
+ if (!is_array($migration_ids)) {
+ $migration_ids = [$migration_ids];
+ }
+ if (!is_array($value)) {
+ $value = [$value];
+ }
+ $this->skipOnEmpty($value);
+ $self = FALSE;
+ $destination_ids = NULL;
+ $source_id_values = [];
+ /** @var MigrationInterface[] $migrations */
+ $migrations = $this->migrationPluginManager->createInstances($migration_ids);
+ foreach ($migrations as $migration_id => $migration) {
+ if ($migration_id == $this->migration->id()) {
+ $self = TRUE;
+ }
+ if (isset($this->configuration['source_ids'][$migration_id])) {
+ $configuration = ['source' => $this->configuration['source_ids'][$migration_id]];
+ $source_id_values[$migration_id] = $this->processPluginManager
+ ->createInstance('get', $configuration, $this->migration)
+ ->transform(NULL, $migrate_executable, $row, $destination_property);
+ }
+ else {
+ $source_id_values[$migration_id] = $value;
+ }
+ // Break out of the loop as soon as a destination ID is found.
+ if ($destination_ids = $migration->getIdMap()->lookupDestinationId($source_id_values[$migration_id])) {
+ $value = reset($destination_ids);
+ // Set destination property to first destination id.
+ $row->setDestinationProperty($destination_property, $value);
+ // Skip further processing of this row, while the mapping is saved.
+ throw new MigrateSkipRowException();
+ }
+ }
+
+ if (!empty($this->configuration['no_stub'])) {
+ return NULL;
+ }
+
+ if (($self || isset($this->configuration['stub_id']) || count($migrations) == 1)) {
+ // If the lookup didn't succeed, figure out which migration will do the
+ // stubbing.
+ if ($self) {
+ $migration = $this->migration;
+ }
+ elseif (isset($this->configuration['stub_id'])) {
+ $migration = $migrations[$this->configuration['stub_id']];
+ }
+ else {
+ $migration = reset($migrations);
+ }
+ $destination_plugin = $migration->getDestinationPlugin(TRUE);
+ // Only keep the process necessary to produce the destination ID.
+ $process = $migration->getProcess();
+ if (!empty($process[$destination_property])) {
+ // Remove process information for the previously set destination since
+ // we now don't want to use the migration to lookup the value again.
+ unset($process[$destination_property]);
+ }
+
+ // We already have the source ID values but need to key them for the Row
+ // constructor.
+ $source_ids = $migration->getSourcePlugin()->getIds();
+ $values = [];
+ foreach (array_keys($source_ids) as $index => $source_id) {
+ $values[$source_id] = $source_id_values[$migration->id()][$index];
+ }
+
+ $stub_row = new Row($values + $migration->getSourceConfiguration(), $source_ids, TRUE);
+
+ // Do a normal migration with the stub row.
+ $migrate_executable->processRow($stub_row, $process);
+ $destination_ids = [];
+ try {
+ $destination_ids = $destination_plugin->import($stub_row);
+ }
+ catch (\Exception $e) {
+ $migration->getIdMap()->saveMessage($stub_row->getSourceIdValues(), $e->getMessage());
+ }
+
+ if ($destination_ids) {
+ $migration->getIdMap()->saveIdMapping($stub_row, $destination_ids, MigrateIdMapInterface::STATUS_NEEDS_UPDATE);
+ }
+ }
+ if ($destination_ids) {
+ if (count($destination_ids) == 1) {
+ return reset($destination_ids);
+ }
+ else {
+ return $destination_ids;
+ }
+ }
+ }
+
+}