Issue #2263453 by chx, benjy: Split migration_dependencies into two keys.

core/modules/migrate/lib/Drupal/migrate/MigrationStorage.php

@@ -20,34 +20,28 @@ class MigrationStorage extends ConfigEntityStorage implements MigrateBuildDepend
    */
   public function buildDependencyMigration(array $migrations, array $dynamic_ids) {
     // Migration dependencies defined in the migration storage can be
-    // soft dependencies: if a soft dependency does not run, the current
-    // migration is still OK to go. This is indicated by adding ": false"
-    // (without quotes) after the name of the dependency. Hard dependencies
-    // (default) are called requirements. Both hard and soft dependencies (if
-    // run at all) must run before the current one.
+    // optional or required. If an optional dependency does not run, the current
+    // migration is still OK to go. Both optional and required dependencies
+    // (if run at all) must run before the current migration.
     $dependency_graph = array();
     $requirement_graph = array();
     $different = FALSE;
     foreach ($migrations as $migration) {
-      /** @var \Drupal\migrate\Entity\MigrationInterface $migration */
+      /** @var \Drupal\migrate\Entity\Migration $migration */
       $id = $migration->id();
       $requirements[$id] = array();
       $dependency_graph[$id]['edges'] = array();
-      if (isset($migration->migration_dependencies) && is_array($migration->migration_dependencies)) {
-        foreach ($migration->migration_dependencies as $dependency) {
-          if (is_string($dependency) && !isset($dynamic_ids[$dependency])) {
+      if (isset($migration->migration_dependencies['required'])) {
+        foreach ($migration->migration_dependencies['required'] as $dependency) {
+          if (!isset($dynamic_ids[$dependency])) {
             $this->addDependency($requirement_graph, $id, $dependency, $dynamic_ids);
           }
-          if (is_array($dependency)) {
-            list($dependency_string, $required) = each($dependency);
-            $dependency = $dependency_string;
-            if ($required) {
-              $this->addDependency($requirement_graph, $id, $dependency, $dynamic_ids);
-            }
-            else {
-              $different = TRUE;
-            }
-          }
+          $this->addDependency($dependency_graph, $id, $dependency, $dynamic_ids);
+        }
+      }
+      if (isset($migration->migration_dependencies['optional'])) {
+        foreach ($migration->migration_dependencies['optional'] as $dependency) {
+          $different = TRUE;
           $this->addDependency($dependency_graph, $id, $dependency, $dynamic_ids);
         }
       }

core/modules/migrate/lib/Drupal/migrate/Plugin/migrate/destination/EntityFile.php

@@ -14,6 +14,9 @@
 use Drupal\migrate\Row;
 
 /**
+ * Every migration that uses this destination must have an optional
+ * dependency on the d6_file migration to ensure it runs first.
+ *
  * @MigrateDestination(
  *   id = "entity:file"
  * )

core/modules/migrate_drupal/config/install/migrate.migration.d6_aggregator_item.yml

@@ -18,4 +18,5 @@ process:
 destination:
   plugin: entity:aggregator_item
 migration_dependencies:
-  - d6_aggregator_feed
+  required:
+    - d6_aggregator_feed

core/modules/migrate_drupal/config/install/migrate.migration.d6_block.yml

@@ -58,5 +58,7 @@ process:
 destination:
   plugin: entity:block
 migration_dependencies:
-  - d6_custom_block
-  - d6_menu: false
+  required:
+    - d6_custom_block
+  optional:
+    - d6_menu

core/modules/migrate_drupal/config/install/migrate.migration.d6_book.yml

@@ -16,4 +16,5 @@ process:
 destination:
   plugin: book
 migration_dependencies:
-  - d6_node
+  required:
+    - d6_node

core/modules/migrate_drupal/config/install/migrate.migration.d6_cck_field_revision.yml

@@ -10,5 +10,6 @@ process:
 destination:
   plugin: entity_revision:node
 migration_dependencies:
-  - d6_cck_field_values
-  - d6_node_revision
+  required:
+    - d6_cck_field_values
+    - d6_node_revision

core/modules/migrate_drupal/config/install/migrate.migration.d6_cck_field_values.yml

@@ -13,6 +13,7 @@ process:
 destination:
   plugin: entity:node
 migration_dependencies:
-  - d6_node
-  - d6_field_formatter_settings
-  - d6_field_instance_widget_settings
+  required:
+    - d6_node
+    - d6_field_formatter_settings
+    - d6_field_instance_widget_settings

core/modules/migrate_drupal/config/install/migrate.migration.d6_comment.yml

@@ -44,8 +44,9 @@ process:
 destination:
   plugin: entity:comment
 migration_dependencies:
-  - d6_node
-  - d6_user
-  - d6_comment_entity_display
-  - d6_comment_entity_form_display
-  - d6_filter_format
+  required:
+    - d6_node
+    - d6_user
+    - d6_comment_entity_display
+    - d6_comment_entity_form_display
+    - d6_filter_format

core/modules/migrate_drupal/config/install/migrate.migration.d6_comment_entity_display.yml

@@ -20,4 +20,5 @@ process:
 destination:
   plugin: component_entity_display
 migration_dependencies:
-  - d6_comment_field_instance
+  required:
+    - d6_comment_field_instance

core/modules/migrate_drupal/config/install/migrate.migration.d6_comment_entity_form_display.yml

@@ -19,4 +19,5 @@ process:
 destination:
   plugin: component_entity_form_display
 migration_dependencies:
-  - d6_comment_field_instance
+  required:
+    - d6_comment_field_instance

core/modules/migrate_drupal/config/install/migrate.migration.d6_comment_field_instance.yml

@@ -24,5 +24,6 @@ process:
 destination:
   plugin: entity:field_instance_config
 migration_dependencies:
-  - d6_comment_field
-  - d6_node_type
+  required:
+    - d6_comment_field
+    - d6_node_type

core/modules/migrate_drupal/config/install/migrate.migration.d6_custom_block.yml

@@ -16,4 +16,5 @@ process:
 destination:
   plugin: entity:custom_block
 migration_dependencies:
-  - d6_filter_format
+  required:
+    - d6_filter_format

core/modules/migrate_drupal/config/install/migrate.migration.d6_field.yml

@@ -77,7 +77,8 @@ process:
 destination:
   plugin: entity:field_config
 migration_dependencies:
-  # It is not possible to make this a requirement as d6_field_settings has no
-  # source id. However it also has no requirements so it will always run so a
-  # dependency is enough.
-  - d6_field_settings: false
+  optional:
+    # It is not possible to make this required as d6_field_settings has no
+    # source id. However it also has no required dependencies so it will always
+    # run so an optional dependency is enough.
+    - d6_field_settings

core/modules/migrate_drupal/config/install/migrate.migration.d6_field_formatter_settings.yml

@@ -294,5 +294,6 @@ process:
 destination:
   plugin: component_entity_display
 migration_dependencies:
-  - d6_field_instance
-  - d6_view_modes
+  required:
+    - d6_field_instance
+    - d6_view_modes

core/modules/migrate_drupal/config/install/migrate.migration.d6_field_instance.yml

@@ -44,5 +44,6 @@ process:
 destination:
   plugin: entity:field_instance_config
 migration_dependencies:
-  - d6_node_type
-  - d6_field
+  required:
+    - d6_node_type
+    - d6_field

core/modules/migrate_drupal/config/install/migrate.migration.d6_field_instance_widget_settings.yml

@@ -54,4 +54,5 @@ process:
 destination:
   plugin: component_entity_form_display
 migration_dependencies:
-  - d6_field_instance
+  required:
+    - d6_field_instance

core/modules/migrate_drupal/config/install/migrate.migration.d6_file.yml

+# Every migration that saves into {file_managed} must have the d6_file
+# migration as an optional dependency to ensure d6_file runs first.
 id: d6_file
 label: Drupal 6 files
 source:

core/modules/migrate_drupal/config/install/migrate.migration.d6_node.yml

@@ -29,8 +29,10 @@ process:
 destination:
   plugin: entity:node
 migration_dependencies:
-  - d6_node_type
-  - d6_filter_format
-  - d6_field_instance_widget_settings: false
-  - d6_field_formatter_settings: false
-  - d6_node_settings: false
+  required:
+    - d6_node_type
+    - d6_filter_format
+  optional:
+    - d6_field_instance_widget_settings
+    - d6_field_formatter_settings
+    - d6_node_settings

core/modules/migrate_drupal/config/install/migrate.migration.d6_node_revision.yml

@@ -29,4 +29,5 @@ process:
 destination:
   plugin: entity_revision:node
 migration_dependencies:
-  - d6_node
+  required:
+    - d6_node

core/modules/migrate_drupal/config/install/migrate.migration.d6_node_settings.yml

@@ -10,4 +10,5 @@ destination:
   plugin: config
   config_name: node.settings
 migration_dependencies:
-  - d6_node_type
+  required:
+    - d6_node_type