Add data migration to the file metadata app

Synchronizes the document type settings model of existing
document types.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

mayan/apps/file_metadata/migrations/0002_documenttypesettings.py

@@ -0,0 +1,53 @@
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+def operation_create_file_metadata_setting_for_existing_document_types(apps, schema_editor):
+    DocumentType = apps.get_model(
+        app_label='documents', model_name='DocumentType'
+    )
+    DocumentTypeSettings = apps.get_model(
+        app_label='file_metadata', model_name='DocumentTypeSettings'
+    )
+
+    for document_type in DocumentType.objects.using(schema_editor.connection.alias).all():
+        try:
+            DocumentTypeSettings.objects.using(
+                schema_editor.connection.alias
+            ).get_or_create(document_type=document_type)
+        except DocumentTypeSettings.DoesNotExist:
+            pass
+
+
+def operation_delete_file_metadata_setting_for_existing_document_types(apps, schema_editor):
+    DocumentType = apps.get_model(
+        app_label='documents', model_name='DocumentType'
+    )
+    DocumentTypeSettings = apps.get_model(
+        app_label='file_metadata', model_name='DocumentTypeSettings'
+    )
+
+    for document_type in DocumentType.objects.using(schema_editor.connection.alias).all():
+        try:
+            DocumentTypeSettings.objects.using(
+                schema_editor.connection.alias
+            ).get(document_type=document_type).delete()
+        except DocumentTypeSettings.DoesNotExist:
+            pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '0047_auto_20180917_0737'),
+        ('file_metadata', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            code=operation_create_file_metadata_setting_for_existing_document_types,
+            reverse_code=operation_delete_file_metadata_setting_for_existing_document_types,
+        )
+    ]