[Backport] Fixing timeline exportation

taiga/export_import/serializers/fields.py

@@ -25,6 +25,7 @@ from django.core.files.base import ContentFile
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.exceptions import ValidationError
 from django.utils.translation import ugettext as _
+from django.contrib.contenttypes.models import ContentType
 
 from taiga.base.api import serializers
 from taiga.base.fields import JsonField
@@ -68,6 +69,21 @@ class FileField(serializers.WritableField):
         return ContentFile(decoded_data, name=data['name'])
 
 
+class ContentTypeField(serializers.RelatedField):
+    read_only = False
+
+    def to_native(self, obj):
+        if obj:
+            return [obj.app_label, obj.model]
+        return None
+
+    def from_native(self, data):
+        try:
+            return ContentType.objects.get_by_natural_key(*data)
+        except Exception:
+            return None
+
+
 class RelatedNoneSafeField(serializers.RelatedField):
     def field_from_native(self, data, files, field_name, into):
         if self.read_only:

taiga/export_import/serializers/serializers.py

@@ -40,7 +40,7 @@ from taiga.projects.votes import services as votes_service
 from .fields import (FileField, RelatedNoneSafeField, UserRelatedField,
                      UserPkField, CommentField, ProjectRelatedField,
                      HistoryUserField, HistoryValuesField, HistoryDiffField,
-                     TimelineDataField)
+                     TimelineDataField, ContentTypeField)
 from .mixins import (HistoryExportSerializerMixin,
                      AttachmentExportSerializerMixin,
                      CustomAttributesValuesExportSerializerMixin,
@@ -317,9 +317,10 @@ class WikiLinkExportSerializer(serializers.ModelSerializer):
 
 class TimelineExportSerializer(serializers.ModelSerializer):
     data = TimelineDataField()
+    data_content_type = ContentTypeField()
     class Meta:
         model = timeline_models.Timeline
-        exclude = ('id', 'project', 'namespace', 'object_id')
+        exclude = ('id', 'project', 'namespace', 'object_id', 'content_type')
 
 
 class ProjectExportSerializer(WatcheableObjectModelSerializerMixin):

taiga/export_import/services/store.py

@@ -577,6 +577,7 @@ def _store_timeline_entry(project, timeline):
         serialized.object.project = project
         serialized.object.namespace = build_project_namespace(project)
         serialized.object.object_id = project.id
+        serialized.object.content_type = ContentType.objects.get_for_model(project.__class__)
         serialized.object._importing = True
         serialized.save()
         return serialized
@@ -725,7 +726,7 @@ def store_project_from_dict(data, owner=None):
     except err.TaigaImportError:
         # reraise known inport errors
         raise
-    except:
+    except Exception:
         # reise unknown errors as import error
         raise err.TaigaImportError(_("unexpected error importing project"), project)