feat: add version id to entity

Refs: #13

cubicweb_s3storage/storages.py

@@ -33,6 +33,7 @@
 
 class S3Storage(Storage):
     is_source_callback = True
+    KEY_SEPARATOR = '#'
 
     def __init__(self, bucket, suffix='.tmp'):
         self.s3cnx = self._s3_client()
@@ -87,10 +88,6 @@
         else:
             oldkey = self.get_s3_key(entity, attr)
             key = self.new_s3_key(entity, attr)
-            # save S3 key
-            entity.cw_edited.edited_attribute(
-                attr, Binary(key.encode('utf-8')))
-
             # copy Binary value, workaround for boto3 bug
             # https://github.com/boto/s3transfer/issues/80
             # .read() is required since Binary can't wrap itself
@@ -108,6 +105,9 @@
                                                       Key=upload_key,
                                                       **extra_args)
             buffer.close()
+            version_id = put_object_result.get('VersionId', None)
+            # save S3 key
+            entity = self.save_s3_key(entity, attr, upload_key, version_id)
 
             # when key is suffixed, move to final key in post commit event
             # remove temporary key on rollback
@@ -160,6 +160,24 @@
             source.doexec(cnx, sql, attrs)
         entity.cw_edited = None
 
+    def save_s3_key(self, entity, attr, key, version_id=None):
+        """
+        Save the s3 key into the entity bytes attribute
+        """
+        id_string = key
+        if entity._cw.repo.config['s3-activate-object-versioning'] and \
+           version_id is not None:
+            id_string = self.format_version_id_suffix(key, version_id)
+        entity.cw_edited.edited_attribute(attr,
+                                          Binary(id_string.encode('utf-8')))
+        return entity
+
+    def format_version_id_suffix(self, key, version_id):
+        """
+        Format the string that will store key and version id
+        """
+        return f"{key}{self.KEY_SEPARATOR}{version_id}"
+
     def get_s3_key(self, entity, attr):
         """
         Return the S3 key of the S3 object storing the content of attribute