refactor(mixins): extract custom type transforms into utils

1 files changed, 36 insertions, 1 deletions

diff --git a/gitlab/utils.py b/gitlab/utils.py
index 1979355..a05cb22 100644
--- a/gitlab/utils.py
+++ b/gitlab/utils.py
@@ -19,10 +19,12 @@ import pathlib
 import traceback
 import urllib.parse
 import warnings
-from typing import Any, Callable, Dict, Optional, Type, Union
+from typing import Any, Callable, Dict, Optional, Tuple, Type, Union
 
 import requests
 
+from gitlab import types
+
 
 class _StdoutStream:
     def __call__(self, chunk: Any) -> None:
@@ -47,6 +49,39 @@ def response_content(
     return None
 
 
+def _transform_types(
+    data: Dict[str, Any], custom_types: dict, *, transform_files: Optional[bool] = True
+) -> Tuple[dict, dict]:
+    """Copy the data dict with attributes that have custom types and transform them
+    before being sent to the server.
+
+    If ``transform_files`` is ``True`` (default), also populates the ``files`` dict for
+    FileAttribute types with tuples to prepare fields for requests' MultipartEncoder:
+    https://toolbelt.readthedocs.io/en/latest/user.html#multipart-form-data-encoder
+
+    Returns:
+        A tuple of the transformed data dict and files dict"""
+
+    # Duplicate data to avoid messing with what the user sent us
+    data = data.copy()
+    files = {}
+
+    for attr_name, type_cls in custom_types.items():
+        if attr_name not in data:
+            continue
+
+        type_obj = type_cls(data[attr_name])
+
+        # if the type if FileAttribute we need to pass the data as file
+        if transform_files and isinstance(type_obj, types.FileAttribute):
+            key = type_obj.get_file_name(attr_name)
+            files[attr_name] = (key, data.pop(attr_name))
+        else:
+            data[attr_name] = type_obj.get_for_api()
+
+    return data, files
+
+
 def copy_dict(
     *,
     src: Dict[str, Any],