[add_dark_flat_nx_file] avoid loading the data to get dimensions

nxtomomill/utils.py

@@ -300,10 +300,19 @@ def add_dark_flat_nx_file(
         n_frames_to_insert = 1
         if isinstance(data, numpy.ndarray) and data.ndim == 3:
             n_frames_to_insert = data.shape[0]
+        elif isinstance(data, DataUrl):
+            with HDF5File(data.file_path(), mode="r") as h5s:
+                if data.data_path() not in h5s:
+                    raise KeyError(
+                        "Path given ({}) is not in {}".format(
+                            data.data_path(), data.file_path
+                        )
+                    )
+                data_node = data[data_path()]
+                if data_node.ndim is 3:
+                    n_frames_to_insert = data_node.shape[0]
         else:
-            raw_data = get_data(data)
-            if raw_data.ndim is 3:
-                n_frames_to_insert = raw_data.shape[0]
+            raise TypeError("{} as input is not managed".format(type(data)))
 
         if logger is not None:
             logger.info(