[flat field] fix attempt to load dark and flats from *tomwer_processes.h5. Xas...

[flat field] fix attempt to load dark and flats from *tomwer_processes.h5. Xas failing if the file was here but didn't contained any dark or flat

nabu/resources/dataset_analyzer.py

@@ -287,13 +287,15 @@ class HDF5DatasetAnalyzer(DatasetAnalyzer):
                                                  "tomwer_processes.h5")
         if tomwer_processes_file is None or not (os.path.isfile(tomwer_processes_file)):
                 return False
-        self.logger.info("Loading darks and refs from %s" % tomwer_processes_file)
         new_flats = get_flats_frm_process_file(
             tomwer_processes_file, self.dataset_scanner.entry
         )
         new_darks = get_darks_frm_process_file(
             tomwer_processes_file, self.dataset_scanner.entry
         )
+        if not (len(new_flats) > 0 and len(new_darks) > 0):
+            return False
+        self.logger.info("Loading darks and refs from %s" % tomwer_processes_file)
         self.flats = new_flats
         self.darks = new_darks
         return True

nabu/thirdparty/tomwer_load_flats_darks.py

@@ -89,6 +89,8 @@ def get_darks_frm_process_file(process_file, entry) -> typing.Union[None, dict]:
         for key, value in dark_nodes.items():
             index_to_path[key] = key
 
+        if len(dark_nodes) == 0:
+            return {}
         # take the last processed dark ref
         last_process_index = sorted(dark_nodes.keys())[-1]
         last_process_dark = index_to_path[last_process_index]
@@ -133,6 +135,8 @@ def get_flats_frm_process_file(process_file, entry) -> typing.Union[None, dict]:
     with HDF5File(process_file, 'r', swmr=True) as h5f:
         dkref_nodes = get_process_entries(root_node=h5f[entry],
                                           depth=MAX_DEPTH-1)
+        if len(dkref_nodes) == 0:
+            return {}
         index_to_path = {}
         for key, value in dkref_nodes.items():
             index_to_path[key] = key