Merge pull request #922 from mgxd/fix/t2w-only-bidsdatagrabber

ENH: Parse kwargs to allow no T1w

niworkflows/interfaces/bids.py

@@ -265,12 +265,13 @@ class BIDSDataGrabber(SimpleInterface):
     _require_funcs = True
 
     def __init__(self, *args, **kwargs):
-        anat_only = kwargs.pop('anat_only')
+        anat_only = kwargs.pop('anat_only', None)
         anat_derivatives = kwargs.pop('anat_derivatives', None)
+        require_t1w = kwargs.pop('require_t1w', True)
         super().__init__(*args, **kwargs)
         if anat_only is not None:
             self._require_funcs = not anat_only
-        self._require_t1w = anat_derivatives is None
+        self._require_t1w = require_t1w and anat_derivatives is None
 
     def _run_interface(self, runtime):
         bids_dict = self.inputs.subject_data

niworkflows/interfaces/tests/test_bids.py

@@ -793,3 +793,16 @@ def test_fsdir_min_version(tmp_path, min_version):
         assert not patched_subject_dir.exists()
     else:
         assert patched_subject_dir.exists()
+
+
+def test_BIDSDataGrabber():
+    x = bintfs.BIDSDataGrabber(anat_only=True)
+    assert x._require_t1w is True
+    assert x._require_funcs is False
+
+    x = bintfs.BIDSDataGrabber(anat_only=False, require_t1w=False)
+    assert x._require_t1w is False
+    assert x._require_funcs is True
+
+    x = bintfs.BIDSDataGrabber(anat_derivatives='derivatives')
+    assert x._require_t1w is False