Merge pull request #374 from djarecka/enh/callable_updates

improving callable use in output spec

pydra/engine/specs.py

@@ -542,7 +542,25 @@ def _field_metadata(self, fld, inputs, output_dir):
             else:
                 return Path(value)
         elif "callable" in fld.metadata:
-            return fld.metadata["callable"](fld.name, output_dir)
+            call_args = inspect.getargspec(fld.metadata["callable"])
+            call_args_val = {}
+            for argnm in call_args.args:
+                if argnm == "field":
+                    call_args_val[argnm] = fld
+                elif argnm == "output_dir":
+                    call_args_val[argnm] = output_dir
+                elif argnm == "inputs":
+                    call_args_val[argnm] = inputs
+                else:
+                    try:
+                        call_args_val[argnm] = getattr(inputs, argnm)
+                    except AttributeError:
+                        raise AttributeError(
+                            f"arguments of the callable function from {fld.name} "
+                            f"has to be in inputs or be field or output_dir, "
+                            f"but {argnm} is used"
+                        )
+            return fld.metadata["callable"](**call_args_val)
         else:
             raise Exception("(_field_metadata) is not a current valid metadata key.")
 

pydra/engine/tests/test_shelltask.py

@@ -2545,11 +2545,12 @@ def test_shell_cmd_outputspec_4(plugin, results_function, tmpdir):
     """
         customised output_spec, adding files to the output,
         using a function to collect output, the function is saved in the field metadata
+        and uses output_dir and the glob function
     """
     cmd = ["touch", "newfile_tmp1.txt", "newfile_tmp2.txt"]
 
-    def gather_output(keyname, output_dir):
-        if keyname == "newfile":
+    def gather_output(field, output_dir):
+        if field.name == "newfile":
             return list(Path(output_dir).expanduser().glob("newfile*.txt"))
 
     my_output_spec = SpecInfo(
@@ -2568,6 +2569,55 @@ def gather_output(keyname, output_dir):
     assert all([file.exists for file in res.output.newfile])
 
 
+@pytest.mark.parametrize("results_function", [result_no_submitter, result_submitter])
+def test_shell_cmd_outputspec_4a(plugin, results_function):
+    """
+        customised output_spec, adding files to the output,
+        using a function to collect output, the function is saved in the field metadata
+        and uses output_dir and inputs element
+    """
+    cmd = ["touch", "newfile_tmp1.txt", "newfile_tmp2.txt"]
+
+    def gather_output(executable, output_dir):
+        files = executable[1:]
+        return [Path(output_dir) / file for file in files]
+
+    my_output_spec = SpecInfo(
+        name="Output",
+        fields=[("newfile", attr.ib(type=File, metadata={"callable": gather_output}))],
+        bases=(ShellOutSpec,),
+    )
+    shelly = ShellCommandTask(name="shelly", executable=cmd, output_spec=my_output_spec)
+
+    res = results_function(shelly, plugin)
+    assert res.output.stdout == ""
+    # newfile is a list
+    assert len(res.output.newfile) == 2
+    assert all([file.exists for file in res.output.newfile])
+
+
+def test_shell_cmd_outputspec_4b_error():
+    """
+        customised output_spec, adding files to the output,
+        using a function to collect output, the function is saved in the field metadata
+        with an argument that is not part of the inputs - error is raised
+    """
+    cmd = ["touch", "newfile_tmp1.txt", "newfile_tmp2.txt"]
+
+    def gather_output(executable, output_dir, ble):
+        files = executable[1:]
+        return [Path(output_dir) / file for file in files]
+
+    my_output_spec = SpecInfo(
+        name="Output",
+        fields=[("newfile", attr.ib(type=File, metadata={"callable": gather_output}))],
+        bases=(ShellOutSpec,),
+    )
+    shelly = ShellCommandTask(name="shelly", executable=cmd, output_spec=my_output_spec)
+    with pytest.raises(AttributeError, match="ble"):
+        shelly()
+
+
 @pytest.mark.parametrize("results_function", [result_no_submitter, result_submitter])
 def test_shell_cmd_outputspec_5(plugin, results_function, tmpdir):
     """