fixes Project-MONAI#3942

Signed-off-by: Wenqi Li <[email protected]>

monai/bundle/config_item.py

@@ -164,17 +164,22 @@ class ConfigComponent(ConfigItem, Instantiable):
     Subclass of :py:class:`monai.bundle.ConfigItem`, this class uses a dictionary with string keys to
     represent a component of `class` or `function` and supports instantiation.
 
-    Currently, two special keys (strings surrounded by ``_``) are defined and interpreted beyond the regular literals:
-
-        - class or function identifier of the python module, specified by one of the two keys.
-            - ``"_target_"``: indicates build-in python classes or functions such as "LoadImageDict",
-                or full module name, such as "monai.transforms.LoadImageDict".
+    Currently, three special keys (strings surrounded by ``_``) are defined and interpreted beyond the regular literals:
+
+        - class or function identifier of the python module, specified by ``"_target_"``,
+          indicating a build-in python class or function such as ``"LoadImageDict"``,
+          or a full module name, such as ``"monai.transforms.LoadImageDict"``.
+        - ``"_requires_"``: specifies reference IDs (string starts with ``"@"``) or ``ConfigExpression``
+          of the dependencies for this ``ConfigComponent`` object. These dependencies will be
+          evaluated/instantiated before this object is instantiated.
         - ``"_disabled_"``: a flag to indicate whether to skip the instantiation.
 
     Other fields in the config content are input arguments to the python module.
 
     .. code-block:: python
 
+        from monai.bundle import ComponentLocator, ConfigComponent
+
         locator = ComponentLocator(excludes=["modules_to_exclude"])
         config = {
             "_target_": "LoadImaged",
@@ -195,7 +200,7 @@ class ConfigComponent(ConfigItem, Instantiable):
 
     """
 
-    non_arg_keys = {"_target_", "_disabled_"}
+    non_arg_keys = {"_target_", "_disabled_", "_requires_"}
 
     def __init__(
         self,

monai/bundle/config_parser.py

@@ -26,6 +26,8 @@
 
 __all__ = ["ConfigParser"]
 
+_default_globals = {"monai": "monai", "torch": "torch", "np": "numpy", "numpy": "numpy"}
+
 
 class ConfigParser:
     """
@@ -74,7 +76,7 @@ class ConfigParser:
             so that expressions, for example, ``"$monai.data.list_data_collate"`` can use ``monai`` modules.
             The current supported globals and alias names are
             ``{"monai": "monai", "torch": "torch", "np": "numpy", "numpy": "numpy"}``.
-            These are MONAI's minimal dependencies.
+            These are MONAI's minimal dependencies. Additional packages could be included with `globals={"itk": "itk"}`.
 
     See also:
 
@@ -96,9 +98,11 @@ def __init__(
     ):
         self.config = None
         self.globals: Dict[str, Any] = {}
-        globals = {"monai": "monai", "torch": "torch", "np": "numpy", "numpy": "numpy"} if globals is None else globals
-        if globals is not None:
-            for k, v in globals.items():
+        _globals = _default_globals.copy()
+        if isinstance(_globals, dict) and globals is not None:
+            _globals.update(globals)
+        if _globals is not None:
+            for k, v in _globals.items():
                 self.globals[k] = importlib.import_module(v) if isinstance(v, str) else v
 
         self.locator = ComponentLocator(excludes=excludes)

tests/testing_data/inference.json

@@ -1,5 +1,7 @@
 {
     "device": "$torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')",
+    "set_seed": "$monai.utils.set_determinism(0)",
+    "print_test_name": "$print('json_test')",
     "network_def": {
         "_target_": "UNet",
         "spatial_dims": 3,
@@ -93,6 +95,11 @@
     },
     "evaluator": {
         "_target_": "SupervisedEvaluator",
+        "_requires_": [
+            "@set_seed",
+            "@print_test_name",
+            "$print('test_in_line_json')"
+        ],
         "device": "@device",
         "val_data_loader": "@dataloader",
         "network": "@network",

tests/testing_data/inference.yaml

@@ -1,5 +1,7 @@
 ---
 device: "$torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')"
+set_seed: "$monai.utils.set_determinism(0)"
+print_test_name: "$print('yaml_test')"
 network_def:
   _target_: UNet
   spatial_dims: 3
@@ -66,6 +68,10 @@ postprocessing:
     output_dir: "@_meta_#output_dir"
 evaluator:
   _target_: SupervisedEvaluator
+  _requires_:
+    - "$print('test_in_line_yaml')"
+    - "@set_seed"
+    - "@print_test_name"
   device: "@device"
   val_data_loader: "@dataloader"
   network: "@network"