Generic HasIO classes to specify data output panel types

pyiron_workflow/io.py

@@ -220,7 +220,17 @@ def fetch(self):
             c.fetch()
 
 
-class Outputs(OutputsIO, DataIO):
+OutputDataType = TypeVar("OutputDataType", bound=OutputData)
+
+
+class GenericOutputs(OutputsIO, DataIO, Generic[OutputDataType], ABC):
+    @property
+    @abstractmethod
+    def _channel_class(self) -> type[OutputDataType]:
+        pass
+
+
+class Outputs(GenericOutputs[OutputData]):
     @property
     def _channel_class(self) -> type[OutputData]:
         return OutputData
@@ -294,7 +304,10 @@ def __str__(self):
         return f"{str(self.input)}\n{str(self.output)}"
 
 
-class HasIO(HasStateDisplay, HasLabel, HasRun, ABC):
+OutputsType = TypeVar("OutputsType", bound=GenericOutputs)
+
+
+class HasIO(HasStateDisplay, HasLabel, HasRun, Generic[OutputsType], ABC):
     """
     A mixin for classes that provide data and signal IO.
 
@@ -329,7 +342,7 @@ def data_input_locked(self) -> bool:
 
     @property
     @abstractmethod
-    def outputs(self) -> Outputs:
+    def outputs(self) -> OutputsType:
         pass
 
     @property

pyiron_workflow/mixin/has_interface_mixins.py

@@ -11,7 +11,7 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Generic, TypeVar
 
 if TYPE_CHECKING:
     from pyiron_workflow.channels import Channel
@@ -69,9 +69,7 @@ def full_label(self) -> str:
 
 class HasChannel(ABC):
     """
-    A mix-in class for use with the :class:`Channel` class.
-    A :class:`Channel` is able to (attempt to) connect to any child instance of :class:`HasConnection`
-    by looking at its :attr:`connection` attribute.
+    A mix-in class for use with the :class:`Channel` class and its children.
 
     This is useful for letting channels attempt to connect to non-channel objects
     directly by pointing them to some channel that object holds.
@@ -83,6 +81,16 @@ def channel(self) -> Channel:
         pass
 
 
+ChannelType = TypeVar("ChannelType", bound="Channel")
+
+
+class HasGenericChannel(HasChannel, Generic[ChannelType], ABC):
+    @property
+    @abstractmethod
+    def channel(self) -> ChannelType:
+        pass
+
+
 class HasRun(ABC):
     """
     A mixin to guarantee that the :meth:`run` method exists.

pyiron_workflow/mixin/injection.py

@@ -8,11 +8,10 @@
 
 from __future__ import annotations
 
-from abc import ABC, abstractmethod
 from typing import TYPE_CHECKING, Any
 
 from pyiron_workflow.channels import NOT_DATA, OutputData
-from pyiron_workflow.io import HasIO, Outputs
+from pyiron_workflow.io import GenericOutputs
 from pyiron_workflow.mixin.has_interface_mixins import HasChannel
 
 if TYPE_CHECKING:
@@ -275,14 +274,7 @@ def __round__(self):
         return self._node_injection(Round)
 
 
-class OutputsWithInjection(Outputs):
+class OutputsWithInjection(GenericOutputs[OutputDataWithInjection]):
     @property
-    def _channel_class(self) -> type(OutputDataWithInjection):
+    def _channel_class(self) -> type[OutputDataWithInjection]:
         return OutputDataWithInjection
-
-
-class HasIOWithInjection(HasIO, ABC):
-    @property
-    @abstractmethod
-    def outputs(self) -> OutputsWithInjection:
-        pass

pyiron_workflow/mixin/single_output.py

@@ -7,7 +7,8 @@
 
 from abc import ABC, abstractmethod
 
-from pyiron_workflow.mixin.has_interface_mixins import HasChannel, HasLabel
+from pyiron_workflow.io import HasIO
+from pyiron_workflow.mixin.has_interface_mixins import HasGenericChannel
 from pyiron_workflow.mixin.injection import (
     OutputDataWithInjection,
     OutputsWithInjection,
@@ -18,7 +19,9 @@ class AmbiguousOutputError(ValueError):
     """Raised when searching for exactly one output, but multiple are found."""
 
 
-class ExploitsSingleOutput(HasLabel, HasChannel, ABC):
+class ExploitsSingleOutput(
+    HasIO[OutputsWithInjection], HasGenericChannel[OutputDataWithInjection], ABC
+):
     @property
     @abstractmethod
     def outputs(self) -> OutputsWithInjection:

pyiron_workflow/node.py

@@ -19,7 +19,6 @@
 
 from pyiron_workflow.draw import Node as GraphvizNode
 from pyiron_workflow.logging import logger
-from pyiron_workflow.mixin.injection import HasIOWithInjection
 from pyiron_workflow.mixin.run import ReadinessError, Runnable
 from pyiron_workflow.mixin.semantics import Semantic
 from pyiron_workflow.mixin.single_output import ExploitsSingleOutput
@@ -40,7 +39,6 @@
 
 
 class Node(
-    HasIOWithInjection,
     Semantic["Composite"],
     Runnable,
     ExploitsSingleOutput,
@@ -179,8 +177,9 @@ class Node(
         inputs (pyiron_workflow.io.Inputs): **Abstract.** Children must define
             a property returning an :class:`Inputs` object.
         label (str): A name for the node.
-        outputs (pyiron_workflow.io.Outputs): **Abstract.** Children must define
-            a property returning an :class:`Outputs` object.
+        outputs (pyiron_workflow.mixin.injection.OutputsWithInjection): **Abstract.**
+            Children must define a property returning an :class:`OutputsWithInjection`
+            object.
         parent (pyiron_workflow.composite.Composite | None): The parent object
             owning this, if any.
         ready (bool): Whether the inputs are all ready and the node is neither

pyiron_workflow/nodes/macro.py

@@ -13,8 +13,9 @@
 
 from pyiron_snippets.factory import classfactory
 
-from pyiron_workflow.io import Inputs, Outputs
+from pyiron_workflow.io import Inputs
 from pyiron_workflow.mixin.has_interface_mixins import HasChannel
+from pyiron_workflow.mixin.injection import OutputsWithInjection
 from pyiron_workflow.mixin.preview import ScrapesIO
 from pyiron_workflow.nodes.composite import Composite
 from pyiron_workflow.nodes.multiple_distpatch import dispatch_output_labels
@@ -342,7 +343,7 @@ def inputs(self) -> Inputs:
         return self._inputs
 
     @property
-    def outputs(self) -> Outputs:
+    def outputs(self) -> OutputsWithInjection:
         return self._outputs
 
     def _parse_remotely_executed_self(self, other_self):

pyiron_workflow/workflow.py

@@ -10,7 +10,8 @@
 
 from bidict import bidict
 
-from pyiron_workflow.io import Inputs, Outputs
+from pyiron_workflow.io import Inputs
+from pyiron_workflow.mixin.injection import OutputsWithInjection
 from pyiron_workflow.nodes.composite import Composite
 
 if TYPE_CHECKING:
@@ -294,7 +295,7 @@ def _build_inputs(self):
         return self._build_io("inputs", self.inputs_map)
 
     @property
-    def outputs(self) -> Outputs:
+    def outputs(self) -> OutputsWithInjection:
         return self._build_outputs()
 
     def _build_outputs(self):
@@ -304,7 +305,7 @@ def _build_io(
         self,
         i_or_o: Literal["inputs", "outputs"],
         key_map: dict[str, str | None] | None,
-    ) -> Inputs | Outputs:
+    ) -> Inputs | OutputsWithInjection:
         """
         Build an IO panel for exposing child node IO to the outside world at the level
         of the composite node's IO.
@@ -320,10 +321,10 @@ def _build_io(
                 (which normally would be exposed) by providing a string-None map.
 
         Returns:
-            (Inputs|Outputs): The populated panel.
+            (Inputs|OutputsWithInjection): The populated panel.
         """
         key_map = {} if key_map is None else key_map
-        io = Inputs() if i_or_o == "inputs" else Outputs()
+        io = Inputs() if i_or_o == "inputs" else OutputsWithInjection()
         for node in self.children.values():
             panel = getattr(node, i_or_o)
             for channel in panel:

tests/unit/test_io.py

@@ -17,7 +17,7 @@
 )
 
 
-class Dummy(HasIO):
+class Dummy(HasIO[Outputs]):
     def __init__(self, label: str | None = "has_io"):
         super().__init__()
         self._label = label