Add tools property and entrypoint for workflows

src/aiida/orm/nodes/process/workflow/workchain.py

@@ -8,12 +8,16 @@
 ###########################################################################
 """Module with `Node` sub class for workchain processes."""
 
-from typing import Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple
 
+from aiida.common import exceptions
 from aiida.common.lang import classproperty
 
 from .workflow import WorkflowNode
 
+if TYPE_CHECKING:
+    from aiida.tools.workflows import WorkflowTools
+
 __all__ = ('WorkChainNode',)
 
 
@@ -22,6 +26,40 @@
 
     STEPPER_STATE_INFO_KEY = 'stepper_state_info'
 
+    # An optional entry point for a CalculationTools instance
+    _tools = None
+
+    @property
+    def tools(self) -> 'WorkflowTools':
+        """Return the calculation tools that are registered for the process type associated with this calculation.
+
+        If the entry point name stored in the `process_type` of the CalcJobNode has an accompanying entry point in the
+        `aiida.tools.calculations` entry point category, it will attempt to load the entry point and instantiate it
+        passing the node to the constructor. If the entry point does not exist, cannot be resolved or loaded, a warning
+        will be logged and the base CalculationTools class will be instantiated and returned.
+
+        :return: CalculationTools instance
+        """
+        from aiida.plugins.entry_point import get_entry_point_from_string, is_valid_entry_point_string, load_entry_point
+        from aiida.tools.workflows import WorkflowTools
+
+        if self._tools is None:
+            entry_point_string = self.process_type
+
+            if entry_point_string and is_valid_entry_point_string(entry_point_string):
+                entry_point = get_entry_point_from_string(entry_point_string)
+
+                try:
+                    tools_class = load_entry_point('aiida.tools.workflows', entry_point.name)
+                    self._tools = tools_class(self)
+                except exceptions.EntryPointError as exception:
+                    self._tools = WorkflowTools(self)
+                    self.logger.warning(
+                        f'could not load the workflow tools entry point {entry_point.name}: {exception}'
+                    )
+
+        return self._tools
+
     @classproperty
     def _updatable_attributes(cls) -> Tuple[str, ...]:  # type: ignore[override]  # noqa: N805
         return super()._updatable_attributes + (cls.STEPPER_STATE_INFO_KEY,)

src/aiida/tools/workflows/__init__.py

@@ -0,0 +1,21 @@
+###########################################################################
+# Copyright (c), The AiiDA team. All rights reserved.                     #
+# This file is part of the AiiDA code.                                    #
+#                                                                         #
+# The code is hosted on GitHub at https://github.com/aiidateam/aiida-core #
+# For further information on the license, see the LICENSE.txt file        #
+# For further information please visit http://www.aiida.net               #
+###########################################################################
+"""Workflow tool plugins for Workflow classes."""
+
+# AUTO-GENERATED
+
+# fmt: off
+
+from .base import *
+
+__all__ = (
+    'WorkflowTools',
+)
+
+# fmt: on

src/aiida/tools/workflows/base.py

@@ -0,0 +1,22 @@
+###########################################################################
+# Copyright (c), The AiiDA team. All rights reserved.                     #
+# This file is part of the AiiDA code.                                    #
+#                                                                         #
+# The code is hosted on GitHub at https://github.com/aiidateam/aiida-core #
+# For further information on the license, see the LICENSE.txt file        #
+# For further information please visit http://www.aiida.net               #
+###########################################################################
+"""Base class for WorkflowTools
+
+Sub-classes can be registered in the `aiida.tools.calculations` category to enable the `CalcJobNode` class from being
+able to find the tools plugin, load it and expose it through the `tools` property of the `CalcJobNode`.
+"""
+
+__all__ = ('WorkflowTools',)
+
+
+class WorkflowTools:
+    """Base class for WorkflowTools."""
+
+    def __init__(self, node):
+        self._node = node