Merge pull request #145 from scipp/save-parameters

Set/get parameters input widget values.

docs/api-reference/index.md

@@ -30,6 +30,7 @@
    logging
    nexus
    streaming
+   ui
    uncertainty
    widgets
 ```

src/ess/reduce/ui.py

@@ -10,6 +10,7 @@
 
 from .parameter import Parameter
 from .widgets import SwitchWidget, create_parameter_widget, default_layout
+from .widgets._base import get_fields, set_fields
 from .workflow import (
     Key,
     assign_parameter_values,
@@ -81,11 +82,13 @@ def _refresh_input_box(_: widgets.Button):
             self._input_widgets.clear()
             self._input_widgets.update(
                 {
-                    node: widgets.HBox([create_parameter_widget(parameter)])
-                    for node, parameter in registry_getter().items()
+                    node: create_parameter_widget(parameter)
+                    for node, parameter in new_input_parameters.items()
                 }
             )
-            self._input_box.children = list(self._input_widgets.values())
+            self._input_box.children = [
+                widgets.HBox([widget]) for widget in self._input_widgets.values()
+            ]
 
         self.parameter_refresh_button.on_click(_refresh_input_box)
 
@@ -97,8 +100,7 @@ def value(self) -> dict[Key, Any]:
         return {
             node: widget.value
             for node, widget_box in self._input_widgets.items()
-            if (not isinstance((widget := widget_box.children[0]), SwitchWidget))
-            or widget.enabled
+            if (not isinstance((widget := widget_box), SwitchWidget)) or widget.enabled
         }
 
 
@@ -232,3 +234,80 @@ def refresh_workflow_box(change) -> None:
     workflow_selection_box = widgets.HBox([workflow_select], layout=default_layout)
     workflow_box = widgets.Box(layout=default_layout)
     return widgets.VBox([workflow_selection_box, workflow_box])
+
+
+def _get_parameter_box(widget: WorkflowWidget | ParameterBox) -> ParameterBox:
+    if isinstance(widget, WorkflowWidget):
+        return widget.parameter_box
+    elif isinstance(widget, ParameterBox):
+        return widget
+    else:
+        raise TypeError(
+            f"Expected target_widget to be a WorkflowWidget or ParameterBox, "
+            f"got {type(widget)}."
+        )
+
+
+def set_parameter_widget_values(
+    widget: WorkflowWidget | ParameterBox, new_parameter_values: dict[type, Any]
+) -> None:
+    """Set the values of the input widgets in the target widget.
+
+    Nodes that don't exist in the input widgets will be ignored.
+
+    Example
+    -------
+    {
+        'WavelengthBins': {'start': 1.0, 'stop': 14.0, 'nbins': 500}
+    }
+
+    Parameters
+    ----------
+    widget:
+        The widget containing the input widgets.
+    new_parameter_values:
+        A dictionary of values/state to set each fields/state or value of input widgets.
+
+    Raises
+    ------
+    TypeError:
+        If the widget is not a WorkflowWidget or a ParameterBox.
+
+    """
+    parameter_box = _get_parameter_box(widget)
+    # Walk through the existing input widgets and set the values
+    # ``node`s that don't exist in the input widgets will be ignored.
+    for node, widget in parameter_box._input_widgets.items():
+        if node in new_parameter_values:
+            # We shouldn't use `get` here because ``None`` is a valid value.
+            set_fields(widget, new_parameter_values[node])
+
+
+def get_parameter_widget_values(
+    widget: WorkflowWidget | ParameterBox,
+) -> dict[type, Any]:
+    """Return the current values of the input widgets in the target widget.
+
+    The result of this function can be used to set the values of the input widgets
+    using the :py:func:`~set_parameter_widget_values` function.
+
+    Parameters
+    ----------
+    widget:
+        The widget containing the input widgets.
+
+    Returns
+    -------
+    :
+        A dictionary of the current values/state of each input widget.
+
+    Raises
+    ------
+    TypeError:
+        If the widget is not a WorkflowWidget or a ParameterBox.
+
+    """
+    return {
+        node: get_fields(widget)
+        for node, widget in _get_parameter_box(widget)._input_widgets.items()
+    }

src/ess/reduce/widgets/_base.py

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2024 Scipp contributors (https://github.com/scipp)
+import warnings
+from typing import Any, Protocol, runtime_checkable
+
+from ipywidgets import Widget
+
+
+@runtime_checkable
+class WidgetWithFieldsProtocol(Protocol):
+    def set_fields(self, new_values: dict[str, Any]) -> None: ...
+
+    def get_fields(self) -> dict[str, Any]: ...
+
+
+class WidgetWithFieldsMixin:
+    def set_fields(self, new_values: dict[str, Any]) -> None:
+        # Extract valid fields
+        new_field_names = set(new_values.keys())
+        valid_field_names = new_field_names & set(self.fields.keys())
+        # Warn for invalid fields
+        invalid_field_names = new_field_names - valid_field_names
+        for field_name in invalid_field_names:
+            warning_msg = f"Cannot set field '{field_name}'."
+            " The field does not exist in the widget."
+            "The field value will be ignored."
+            warnings.warn(warning_msg, UserWarning, stacklevel=1)
+        # Set valid fields
+        for field_name in valid_field_names:
+            self.fields[field_name].value = new_values[field_name]
+
+    def get_fields(self) -> dict[str, Any]:
+        return {
+            field_name: field_sub_widget.value
+            for field_name, field_sub_widget in self.fields.items()
+        }
+
+
+def _has_widget_value_setter(widget: Widget) -> bool:
+    widget_type = type(widget)
+    return (
+        widget_property := getattr(widget_type, 'value', None)
+    ) is not None and getattr(widget_property, 'fset', None) is not None
+
+
+def set_fields(widget: Widget, new_values: Any) -> None:
+    if isinstance(widget, WidgetWithFieldsProtocol) and isinstance(new_values, dict):
+        widget.set_fields(new_values)
+    elif _has_widget_value_setter(widget):
+        widget.value = new_values
+    else:
+        warnings.warn(
+            f"Cannot set value or fields for widget of type {type(widget)}."
+            " The new_value(s) will be ignored.",
+            UserWarning,
+            stacklevel=1,
+        )
+
+
+def get_fields(widget: Widget) -> Any:
+    if isinstance(widget, WidgetWithFieldsProtocol):
+        return widget.get_fields()
+    return widget.value

src/ess/reduce/widgets/_binedges_widget.py

@@ -3,6 +3,8 @@
 import ipywidgets as ipw
 import scipp as sc
 
+from ._base import WidgetWithFieldsMixin
+
 UNITS_LIBRARY = {
     "wavelength": {"options": ("angstrom", "nm")},
     "Q": {"options": ("1/angstrom", "1/nm")},
@@ -19,7 +21,7 @@
 }
 
 
-class BinEdgesWidget(ipw.HBox, ipw.ValueWidget):
+class BinEdgesWidget(ipw.HBox, ipw.ValueWidget, WidgetWithFieldsMixin):
     def __init__(
         self,
         name: str,

src/ess/reduce/widgets/_bounds_widget.py

@@ -4,9 +4,10 @@
 from ipywidgets import FloatText, GridBox, Label, Text, ValueWidget
 
 from ..parameter import ParamWithBounds
+from ._base import WidgetWithFieldsMixin
 
 
-class BoundsWidget(GridBox, ValueWidget):
+class BoundsWidget(GridBox, ValueWidget, WidgetWithFieldsMixin):
     def __init__(self):
         super().__init__()
 

src/ess/reduce/widgets/_linspace_widget.py

@@ -3,8 +3,10 @@
 import scipp as sc
 from ipywidgets import FloatText, GridBox, IntText, Label, ValueWidget
 
+from ._base import WidgetWithFieldsMixin
 
-class LinspaceWidget(GridBox, ValueWidget):
+
+class LinspaceWidget(GridBox, ValueWidget, WidgetWithFieldsMixin):
     def __init__(self, dim: str, unit: str):
         super().__init__()
 

src/ess/reduce/widgets/_vector_widget.py

@@ -4,8 +4,10 @@
 import scipp as sc
 from ipywidgets import FloatText, HBox, Label, Text, ValueWidget
 
+from ._base import WidgetWithFieldsMixin
 
-class VectorWidget(HBox, ValueWidget):
+
+class VectorWidget(HBox, ValueWidget, WidgetWithFieldsMixin):
     def __init__(self, name: str, variable: sc.Variable, components: str):
         super().__init__()
 

tests/widget_test.py

@@ -79,7 +79,7 @@ def provider_with_optional(a: OptionalInt, b: OptionalFloat) -> str:
 
 
 def _get_param_widget(widget: WorkflowWidget, param_type: type) -> Any:
-    return widget.parameter_box._input_widgets[param_type].children[0]
+    return widget.parameter_box._input_widgets[param_type]
 
 
 def test_parameter_default_value_test() -> None: