[core] ChoiceParam: add option to serialize overriden values

Introduce a new `saveValuesOverride` parameter on desc.ChoiceParam to define
whether to serialize the list of possible values if they have been overridden at runtime.

meshroom/core/attribute.py

@@ -472,11 +472,16 @@ class PushButtonParam(Attribute):
 
 class ChoiceParam(Attribute):
 
-    def __init__(self, node, attributeDesc, isOutput, root=None, parent=None):
+    def __init__(self, node, attributeDesc: desc.ChoiceParam, isOutput, root=None, parent=None):
         super(ChoiceParam, self).__init__(node, attributeDesc, isOutput, root, parent)
         self._values = None
 
+    def __len__(self):
+        return len(self.getValues())
+
     def getValues(self):
+        if (linkParam := self.getLinkParam()) is not None:
+            return linkParam.getValues()
         return self._values if self._values is not None else self.desc._values
 
     def conformValue(self, val):
@@ -494,6 +499,15 @@ class ChoiceParam(Attribute):
             raise ValueError("Non exclusive ChoiceParam value should be iterable (param:{}, value:{}, type:{})".
                              format(self.name, value, type(value)))
         return [self.conformValue(v) for v in value]
+    
+    def _set_value(self, value):
+        # Handle alternative serialization for ChoiceParam with overriden values.
+        serializedValueWithValuesOverrides = isinstance(value, dict)
+        if serializedValueWithValuesOverrides:
+            super()._set_value(value[self.desc._OVERRIDE_SERIALIZATION_KEY_VALUE])
+            self.setValues(value[self.desc._OVERRIDE_SERIALIZATION_KEY_VALUES])
+        else:
+            super()._set_value(value)
 
     def setValues(self, values):
         if values == self._values:
@@ -501,9 +515,18 @@ class ChoiceParam(Attribute):
         self._values = values
         self.valuesChanged.emit()
 
-    def __len__(self):
+    def getExportValue(self):
-        return len(self.getValues())
+        useStandardSerialization = self.isLink or not self.desc._saveValuesOverride or self._values is None
 
+        if useStandardSerialization:
+            return super().getExportValue()
+
+        return {
+            self.desc._OVERRIDE_SERIALIZATION_KEY_VALUE: self._value,
+            self.desc._OVERRIDE_SERIALIZATION_KEY_VALUES: self._values,
+        }
+
+    value = Property(Variant, Attribute._get_value, _set_value, notify=Attribute.valueChanged)
     valuesChanged = Signal()
     values = Property(Variant, getValues, setValues, notify=valuesChanged)
 

meshroom/core/desc/attribute.py

@@ -411,16 +411,33 @@ class PushButtonParam(Param):
 
 class ChoiceParam(Param):
     """
+    ChoiceParam is an Attribute that allows to choose a value among a list of possible values.
+
+    When using `exclusive=True`, the value is a single element of the list of possible values.
+    When using `exclusive=False`, the value is a list of elements of the list of possible values.
+    
+    Despite this being the standard behavior, ChoiceParam also supports custom value: it is possible to set any value, 
+    even outside list of possible values.
+
+    The list of possible values on a ChoiceParam instance can be overriden at runtime. 
+    If those changes needs to be persisted, `saveValuesOverride` should be set to True.
     """
-    def __init__(self, name, label, description, value, values, exclusive=True, group="allParams", joinChar=" ",
+
-                 advanced=False, enabled=True, invalidate=True, semantic="", validValue=True, errorMessage="",
+    # Keys for values override serialization schema (saveValuesOverride=True).
+    _OVERRIDE_SERIALIZATION_KEY_VALUE = "__ChoiceParam_value__"
+    _OVERRIDE_SERIALIZATION_KEY_VALUES = "__ChoiceParam_values__"
+
+    def __init__(self, name: str, label: str, description: str, value, values, exclusive=True, saveValuesOverride=False, 
+                 group="allParams", joinChar=" ", advanced=False, enabled=True, invalidate=True, semantic="", 
+                 validValue=True, errorMessage="",
                  visible=True, exposed=False):
-        assert values
+
         super(ChoiceParam, self).__init__(name=name, label=label, description=description, value=value,
                                           group=group, advanced=advanced, enabled=enabled, invalidate=invalidate,
                                           semantic=semantic, validValue=validValue, errorMessage=errorMessage,
                                           visible=visible, exposed=exposed)
         self._values = values
+        self._saveValuesOverride = saveValuesOverride
         self._exclusive = exclusive
         self._joinChar = joinChar
         if self._values:
@@ -447,6 +464,11 @@ class ChoiceParam(Param):
     def validateValue(self, value):
         if value is None:
             return value
+
+        serializedWithValuesOverride = isinstance(value, dict)
+        if serializedWithValuesOverride:
+            value = value[ChoiceParam._OVERRIDE_SERIALIZATION_KEY_VALUE]
+
         if self.exclusive:
             return self.conformValue(value)
 

tests/test_attributeChoiceParam.py

@@ -0,0 +1,169 @@
+from meshroom.core import desc, registerNodeType, unregisterNodeType
+from meshroom.core.graph import Graph, loadGraph
+
+
+class NodeWithChoiceParams(desc.Node):
+    inputs = [
+        desc.ChoiceParam(
+            name="choice",
+            label="Choice Default Serialization",
+            description="A choice parameter with standard serialization",
+            value="A",
+            values=["A", "B", "C"],
+            saveValuesOverride=False,
+            exclusive=True,
+            exposed=True,
+        ),
+        desc.ChoiceParam(
+            name="choiceMulti",
+            label="Choice Default Serialization",
+            description="A choice parameter with standard serialization",
+            value=["A"],
+            values=["A", "B", "C"],
+            saveValuesOverride=False,
+            exclusive=False,
+            exposed=True,
+        ),
+    ]
+
+class NodeWithChoiceParamsSavingValuesOverride(desc.Node):
+    inputs = [
+        desc.ChoiceParam(
+            name="choice",
+            label="Choice Custom Serialization",
+            description="A choice parameter with serialization of overriden values",
+            value="A",
+            values=["A", "B", "C"],
+            saveValuesOverride=True,
+            exclusive=True,
+            exposed=True,
+        ),
+        desc.ChoiceParam(
+            name="choiceMulti",
+            label="Choice Custom Serialization",
+            description="A choice parameter with serialization of overriden values",
+            value=["A"],
+            values=["A", "B", "C"],
+            saveValuesOverride=True,
+            exclusive=False,
+            exposed=True,
+        )
+    ]
+
+
+class TestChoiceParam:
+    @classmethod
+    def setup_class(cls):
+        registerNodeType(NodeWithChoiceParams)
+
+    @classmethod
+    def teardown_class(cls):
+        unregisterNodeType(NodeWithChoiceParams)
+
+    def test_customValueIsSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+
+        node = graph.addNewNode(NodeWithChoiceParams.__name__)
+        node.choice.value = "CustomValue"
+        graph.save()
+
+        loadedGraph = loadGraph(graph.filepath)
+        assert loadedGraph.node(node.name).choice.value == "CustomValue"
+
+    def test_customMultiValueIsSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+
+        node = graph.addNewNode(NodeWithChoiceParams.__name__)
+        node.choiceMulti.value = ["custom", "value"]
+        graph.save()
+
+        loadedGraph = loadGraph(graph.filepath)
+        assert loadedGraph.node(node.name).choiceMulti.value == ["custom", "value"]
+
+    def test_overridenValuesAreNotSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+        node = graph.addNewNode(NodeWithChoiceParams.__name__)
+        node.choice.values = ["D", "E", "F"]
+        
+        graph.save()
+        loadedGraph = loadGraph(graph.filepath)
+
+        assert loadedGraph.node(node.name).choice.values == ["A", "B", "C"]
+
+    def test_connectionPropagatesOverridenValues(self):
+        graph = Graph("")
+
+        nodeA = graph.addNewNode(NodeWithChoiceParams.__name__)
+        nodeB = graph.addNewNode(NodeWithChoiceParams.__name__)
+        nodeA.choice.values = ["D", "E", "F"]
+        graph.addEdge(nodeA.choice, nodeB.choice)
+
+        assert nodeB.choice.values == ["D", "E", "F"]
+
+    def test_connectionsAreSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+        nodeA = graph.addNewNode(NodeWithChoiceParams.__name__)
+        nodeB = graph.addNewNode(NodeWithChoiceParams.__name__)
+        graph.addEdge(nodeA.choice, nodeB.choice)
+        graph.addEdge(nodeA.choiceMulti, nodeB.choiceMulti)
+
+        graph.save()
+
+        loadedGraph = loadGraph(graph.filepath)
+        loadedNodeA = loadedGraph.node(nodeA.name)
+        loadedNodeB = loadedGraph.node(nodeB.name)
+        assert loadedNodeB.choice.linkParam == loadedNodeA.choice
+        assert loadedNodeB.choiceMulti.linkParam == loadedNodeA.choiceMulti
+
+
+class TestChoiceParamSavingCustomValues:
+    @classmethod
+    def setup_class(cls):
+        registerNodeType(NodeWithChoiceParamsSavingValuesOverride)
+
+    @classmethod
+    def teardown_class(cls):
+        unregisterNodeType(NodeWithChoiceParamsSavingValuesOverride)
+
+    def test_customValueIsSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+
+        node = graph.addNewNode(NodeWithChoiceParamsSavingValuesOverride.__name__)
+        node.choice.value = "CustomValue"
+        node.choiceMulti.value = ["custom", "value"]
+        graph.save()
+
+        loadedGraph = loadGraph(graph.filepath)
+        assert loadedGraph.node(node.name).choice.value == "CustomValue"
+        assert loadedGraph.node(node.name).choiceMulti.value == ["custom", "value"]
+
+
+    def test_overridenValuesAreSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+        node = graph.addNewNode(NodeWithChoiceParamsSavingValuesOverride.__name__)
+        node.choice.values = ["D", "E", "F"]
+        node.choiceMulti.values = ["D", "E", "F"]
+        
+        graph.save()
+        loadedGraph = loadGraph(graph.filepath)
+
+        loadedNode = loadedGraph.node(node.name)
+
+        assert loadedNode.choice.values == ["D", "E", "F"]
+        assert loadedNode.choiceMulti.values == ["D", "E", "F"]
+
+
+    def test_connectionsAreSerialized(self, graphSavedOnDisk):
+        graph: Graph = graphSavedOnDisk
+        nodeA = graph.addNewNode(NodeWithChoiceParamsSavingValuesOverride.__name__)
+        nodeB = graph.addNewNode(NodeWithChoiceParamsSavingValuesOverride.__name__)
+        graph.addEdge(nodeA.choice, nodeB.choice)
+        graph.addEdge(nodeA.choiceMulti, nodeB.choiceMulti)
+
+        graph.save()
+
+        loadedGraph = loadGraph(graph.filepath)
+        loadedNodeA = loadedGraph.node(nodeA.name)
+        loadedNodeB = loadedGraph.node(nodeB.name)
+        assert loadedNodeB.choice.linkParam == loadedNodeA.choice
+        assert loadedNodeB.choiceMulti.linkParam == loadedNodeA.choiceMulti