[2232] Fix SysOn view model to be serializable

CHANGELOG.adoc

@@ -14,6 +14,8 @@
 
 === Bug fixes
 
+- https://github.com/eclipse-syson/syson/issues/2232[#2232] [configuration] Fix a serialization problem of the View models of SysON representations.
+
 === Improvements
 
 - https://github.com/eclipse-syson/syson/issues/2198[#2198] [diagrams] Improve diagram-to-diagram drag and drop to support dropping multiple graphical nodes at once, leveraging Sirius Web's `droppedNodes` and `droppedElements` variables.

backend/views/syson-common-view/src/main/java/org/eclipse/syson/common/view/api/IViewDescriptionProvider.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2024, 2025 Obeo.
+ * Copyright (c) 2024, 2026 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
@@ -13,12 +13,14 @@
 package org.eclipse.syson.common.view.api;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.sirius.components.emf.ResourceMetadataAdapter;
 import org.eclipse.sirius.components.emf.services.IDAdapter;
 import org.eclipse.sirius.components.emf.services.JSONResourceFactory;
+import org.eclipse.sirius.components.view.ColorPalette;
 import org.eclipse.sirius.components.view.RepresentationDescription;
 import org.eclipse.sirius.components.view.View;
 import org.eclipse.sirius.components.view.builder.generated.view.ViewBuilder;
@@ -55,6 +57,9 @@ default List<View> getRepresentationDescriptions() {
         View view = viewBuilder.build();
         IColorProvider colorProvider = new ColorProvider(view);
 
+        this.buildColorPalette()
+                .ifPresent(colorPalette -> view.getColorPalettes().add(colorPalette));
+
         // Create org.eclipse.sirius.components.view.RepresentationDescription
         IRepresentationDescriptionProvider viewDiagramDescriptionProvider = this.getRepresentationDescriptionProvider();
         RepresentationDescription viewRepresentationDescription = viewDiagramDescriptionProvider.create(colorProvider);
@@ -73,4 +78,13 @@ default List<View> getRepresentationDescriptions() {
 
         return List.of(view);
     }
+
+    /**
+     * Creates an optional color palette for this {@link View}.
+     *
+     * @return an {@link Optional} color palette.
+     */
+    default Optional<ColorPalette> buildColorPalette() {
+        return Optional.empty();
+    }
 }

backend/views/syson-standard-diagrams-view/src/main/java/org/eclipse/syson/standard/diagrams/view/SDVDescriptionProvider.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2023, 2025 Obeo.
+ * Copyright (c) 2023, 2026 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
@@ -12,8 +12,14 @@
  *******************************************************************************/
 package org.eclipse.syson.standard.diagrams.view;
 
+import java.util.Optional;
+
+import org.eclipse.sirius.components.view.ColorPalette;
+import org.eclipse.sirius.components.view.builder.generated.view.ColorPaletteBuilder;
+import org.eclipse.sirius.components.view.builder.generated.view.ViewBuilders;
 import org.eclipse.sirius.components.view.builder.providers.IRepresentationDescriptionProvider;
 import org.eclipse.syson.common.view.api.IViewDescriptionProvider;
+import org.eclipse.syson.diagram.common.view.nodes.AddYourFirstElement;
 import org.springframework.stereotype.Service;
 
 /**
@@ -37,4 +43,14 @@ public String getViewId() {
     public IRepresentationDescriptionProvider getRepresentationDescriptionProvider() {
         return new SDVDiagramDescriptionProvider();
     }
+
+    @Override
+    public Optional<ColorPalette> buildColorPalette() {
+        ColorPalette colorPalette = new ColorPaletteBuilder().colors(new ViewBuilders().newFixedColor()
+                        .name(AddYourFirstElement.COLOR_NAME)
+                        .value("url(" + AddYourFirstElement.BASE64 + ") no-repeat center center / contain")
+                        .build())
+                .build();
+        return Optional.of(colorPalette);
+    }
 }

backend/views/syson-standard-diagrams-view/src/main/java/org/eclipse/syson/standard/diagrams/view/SDVDiagramDescriptionProvider.java

@@ -321,14 +321,10 @@ public class SDVDiagramDescriptionProvider implements IRepresentationDescription
     @Override
     public RepresentationDescription create(IColorProvider colorProvider) {
         String domainType = SysMLMetamodelHelper.buildQualifiedName(SysmlPackage.eINSTANCE.getNamespace());
-
         var emptyDiagramStyle = new DiagramBuilders().newConditionalDiagramStyle()
                 .condition("aql:self.exposedElement->size() == 0 and editingContext.isDiagramEmpty(diagramContext, previousDiagram, self.exposedElement->size())")
                 .style(new DiagramBuilders().newDiagramStyleDescription()
-                        .background(this.viewBuilderHelper.newFixedColor()
-                                .name("AddYourFirstElement")
-                                .value("url(" + AddYourFirstElement.BASE64 + ") no-repeat center center / contain")
-                                .build())
+                        .background(colorProvider.getColor(AddYourFirstElement.COLOR_NAME))
                         .build())
                 .build();