[2119] Display expressions values in the Details view

Bug: #2119
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>

Author: pcdavid

CHANGELOG.adoc

@@ -26,11 +26,11 @@
 
 - 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.
 - https://github.com/eclipse-syson/syson/issues/2194[#2194] [diagrams] Properly report feedback messages to user when using _ISysMLMoveElementService_.
-- https://github.com/eclipse-syson/syson/issues/2182[#2182] [services] Provide a way for downstream applications to extend _ISysMLMoveElementService_;
+- https://github.com/eclipse-syson/syson/issues/2182[#2182] [services] Provide a way for downstream applications to extend _ISysMLMoveElementService_.
 - https://github.com/eclipse-syson/syson/issues/2240[#2240] [diagrams] Update the choice of _timeslice_ and _snapshot_ elements that can be created in the selection dialog of tools creating _timeslice_ and _snapshot_ elements.
 Before, the selection dialog option with selection allowed choosing between all _timeslice/snapshot_ types.
 Now, the choice is restricted to the _timeslice/snapshot_ type that match the graphical node type on which the tool is applied.
-
+- https://github.com/eclipse-syson/syson/issues/2119[#2119] [details] Display expressions values in the _Details_ view and allow to edit them from there.
 
 === New features
 

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysMLv2PropertiesConfigurer.java

@@ -79,6 +79,8 @@
 @Configuration
 public class SysMLv2PropertiesConfigurer implements IPropertiesDescriptionRegistryConfigurer {
 
+    private static final String CUSTOM_EXPRESSION_WIDGET_KEY = "syson:expression-value-widget";
+
     private static final String CORE_PROPERTIES = "Core Properties";
 
     private static final String ADVANCED_PROPERTIES = "Advanced Properties";
@@ -189,6 +191,7 @@ private FormDescription createDetailsViewForElement() {
         pageCore.getGroups().add(this.createExtraAcceptActionUsagePropertiesGroup());
         pageCore.getGroups().add(this.createExtraTransitionSourceTargetPropertiesGroup());
         pageCore.getGroups().add(this.createFeatureValuePropertiesGroup());
+        pageCore.getGroups().add(this.createExpressionPropertiesGroup());
 
         PageDescription pageAdvanced = FormFactory.eINSTANCE.createPageDescription();
         pageAdvanced.setName("SysON-DetailsView-Advanced");
@@ -203,6 +206,28 @@ private FormDescription createDetailsViewForElement() {
         return form;
     }
 
+    /**
+     * Creates a group to display the value of an Expression.
+     *
+     * @return a {@link GroupDescription}
+     */
+    private GroupDescription createExpressionPropertiesGroup() {
+        GroupDescription group = FormFactory.eINSTANCE.createGroupDescription();
+        group.setDisplayMode(GroupDisplayMode.LIST);
+        group.setName("Expression Value");
+        group.setLabelExpression("");
+        group.setSemanticCandidatesExpression(ServiceMethod.of0(DetailsViewService::getExpression).aqlSelf());
+
+        TextAreaDescription expressionWidget = FormFactory.eINSTANCE.createTextAreaDescription();
+        expressionWidget.setName("Expression");
+        expressionWidget.setLabelExpression(CUSTOM_EXPRESSION_WIDGET_KEY);
+        expressionWidget.setValueExpression(ServiceMethod.of0(DetailsViewService::getExpressionTextualRepresentation).aqlSelf());
+        expressionWidget.setIsEnabledExpression(AQLConstants.AQL_FALSE);
+
+        group.getChildren().add(expressionWidget);
+
+        return group;
+    }
 
     /**
      * Creates a group to display the value of a Feature or FeatureValue.

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/services/DetailsViewService.java

@@ -44,6 +44,7 @@
 import org.eclipse.syson.sysml.Annotation;
 import org.eclipse.syson.sysml.Comment;
 import org.eclipse.syson.sysml.ConjugatedPortDefinition;
+import org.eclipse.syson.sysml.Definition;
 import org.eclipse.syson.sysml.Documentation;
 import org.eclipse.syson.sysml.Element;
 import org.eclipse.syson.sysml.EndFeatureMembership;
@@ -55,6 +56,7 @@
 import org.eclipse.syson.sysml.FeatureValue;
 import org.eclipse.syson.sysml.Import;
 import org.eclipse.syson.sysml.Membership;
+import org.eclipse.syson.sysml.Namespace;
 import org.eclipse.syson.sysml.ParameterMembership;
 import org.eclipse.syson.sysml.ReferenceSubsetting;
 import org.eclipse.syson.sysml.ReferenceUsage;
@@ -68,6 +70,7 @@
 import org.eclipse.syson.sysml.SysmlPackage;
 import org.eclipse.syson.sysml.TransitionUsage;
 import org.eclipse.syson.sysml.Type;
+import org.eclipse.syson.sysml.Usage;
 import org.eclipse.syson.sysml.ViewUsage;
 import org.eclipse.syson.sysml.metamodel.services.ElementInitializerSwitch;
 import org.eclipse.syson.sysml.metamodel.services.MetamodelQueryElementService;
@@ -570,12 +573,16 @@ public Element setNewDocumentationValue(Element self, String newValue) {
      *            a {@link FeatureValue} or {@link Feature}
      * @return a {@link FeatureValue} or <code>null</code>
      */
-    public Element getFeatureValue(Element self) {
-        Element result = null;
+    public FeatureValue getFeatureValue(Element self) {
+        FeatureValue result = null;
         if (self instanceof FeatureValue featureValue && featureValue.getValue() != null) {
             result = featureValue;
         } else if (self instanceof Feature feature) {
-            result = this.metamodelQueryElementService.getValueExpression(feature).orElse(null);
+            result = feature.getOwnedRelationship().stream()
+                    .filter(FeatureValue.class::isInstance)
+                    .map(FeatureValue.class::cast)
+                    .findFirst()
+                    .orElse(null);
         }
         return result;
     }
@@ -626,6 +633,39 @@ private String getExpressionAsText(Expression expression) {
         return this.metamodelQueryElementService.getExpressionTextualRepresentation(expression);
     }
 
+    /**
+     * Gets the {@link ResultExpressionMembership} from a {@link Namespace} or a {@link ResultExpressionMembership}.
+     *
+     * @param self
+     *            a {@link Namespace} or a {@link ResultExpressionMembership}.
+     * @return a {@link ResultExpressionMembership} or <code>null</code>
+     */
+    public Element getResultExpression(Element self) {
+        Element result = null;
+        if (self instanceof ResultExpressionMembership expressionMembership && expressionMembership.getOwnedResultExpression() != null) {
+            result = expressionMembership;
+        } else if (self instanceof Namespace namespace && this.metamodelQueryElementService.getResultExpressionMembership(namespace) != null
+                && this.metamodelQueryElementService.getResultExpressionMembership(namespace).getOwnedResultExpression() != null) {
+            result = this.metamodelQueryElementService.getResultExpressionMembership(namespace);
+        }
+        return result;
+    }
+
+    /**
+     * Gets the {@link ResultExpressionMembership} from a {@link Namespace} or a {@link ResultExpressionMembership}.
+     *
+     * @param self
+     *            a {@link Namespace} or a {@link ResultExpressionMembership}.
+     * @return a {@link ResultExpressionMembership} or <code>null</code>
+     */
+    public Element getExpression(Element self) {
+        if (self instanceof Expression && !(self instanceof Usage) && !(self instanceof Definition)) {
+            return self;
+        } else {
+            return null;
+        }
+    }
+
     /**
      * Returns the element that owns the visibility feature of the given element.
      *

backend/services/syson-sysml-metamodel-services/src/main/java/org/eclipse/syson/sysml/metamodel/services/MetamodelQueryElementService.java

@@ -27,9 +27,11 @@
 import org.eclipse.syson.sysml.Feature;
 import org.eclipse.syson.sysml.FeatureValue;
 import org.eclipse.syson.sysml.FramedConcernMembership;
+import org.eclipse.syson.sysml.Namespace;
 import org.eclipse.syson.sysml.OwningMembership;
 import org.eclipse.syson.sysml.PartUsage;
 import org.eclipse.syson.sysml.ReferenceUsage;
+import org.eclipse.syson.sysml.ResultExpressionMembership;
 import org.eclipse.syson.sysml.StakeholderMembership;
 import org.eclipse.syson.sysml.SubjectMembership;
 import org.eclipse.syson.sysml.SysmlFactory;
@@ -306,4 +308,20 @@ public ConcernUsage getFramedConcernTarget(FramedConcernMembership framedConcern
         }
         return null;
     }
+
+    /**
+     * Get the {@link ResultExpressionMembership} contained inside a given {@link Namespace}.
+     *
+     * @param namespace
+     *            a given {@link Namespace}.
+     * @return a {@link ResultExpressionMembership}, or <code>null</code> if not found.
+     */
+    public ResultExpressionMembership getResultExpressionMembership(Namespace namespace) {
+        return namespace.getOwnedMembership().stream()
+                .filter(ResultExpressionMembership.class::isInstance)
+                .map(ResultExpressionMembership.class::cast)
+                .findFirst()
+                .orElse(null);
+    }
+
 }

doc/content/modules/user-manual/assets/images/expression-details.png

@@ -19,6 +19,10 @@ a|image::explorer-expression-internals-hidden.png[Internals hidden (default)]
 a|image::explorer-expression-internals-visible.png[Internals visible]
 |===
 
+When an `Expression` element is selected(for example from the {explorer} view), the {details}} view displays its textual representation, with a button to open the expression edition modal (see below) directly on it:
++
+image::expression-details.png[Expression value displayed in the _Details_ veiw, width=80%]
+
 == Creation
 
 To _create_ an expression, invoke the _New expression_ context menu action on a compatible element (supported elements are `Attributes`, `Constraints` and `Transitions`).

doc/content/modules/user-manual/pages/features/expressions.adoc

@@ -66,6 +66,11 @@ To _edit_ an existing expression, simply invoke the _Edit expression_ context me
 +
 To _delete_ an existing expression, you can simply invoke the normal _Delete_ menu item action on the expression itself or the new _Delete expression_ on its parent element.
 
+* In the _Details_ view:
+
+** When an `Expression` element is selected (for example from the _Explorer_ view), the _Details_ view displays its textual representation, with a button to open the expression edition modal (see above) directly on it:
++
+image::expression-details.png[Expression value displayed in the _Details_ veiw, width=80%]
 
 == Bug fixes
 

doc/content/modules/user-manual/pages/release-notes/2026.7.0.adoc

@@ -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
@@ -12,6 +12,7 @@
  *******************************************************************************/
 
 import { DataExtension, ExtensionRegistryMergeStrategy } from '@eclipse-sirius/sirius-components-core';
+import { widgetContributionExtensionPoint } from '@eclipse-sirius/sirius-components-forms';
 import { omniboxCommandOverrideContributionExtensionPoint } from '@eclipse-sirius/sirius-components-omnibox';
 import { treeItemContextMenuEntryOverrideExtensionPoint } from '@eclipse-sirius/sirius-components-trees';
 import {
@@ -37,6 +38,9 @@ export class SysONExtensionRegistryMergeStrategy
     if (identifier === treeItemContextMenuEntryOverrideExtensionPoint.identifier) {
       return this.mergeTreeItemContributions(existingValues, newValues);
     }
+    if (identifier === widgetContributionExtensionPoint.identifier) {
+      return this.mergeWidgetContributions(existingValues, newValues);
+    }
     return newValues;
   }
 
@@ -69,4 +73,14 @@ export class SysONExtensionRegistryMergeStrategy
       data: [...existingContributions.data, ...newContributions.data],
     };
   }
+
+  private mergeWidgetContributions(
+    existingContributions: DataExtension<any>,
+    newContributions: DataExtension<any>
+  ): DataExtension<any> {
+    return {
+      identifier: `syson_${widgetContributionExtensionPoint.identifier}`,
+      data: [...existingContributions.data, ...newContributions.data],
+    };
+  }
 }