Add validation reason and distinguish between live and batch validation (#200)

eclipse-glsp/glsp#980

Author: planger

CHANGELOG.md

@@ -5,7 +5,7 @@
 ### Changes
 
 - [graph] Updated the Graph model and add Layoutable interface [#175](https://github.com/eclipse-glsp/glsp-server/pull/175) - Contributed on behalf of STMicroelectronics
-- [layout] Extend `ComputedBoundsAction` to also provide route data for client-side routed edges and store source/target point  in the `args` map [#181](https://github.com/eclipse-glsp/glsp-server/pull/181)
+- [layout] Extend `ComputedBoundsAction` to also provide route data for client-side routed edges and store source/target point in the `args` map [#181](https://github.com/eclipse-glsp/glsp-server/pull/181)
 - [websocket] Remove listing on `stdin` from `WebsocketServerLauncher` [#189](https://github.com/eclipse-glsp/glsp-server/pull/189)
 - [diagram] Fixed a bug that prevented stable ids within one session when using the `IdKeeperAdapter` [#192](https://github.com/eclipse-glsp/glsp-server/pull/192) - Contributed on behalf of STMicroelectronics
 
@@ -23,6 +23,7 @@
   - EMFModelState and EMFNotationModelState are now interfaces instead of classes
   - EMFModelStateImpl and EMFNotationModelStateImpl classes have been added
   - Related Modules have been updated to inject these GModelState sub-types as a Singleton
+- [validation] Add explicit support and API for live and batch validation [#200](https://github.com/eclipse-glsp/glsp-server/pull/200)
 
 ## [v1.0.0 - 30/06/2022](https://github.com/eclipse-glsp/glsp-server/releases/tag/v1.0.0)
 

examples/org.eclipse.glsp.example.workflow/src/org/eclipse/glsp/example/workflow/marker/WorkflowModelValidator.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019-2022 EclipseSource and others.
+ * Copyright (c) 2019-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -39,48 +39,47 @@ public class WorkflowModelValidator implements ModelValidator {
    protected GModelState modelState;
 
    @Override
-   public List<Marker> validate(final GModelElement... elements) {
+   public List<Marker> doLiveValidation(final GModelElement element) {
       List<Marker> markers = new ArrayList<>();
-
-      for (GModelElement element : elements) {
-         if (element instanceof TaskNode) {
-            markers.addAll(validateTaskNode(modelState, element));
-         } else if (element instanceof ActivityNode) {
-            ActivityNode activityNode = (ActivityNode) element;
-            if ("decisionNode".equals(activityNode.getNodeType())) {
-               markers.addAll(validateDecisionNode(modelState, element));
-            } else if ("mergeNode".equals(activityNode.getNodeType())) {
-               markers.addAll(validateMergeNode(modelState, element));
-            }
-         }
-         if (element.getChildren() != null) {
-            markers.addAll(validate(element.getChildren().toArray(new GModelElement[element.getChildren().size()])));
+      if (element instanceof ActivityNode) {
+         ActivityNode activityNode = (ActivityNode) element;
+         if ("decisionNode".equals(activityNode.getNodeType())) {
+            markers.addAll(validateDecisionNode(element));
+         } else if ("mergeNode".equals(activityNode.getNodeType())) {
+            markers.addAll(validateMergeNode(element));
          }
       }
       return markers;
    }
 
-   private static List<Marker> validateTaskNode(final GModelState modelState, final GModelElement taskNode) {
+   @Override
+   public List<Marker> doBatchValidation(final GModelElement element) {
+      List<Marker> markers = new ArrayList<>();
+      if (element instanceof TaskNode) {
+         markers.addAll(validateTaskNode(element));
+      }
+      return markers;
+   }
+
+   private List<Marker> validateTaskNode(final GModelElement taskNode) {
       List<Marker> markers = new ArrayList<>();
-      validateTaskNode_isAutomated(modelState, taskNode).ifPresent(m -> markers.add(m));
-      validateTaskNode_labelStartsUpperCase(modelState, taskNode).ifPresent(m -> markers.add(m));
+      validateTaskNode_isAutomated(taskNode).ifPresent(m -> markers.add(m));
+      validateTaskNode_labelStartsUpperCase(taskNode).ifPresent(m -> markers.add(m));
       return markers;
    }
 
    @SuppressWarnings("checkstyle:MethodName")
-   private static Optional<Marker> validateTaskNode_isAutomated(final GModelState modelState,
-      final GModelElement element) {
+   private Optional<Marker> validateTaskNode_isAutomated(final GModelElement element) {
       TaskNode taskNode = (TaskNode) element;
       if ("automated".equals(taskNode.getTaskType())) {
-         return Optional
-            .of(new Marker("Automated task", "This is an automated task", element.getId(), MarkerKind.INFO));
+         String id = element.getId();
+         return Optional.of(new Marker("Automated task", "This is an automated task", id, MarkerKind.INFO));
       }
       return Optional.empty();
    }
 
    @SuppressWarnings("checkstyle:MethodName")
-   private static Optional<Marker> validateTaskNode_labelStartsUpperCase(final GModelState modelState,
-      final GModelElement element) {
+   private Optional<Marker> validateTaskNode_labelStartsUpperCase(final GModelElement element) {
       TaskNode taskNode = (TaskNode) element;
 
       boolean hasLowerCaseLabel = taskNode.getChildren().stream()
@@ -97,16 +96,14 @@ private static Optional<Marker> validateTaskNode_labelStartsUpperCase(final GMod
       return Optional.empty();
    }
 
-   private static List<Marker> validateDecisionNode(final GModelState modelState,
-      final GModelElement decisionNode) {
+   private List<Marker> validateDecisionNode(final GModelElement decisionNode) {
       List<Marker> markers = new ArrayList<>();
-      validateDecisionNode_hasOneIncomingEdge(modelState, decisionNode).ifPresent(m -> markers.add(m));
+      validateDecisionNode_hasOneIncomingEdge(decisionNode).ifPresent(m -> markers.add(m));
       return markers;
    }
 
    @SuppressWarnings("checkstyle:MethodName")
-   private static Optional<Marker> validateDecisionNode_hasOneIncomingEdge(final GModelState modelState,
-      final GModelElement decisionNode) {
+   private Optional<Marker> validateDecisionNode_hasOneIncomingEdge(final GModelElement decisionNode) {
       Collection<GEdge> incomingEdges = modelState.getIndex().getIncomingEdges(decisionNode);
       if (incomingEdges.size() > 1) {
          return Optional.of(new Marker("Too many incoming edges", "Decision node may only have one incoming edge.",
@@ -118,15 +115,14 @@ private static Optional<Marker> validateDecisionNode_hasOneIncomingEdge(final GM
       return Optional.empty();
    }
 
-   private static List<Marker> validateMergeNode(final GModelState modelState, final GModelElement mergeNode) {
+   private List<Marker> validateMergeNode(final GModelElement mergeNode) {
       List<Marker> markers = new ArrayList<>();
-      validateMergeNode_hasOneOutgoingEdge(modelState, mergeNode).ifPresent(m -> markers.add(m));
+      validateMergeNode_hasOneOutgoingEdge(mergeNode).ifPresent(m -> markers.add(m));
       return markers;
    }
 
    @SuppressWarnings("checkstyle:MethodName")
-   private static Optional<Marker> validateMergeNode_hasOneOutgoingEdge(final GModelState modelState,
-      final GModelElement mergeNode) {
+   private Optional<Marker> validateMergeNode_hasOneOutgoingEdge(final GModelElement mergeNode) {
       Collection<GEdge> outgoingEdges = modelState.getIndex().getOutgoingEdges(mergeNode);
       if (outgoingEdges.size() > 1) {
          return Optional.of(new Marker("Too many outgoing edges", "Merge node may only have one outgoing edge.",

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/core/model/ModelSubmissionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019-2022 EclipseSource and others.
+ * Copyright (c) 2019-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -26,6 +26,10 @@
 import org.eclipse.glsp.server.actions.ActionHandler;
 import org.eclipse.glsp.server.actions.SetDirtyStateAction;
 import org.eclipse.glsp.server.diagram.DiagramConfiguration;
+import org.eclipse.glsp.server.features.validation.Marker;
+import org.eclipse.glsp.server.features.validation.ModelValidator;
+import org.eclipse.glsp.server.features.validation.MarkersReason;
+import org.eclipse.glsp.server.features.validation.SetMarkersAction;
 import org.eclipse.glsp.server.layout.LayoutEngine;
 import org.eclipse.glsp.server.layout.ServerLayoutKind;
 import org.eclipse.glsp.server.model.GModelState;
@@ -48,6 +52,9 @@ public class ModelSubmissionHandler {
    @Inject
    protected GModelState modelState;
 
+   @Inject
+   protected Optional<ModelValidator> validator;
+
    private final Object modelLock = new Object();
 
    /**
@@ -108,6 +115,11 @@ public List<Action> submitModelDirectly(final String reason) {
          if (!diagramConfiguration.needsClientLayout()) {
             result.add(new SetDirtyStateAction(modelState.isDirty(), reason));
          }
+         if (validator.isPresent()) {
+            List<Marker> markers = validator.get() //
+               .validate(Arrays.asList(modelState.getRoot()), MarkersReason.LIVE);
+            result.add(new SetMarkersAction(markers, MarkersReason.LIVE));
+         }
          return result;
       }
    }

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/validation/MarkersReason.java

@@ -0,0 +1,36 @@
+/********************************************************************************
+ * Copyright (c) 2023 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+package org.eclipse.glsp.server.features.validation;
+
+/**
+ * The default reasons for a request for markers.
+ */
+public final class MarkersReason {
+
+   /**
+    * Batch validation executed on demand by the client.
+    */
+   public static final String BATCH = "batch";
+   /**
+    * Live validation executed on start and after model update.
+    */
+   public static final String LIVE = "live";
+
+   private MarkersReason() {
+      // prevent instantiation for class only holding constants.
+   }
+
+}

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/validation/ModelValidator.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019-2021 EclipseSource and others.
+ * Copyright (c) 2019-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -15,6 +15,8 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.features.validation;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.eclipse.glsp.graph.GModelElement;
@@ -23,14 +25,104 @@
  * Validates a list of {@link GModelElement}s based on a set of validation rules and returns corresponding issue
  * {@link Marker}s.
  * An issue marker is a serializable description of the validation violation that can be visualised by the GLSP client.
+ *
+ * There are two default reasons for a validation:
+ * <ol>
+ * <li><i>live</i> validation is executed on open and after each operation. These validation rules should be rather
+ * fast. Overwrite {@link #doLiveValidation(GModelElement)} to implement the live validation rules.</li>
+ * <li><i>batch</i> validation is executed on demand by the client. These validation rules can be more expensive.
+ * Overwrite {@link #doBatchValidation(GModelElement)} to implement the batch validation rules.</li>
+ * </ol>
  */
 public interface ModelValidator {
 
    /**
     * Validates the given list of {@link GModelElement}s and returns a list of {@link Marker}s.
     *
     * @param elements The list of {@link GModelElement} to validate.
+    * @param reason   The reason for a validation request, such as "batch" or "live" validation.
     * @return A list of {@link Marker}s for the validated {@link GModelElement}s.
     */
-   List<Marker> validate(GModelElement... elements);
+   default List<Marker> validate(final List<GModelElement> elements, final String reason) {
+      List<Marker> markers = new ArrayList<>();
+
+      for (GModelElement element : elements) {
+         if (MarkersReason.LIVE.equals(reason)) {
+            markers.addAll(doLiveValidation(element));
+         } else if (MarkersReason.BATCH.equals(reason)) {
+            markers.addAll(doBatchValidation(element));
+         } else {
+            markers.addAll(doValidationForCustomReason(element, reason));
+         }
+         if (!element.getChildren().isEmpty()) {
+            markers.addAll(validate(element.getChildren(), reason));
+         }
+      }
+
+      return markers;
+   }
+
+   /**
+    * Runs a <code>batch</code> validation with the given list of {@link GModelElement}s and returns a list of
+    * {@link Marker}s.
+    *
+    * @param elements The list of {@link GModelElement} to validate.
+    * @return A list of {@link Marker}s for the validated {@link GModelElement}s.
+    */
+   default List<Marker> validate(final GModelElement... elements) {
+      return validate(List.of(elements), MarkersReason.BATCH);
+   }
+
+   /**
+    * Perform the live validation rules for the given <code>element</code>.
+    *
+    * <p>
+    * This will be invoked on start and after each operation for all elements.
+    * Thus, the validation should be rather inexpensive.
+    * There is no need to traverse through the children in this method as {@link #validate(List, String)} will invoke
+    * this method for all children anyway.
+    * </p>
+    *
+    * @param element The element to validate.
+    * @return A list of {@link Marker}s for the validated {@link GModelElement}.
+    */
+   default List<Marker> doLiveValidation(final GModelElement element) {
+      return Collections.emptyList();
+   }
+
+   /**
+    * Perform the batch validation rules for the given <code>element</code>.
+    *
+    * <p>
+    * This will be invoked on demand by the client.
+    * Thus, the validation can include more expensive validation rules.
+    * There is no need to traverse through the children in this method as {@link #validate(List, String)} will invoke
+    * this method for all children anyway.
+    * </p>
+    *
+    * @param element The element to validate.
+    * @return A list of {@link Marker}s for the validated {@link GModelElement}.
+    */
+   default List<Marker> doBatchValidation(final GModelElement element) {
+      return Collections.emptyList();
+   }
+
+   /**
+    * Perform a validation for a custom <code>reason</code> with the given <code>element</code>.
+    *
+    * <p>
+    * GLSP editors may add custom reasons for triggering a validation, other than <code>live</code> and
+    * <code>batch</code>.
+    * Validation requests that are not live or batch validations will be handled by this method.
+    * There is no need to traverse through the children in this method as {@link #validate(List, String)} will invoke
+    * this method for all children anyway.
+    * </p>
+    *
+    * @param element The element to validate.
+    * @return A list of {@link Marker}s for the validated {@link GModelElement}.
+    */
+   default List<Marker> doValidationForCustomReason(final GModelElement element, final String reason) {
+      return Collections.emptyList();
+   }
+
 }

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/validation/RequestMarkersAction.java

@@ -25,18 +25,28 @@ public class RequestMarkersAction extends RequestAction<SetMarkersAction> {
    public static final String KIND = "requestMarkers";
 
    private List<String> elementsIDs;
+   private String reason;
 
    public RequestMarkersAction() {
       this(new ArrayList<>());
    }
 
    public RequestMarkersAction(final List<String> elementsIDs) {
+      this(elementsIDs, MarkersReason.BATCH);
+   }
+
+   public RequestMarkersAction(final List<String> elementsIDs, final String reason) {
       super(KIND);
       this.elementsIDs = elementsIDs;
+      this.reason = reason;
    }
 
    public List<String> getElementsIDs() { return elementsIDs; }
 
    public void setElementsIDs(final List<String> elementsIDs) { this.elementsIDs = elementsIDs; }
 
+   public String getReason() { return reason; }
+
+   public void setReason(final String reason) { this.reason = reason; }
+
 }