Extended workflow example by injecting non-default

examples/workflow-server/src/common/workflow-diagram-module.ts

@@ -23,8 +23,10 @@ import {
     EdgeCreationChecker,
     GLSPServer,
     GModelDiagramModule,
+    GModelFactory,
     InstanceMultiBinding,
     LabelEditValidator,
+    ModelState,
     ModelValidator,
     MultiBinding,
     NavigationTargetProvider,
@@ -59,6 +61,8 @@ import { WorkflowDiagramConfiguration } from './workflow-diagram-configuration';
 import { WorkflowEdgeCreationChecker } from './workflow-edge-creation-checker';
 import { WorkflowGLSPServer } from './workflow-glsp-server';
 import { WorkflowPopupFactory } from './workflow-popup-factory';
+import { WorkflowModelFactory } from './workflow-gmodel-factory';
+import { WorkflowModelState } from './workflow-model-state';
 
 @injectable()
 export class WorkflowServerModule extends ServerModule {
@@ -91,6 +95,14 @@ export class WorkflowDiagramModule extends GModelDiagramModule {
         binding.add(EditTaskOperationHandler);
     }
 
+    protected override bindModelState(): BindingTarget<ModelState> {
+        return { service: WorkflowModelState };
+    }
+
+    protected override bindGModelFactory(): BindingTarget<GModelFactory> {
+        return WorkflowModelFactory;
+    }
+
     protected bindDiagramConfiguration(): BindingTarget<DiagramConfiguration> {
         return WorkflowDiagramConfiguration;
     }

examples/workflow-server/src/common/workflow-gmodel-factory.ts

@@ -0,0 +1,50 @@
+/********************************************************************************
+ * 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
+ * http://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
+ ********************************************************************************/
+import { GModelFactory, GModelSerializer } from '@eclipse-glsp/server';
+import { inject, injectable } from 'inversify';
+import { WorkflowModelState } from './workflow-model-state';
+
+/**
+ * This class provides the method to transform a source model into a GModel, updating the {@link GModelRoot}.
+ *
+ * This is, however, only relevant in cases where the source model is not already a valid GModel.
+ *
+ * Here, this custom implementation only serves to provide an entrypoint, but for a more extensive example
+ * look to {@link https://eclipse.dev/glsp/documentation/gmodel/#graphical-model-factory}.
+ */
+@injectable()
+export class WorkflowModelFactory implements GModelFactory {
+    @inject(GModelSerializer)
+    protected modelSerializer: GModelSerializer;
+
+    @inject(WorkflowModelState)
+    protected modelState: WorkflowModelState;
+
+    /**
+     * Since this is an example using Workflow, which inherently already uses a GModel format, no difference
+     * exists between the underlying source model and `root`. Therefore all handlers directly update the
+     * root, making this method detrimental after first model creation.
+     *
+     * If other handlers are instead written to update `modelState.model`, then the root has to be updated
+     * after every change.
+     */
+    createModel(): void {
+        if (!this.modelState.root) {
+            const root = this.modelSerializer.createRoot(this.modelState.model);
+            this.modelState.updateRoot(root);
+        }
+    }
+}

examples/workflow-server/src/common/workflow-model-state.ts

@@ -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
+ * http://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
+ ********************************************************************************/
+import { DefaultModelState, GModelElementSchema } from '@eclipse-glsp/server';
+import { injectable } from 'inversify';
+
+/**
+ * This model state serves to demonstrate how to extend or create a custom model state.
+ *
+ * While this may not be necessary when handling JSON formatted graphs that already
+ * correspond to a GModel (as the Workflow example does), since {@link DefaultModelState}
+ * is sufficient, it nonetheless provides an adequte example for custom formats.
+ */
+@injectable()
+export class WorkflowModelState extends DefaultModelState {
+    /**
+     * The source model that needs to be transformed into a GModel and its {@link GModelRoot}.
+     * It is saved in the {@link ModelState} in order to later be available in the
+     * corresponding {@link GModelFactory}.
+     *
+     * Its type solely depends on the used source model.
+     */
+    model: GModelElementSchema;
+}

examples/workflow-server/src/common/workflow-model-storage.ts

@@ -0,0 +1,66 @@
+/********************************************************************************
+ * 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
+ * http://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
+ ********************************************************************************/
+import {
+    GModelElementSchema,
+    GModelSerializer,
+    MaybePromise,
+    RequestModelAction,
+    SaveModelAction,
+    SourceModelStorage
+} from '@eclipse-glsp/server';
+import * as fs from 'fs';
+import { inject, injectable } from 'inversify';
+import * as os from 'os';
+import { WorkflowModelState } from './workflow-model-state';
+
+/**
+ * This {@link SourceModelStorage} serves as a naive implementation similar to the default {@link GModelStorage}.
+ * The main difference being that the source model is not directly instantiated as GModel, which works
+ * in the Workflow example (since its data format is already a valid GModel), but not generally. Therefore,
+ * this example is more easily applicable to custom model formats.
+ *
+ * The model saved here is later on transformed in {@link WorkflowModelFactory} and has to be updated in the handlers,
+ * if source model and GModel are different.
+ */
+@injectable()
+export class WorkflowSourceModelStorage implements SourceModelStorage {
+    @inject(GModelSerializer)
+    protected modelSerializer: GModelSerializer;
+
+    @inject(WorkflowModelState)
+    protected modelState: WorkflowModelState;
+
+    loadSourceModel(action: RequestModelAction): MaybePromise<void> {
+        const sourceUri = action.options!['sourceUri'] as string;
+        const model = this.loadJsonFile(sourceUri);
+        this.modelState.model = model;
+        this.modelState.set('sourceUri', sourceUri);
+    }
+
+    saveSourceModel(action: SaveModelAction): MaybePromise<void> {
+        const fileUri = this.modelState.get('sourceUri') as string;
+        const schema = this.modelSerializer.createSchema(this.modelState.root);
+        fs.writeFileSync(fileUri, JSON.stringify(schema));
+    }
+
+    protected loadJsonFile(path: string): GModelElementSchema {
+        if (os.platform() === 'win32') {
+            path = path.replace(/^\//, '');
+        }
+        const data = fs.readFileSync(path, { encoding: 'utf8' });
+        return JSON.parse(data);
+    }
+}

examples/workflow-server/src/node/app.ts

@@ -16,20 +16,24 @@
 import 'reflect-metadata';
 
 import { configureELKLayoutModule } from '@eclipse-glsp/layout-elk';
-import { createAppModule, GModelStorage, SocketServerLauncher, WebSocketServerLauncher } from '@eclipse-glsp/server/node';
+import { createAppModule, SocketServerLauncher, WebSocketServerLauncher } from '@eclipse-glsp/server/node';
 import { Container } from 'inversify';
 
 import { WorkflowLayoutConfigurator } from '../common/layout/workflow-layout-configurator';
 import { WorkflowDiagramModule, WorkflowServerModule } from '../common/workflow-diagram-module';
 import { createWorkflowCliParser } from './workflow-cli-parser';
+import { WorkflowSourceModelStorage } from '../common/workflow-model-storage';
 
 async function launch(argv?: string[]): Promise<void> {
     const options = createWorkflowCliParser().parse(argv);
     const appContainer = new Container();
     appContainer.load(createAppModule(options));
 
     const elkLayoutModule = configureELKLayoutModule({ algorithms: ['layered'], layoutConfigurator: WorkflowLayoutConfigurator });
-    const serverModule = new WorkflowServerModule().configureDiagramModule(new WorkflowDiagramModule(() => GModelStorage), elkLayoutModule);
+    const serverModule = new WorkflowServerModule().configureDiagramModule(
+        new WorkflowDiagramModule(() => WorkflowSourceModelStorage),
+        elkLayoutModule
+    );
 
     if (options.webSocket) {
         const launcher = appContainer.resolve(WebSocketServerLauncher);