Ensure implicit attributes are properly re-calculated

extensions/crossmodel-lang/src/glsp-server/common/cross-model-storage.ts

@@ -7,7 +7,6 @@ import {
    ClientSession,
    ClientSessionListener,
    ClientSessionManager,
-   Disposable,
    DisposableCollection,
    GLSPServerError,
    Logger,
@@ -48,20 +47,31 @@ export class CrossModelStorage implements SourceModelStorage, ClientSessionListe
       // load semantic model from document in language model service
       const sourceUri = this.getSourceUri(action);
       const rootUri = URI.file(sourceUri).toString();
-      await this.state.modelService.open({ uri: rootUri, clientId: this.state.clientId });
-      this.toDispose.push(Disposable.create(() => this.state.modelService.close({ uri: rootUri, clientId: this.state.clientId })));
-      const root = await this.state.modelService.request(rootUri, isCrossModelRoot);
-      this.state.setSemanticRoot(rootUri, root);
+      const root = await this.update(rootUri);
+      if (!root) {
+         return;
+      }
+      this.toDispose.push(await this.state.modelService.open({ uri: rootUri, clientId: this.state.clientId }));
       this.toDispose.push(
          this.state.modelService.onUpdate<CrossModelRoot>(rootUri, async event => {
             if (this.state.clientId !== event.sourceClientId || event.reason !== 'changed') {
-               this.state.setSemanticRoot(rootUri, event.model);
+               await this.update(rootUri, event.model);
                this.actionDispatcher.dispatchAll(await this.submissionHandler.submitModel('external'));
             }
          })
       );
    }
 
+   protected async update(uri: string, root?: CrossModelRoot): Promise<CrossModelRoot | undefined> {
+      const newRoot = root ?? (await this.state.modelService.request(uri, isCrossModelRoot));
+      if (newRoot) {
+         this.state.setSemanticRoot(uri, newRoot);
+      } else {
+         this.logger.error('Could not find model for ' + uri);
+      }
+      return newRoot;
+   }
+
    saveSourceModel(action: SaveModelAction): MaybePromise<void> {
       const saveUri = this.getFileUri(action);
 

extensions/crossmodel-lang/src/language-server/cross-model-module.ts

@@ -40,6 +40,7 @@ import { CrossModelGeneratedModule, CrossModelGeneratedSharedModule } from './ge
 import { createCrossModelCompletionParser } from './lexer/cross-model-completion-parser.js';
 import { CrossModelLexer } from './lexer/cross-model-lexer.js';
 import { CrossModelTokenBuilder } from './lexer/cross-model-token-generator.js';
+import { CrossModelLinker } from './references/cross-model-linker.js';
 
 /***************************
  * Shared Module
@@ -128,6 +129,7 @@ export interface CrossModelModuleContext {
 export interface CrossModelAddedServices {
    references: {
       IdProvider: DefaultIdProvider;
+      Linker: CrossModelLinker;
    };
    validation: {
       CrossModelValidator: CrossModelValidator;
@@ -158,7 +160,8 @@ export function createCrossModelModule(
          ScopeComputation: services => new CrossModelScopeComputation(services),
          ScopeProvider: services => new CrossModelScopeProvider(services),
          IdProvider: services => new DefaultIdProvider(services),
-         NameProvider: services => services.references.IdProvider
+         NameProvider: services => services.references.IdProvider,
+         Linker: services => new CrossModelLinker(services)
       },
       validation: {
          CrossModelValidator: services => new CrossModelValidator(services)

extensions/crossmodel-lang/src/language-server/references/cross-model-linker.ts

@@ -0,0 +1,17 @@
+/********************************************************************************
+ * Copyright (c) 2024 CrossBreeze.
+ ********************************************************************************/
+
+import { AstNode, DefaultLinker, DocumentState, LangiumDocument } from 'langium';
+import { isMapping, isSystemDiagram } from '../generated/ast.js';
+import { hasSemanticRoot } from '../util/ast-util.js';
+
+export class CrossModelLinker extends DefaultLinker {
+   override unlink(document: LangiumDocument<AstNode>): void {
+      super.unlink(document);
+      if (hasSemanticRoot(document, isMapping) || hasSemanticRoot(document, isSystemDiagram)) {
+         // we want to re-compute the implicit attributes for our nodes
+         document.state = Math.min(document.state, DocumentState.IndexedContent);
+      }
+   }
+}

extensions/crossmodel-lang/src/language-server/util/ast-util.ts

@@ -174,10 +174,11 @@ export function createAttributeMappingTarget(container: AttributeMapping, target
 /**
  * Retrieve the document in which the given AST node is contained. A reference to the document is
  * usually held by the root node of the AST.
- *
- * @throws an error if the node is not contained in a document.
  */
-export function findDocument<T extends AstNode = AstNode>(node: AstNode): LangiumDocument<T> | undefined {
+export function findDocument<T extends AstNode = AstNode>(node?: AstNode): LangiumDocument<T> | undefined {
+   if (!node) {
+      return undefined;
+   }
    const rootNode = findRootNode(node);
    const result = rootNode.$document;
    return result ? <LangiumDocument<T>>result : undefined;
@@ -198,3 +199,7 @@ export function findSemanticRoot(document: LangiumDocument<CrossModelRoot>): Ent
    const root = document.parseResult.value;
    return root.entity ?? root.mapping ?? root.relationship ?? root.systemDiagram;
 }
+
+export function hasSemanticRoot<T>(document: LangiumDocument<any>, guard: (item: unknown) => item is T): boolean {
+   return guard(findSemanticRoot(document));
+}

extensions/crossmodel-lang/src/model-server/model-service.ts

@@ -61,7 +61,7 @@ export class ModelService {
     *
     * @param uri document URI
     */
-   async open(args: OpenModelArgs): Promise<void> {
+   async open(args: OpenModelArgs): Promise<Disposable> {
       return this.documentManager.open(args);
    }
 

extensions/crossmodel-lang/src/model-server/open-text-document-manager.ts

@@ -81,7 +81,8 @@ export class OpenTextDocumentManager {
       return this.documentBuilder.onBuildPhase(DocumentState.Validated, (allChangedDocuments, _token) => {
          const changedDocument = allChangedDocuments.find(document => document.uri.toString() === uri);
          if (changedDocument) {
-            const sourceClientId = this.getSourceClientId(changedDocument, allChangedDocuments);
+            const buildTrigger = allChangedDocuments.find(document => document.uri.toString() === this.lastUpdate?.changed?.[0].toString());
+            const sourceClientId = this.getSourceClientId(buildTrigger ?? changedDocument, allChangedDocuments);
             const event: ModelUpdatedEvent<T> = {
                model: changedDocument.parseResult.value as T,
                sourceClientId,
@@ -109,12 +110,13 @@ export class OpenTextDocumentManager {
       );
    }
 
-   async open(args: OpenModelArgs): Promise<void> {
+   async open(args: OpenModelArgs): Promise<Disposable> {
       // only create a dummy document if it is already open as we use the synced state anyway
       const textDocument = this.isOpen(args.uri)
          ? this.createDummyDocument(args.uri)
          : await this.createDocumentFromFileSystem(args.uri, args.languageId);
       this.textDocuments.notifyDidOpenTextDocument({ textDocument }, args.clientId);
+      return Disposable.create(() => this.close(args));
    }
 
    async close(args: CloseModelArgs): Promise<void> {

extensions/crossmodel-lang/src/model-server/openable-text-documents.ts

@@ -232,8 +232,10 @@ export class OpenableTextDocuments<T extends TextDocument> extends TextDocuments
       }
    }
 
-   getChangeSource(uri: string, version: number): string | undefined {
-      return this.__changeHistory.get(uri)?.[version];
+   getChangeSource(uri: string, version?: number): string | undefined {
+      const history = this.__changeHistory.get(uri);
+      // given version or last entry
+      return version ? history?.[version] : history?.at(-1);
    }
 
    isOpen(uri: string): boolean {