Introduce DocumentUpdateHandler service

examples/arithmetics/src/extension.ts

@@ -5,7 +5,7 @@
  ******************************************************************************/
 
 import type { LanguageClientOptions, ServerOptions } from 'vscode-languageclient/node.js';
-import * as vscode from 'vscode';
+import type * as vscode from 'vscode';
 import * as path from 'node:path';
 import { LanguageClient, TransportKind } from 'vscode-languageclient/node.js';
 
@@ -37,16 +37,9 @@ function startLanguageClient(context: vscode.ExtensionContext): LanguageClient {
         debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.calc');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
-        documentSelector: [{ scheme: 'file', language: 'arithmetics' }],
-        synchronize: {
-            // Notify the server about file changes to files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+        documentSelector: [{ scheme: 'file', language: 'arithmetics' }]
     };
 
     // Create the language client and start the client.

examples/domainmodel/src/extension.ts

@@ -5,7 +5,7 @@
  ******************************************************************************/
 
 import type { LanguageClientOptions, ServerOptions } from 'vscode-languageclient/node.js';
-import * as vscode from 'vscode';
+import type * as vscode from 'vscode';
 import * as path from 'node:path';
 import { LanguageClient, TransportKind } from 'vscode-languageclient/node.js';
 
@@ -37,16 +37,9 @@ function startLanguageClient(context: vscode.ExtensionContext): LanguageClient {
         debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.dmodel');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
-        documentSelector: [{ scheme: 'file', language: 'domain-model' }],
-        synchronize: {
-            // Notify the server about file changes to files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+        documentSelector: [{ scheme: 'file', language: 'domain-model' }]
     };
 
     // Create the language client and start the client.

examples/requirements/src/extension.ts

@@ -6,7 +6,7 @@
 
 import type { LanguageClientOptions, ServerOptions } from 'vscode-languageclient/node.js';
 import { LanguageClient, TransportKind } from 'vscode-languageclient/node.js';
-import * as vscode from 'vscode';
+import type * as vscode from 'vscode';
 import * as path from 'node:path';
 
 let client: LanguageClient;
@@ -38,18 +38,11 @@ function startLanguageClient(context: vscode.ExtensionContext): LanguageClient {
         debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.(req|tst)');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
         documentSelector: [
             { scheme: 'file', language: 'tests-lang' },
-            { scheme: 'file', language: 'requirements-lang' }],
-        synchronize: {
-            // Notify the server about file changes to files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+            { scheme: 'file', language: 'requirements-lang' }]
     };
 
     // Create the language client and start the client.

examples/statemachine/src/extension.ts

@@ -5,7 +5,7 @@
  ******************************************************************************/
 
 import type { LanguageClientOptions, ServerOptions } from 'vscode-languageclient/node.js';
-import * as vscode from 'vscode';
+import type * as vscode from 'vscode';
 import * as path from 'node:path';
 import { LanguageClient, TransportKind } from 'vscode-languageclient/node.js';
 
@@ -37,16 +37,9 @@ function startLanguageClient(context: vscode.ExtensionContext): LanguageClient {
         debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.statemachine');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
-        documentSelector: [{ scheme: 'file', language: 'statemachine' }],
-        synchronize: {
-            // Notify the server about file changes to files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+        documentSelector: [{ scheme: 'file', language: 'statemachine' }]
     };
 
     // Create the language client and start the client.

packages/generator-langium/templates/vscode/src/extension/main.ts

@@ -1,5 +1,5 @@
 import type { LanguageClientOptions, ServerOptions} from 'vscode-languageclient/node.js';
-import * as vscode from 'vscode';
+import type * as vscode from 'vscode';
 import * as path from 'node:path';
 import { LanguageClient, TransportKind } from 'vscode-languageclient/node.js';
 
@@ -32,16 +32,9 @@ function startLanguageClient(context: vscode.ExtensionContext): LanguageClient {
         debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.<%= file-glob-extension %>');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
-        documentSelector: [{ scheme: 'file', language: '<%= language-id %>' }],
-        synchronize: {
-            // Notify the server about file changes to files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+        documentSelector: [{ scheme: 'file', language: '<%= language-id %>' }]
     };
 
     // Create the language client and start the client.

packages/langium-vscode/src/extension.ts

@@ -45,17 +45,10 @@ async function startLanguageClient(context: vscode.ExtensionContext): Promise<La
         }
     };
 
-    const fileSystemWatcher = vscode.workspace.createFileSystemWatcher('**/*.langium');
-    context.subscriptions.push(fileSystemWatcher);
-
     // Options to control the language client
     const clientOptions: LanguageClientOptions = {
         // Register the server for langium documents
-        documentSelector: [{ scheme: 'file', language: 'langium' }],
-        synchronize: {
-            // Notify the server about file changes to langium files contained in the workspace
-            fileEvents: fileSystemWatcher
-        }
+        documentSelector: [{ scheme: 'file', language: 'langium' }]
     };
 
     // Create the language client and start the client.

packages/langium/src/default-module.ts

@@ -15,6 +15,7 @@ import { createCompletionParser } from './parser/completion-parser-builder.js';
 import { DefaultCompletionProvider } from './lsp/completion/completion-provider.js';
 import { DefaultDocumentHighlightProvider } from './lsp/document-highlight-provider.js';
 import { DefaultDocumentSymbolProvider } from './lsp/document-symbol-provider.js';
+import { DefaultDocumentUpdateHandler } from './lsp/document-update-handler.js';
 import { DefaultFoldingRangeProvider } from './lsp/folding-range-provider.js';
 import { DefaultFuzzyMatcher } from './lsp/fuzzy-matcher.js';
 import { DefaultDefinitionProvider } from './lsp/definition-provider.js';
@@ -136,6 +137,7 @@ export function createDefaultSharedModule(context: DefaultSharedModuleContext):
         lsp: {
             Connection: () => context.connection,
             LanguageServer: (services) => new DefaultLanguageServer(services),
+            DocumentUpdateHandler: (services) => new DefaultDocumentUpdateHandler(services),
             WorkspaceSymbolProvider: (services) => new DefaultWorkspaceSymbolProvider(services),
             NodeKindProvider: () => new DefaultNodeKindProvider(),
             FuzzyMatcher: () => new DefaultFuzzyMatcher()

packages/langium/src/lsp/document-update-handler.ts

@@ -0,0 +1,95 @@
+/******************************************************************************
+ * Copyright 2023 TypeFox GmbH
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License, which is available in the project root.
+ ******************************************************************************/
+
+import type { DidChangeWatchedFilesParams, DidChangeWatchedFilesRegistrationOptions, TextDocumentChangeEvent } from 'vscode-languageserver';
+import type { TextDocument } from 'vscode-languageserver-textdocument';
+import type { LangiumSharedServices } from '../services.js';
+import type { MutexLock } from '../utils/promise-util.js';
+import type { DocumentBuilder } from '../workspace/document-builder.js';
+import { DidChangeWatchedFilesNotification, FileChangeType } from 'vscode-languageserver';
+import { URI } from 'vscode-uri';
+import { stream } from '../utils/stream.js';
+
+/**
+ * Shared service for handling text document changes and watching relevant files.
+ */
+export interface DocumentUpdateHandler {
+
+    /**
+     * A content change event was triggered by the `TextDocuments` service.
+     */
+    didChangeContent(change: TextDocumentChangeEvent<TextDocument>): void;
+
+    /**
+     * The client detected changes to files and folders watched by the language client.
+     */
+    didChangeWatchedFiles(params: DidChangeWatchedFilesParams): void;
+
+}
+
+export class DefaultDocumentUpdateHandler implements DocumentUpdateHandler {
+
+    protected readonly documentBuilder: DocumentBuilder;
+    protected readonly mutexLock: MutexLock;
+
+    constructor(services: LangiumSharedServices) {
+        this.documentBuilder = services.workspace.DocumentBuilder;
+        this.mutexLock = services.workspace.MutexLock;
+
+        let canRegisterFileWatcher = false;
+        services.lsp.LanguageServer.onInitialize(params => {
+            canRegisterFileWatcher = Boolean(params.capabilities.workspace?.didChangeWatchedFiles?.dynamicRegistration);
+        });
+
+        services.lsp.LanguageServer.onInitialized(_params => {
+            if (canRegisterFileWatcher) {
+                this.registerFileWatcher(services);
+            }
+        });
+    }
+
+    protected registerFileWatcher(services: LangiumSharedServices): void {
+        const fileExtensions = stream(services.ServiceRegistry.all)
+            .flatMap(language => language.LanguageMetaData.fileExtensions)
+            .map(ext => ext.startsWith('.') ? ext.substring(1) : ext)
+            .distinct()
+            .toArray();
+        if (fileExtensions.length > 0) {
+            const connection = services.lsp.Connection;
+            const options: DidChangeWatchedFilesRegistrationOptions = {
+                watchers: [{
+                    globPattern: fileExtensions.length === 1
+                        ? `**/*.${fileExtensions[0]}`
+                        : `**/*.{${fileExtensions.join(',')}}`
+                }]
+            };
+            connection?.client.register(DidChangeWatchedFilesNotification.type, options);
+        }
+    }
+
+    protected fireDocumentUpdate(changed: URI[], deleted: URI[]): void {
+        this.mutexLock.lock(token => this.documentBuilder.update(changed, deleted, token));
+    }
+
+    didChangeContent(change: TextDocumentChangeEvent<TextDocument>): void {
+        this.fireDocumentUpdate([URI.parse(change.document.uri)], []);
+    }
+
+    didChangeWatchedFiles(params: DidChangeWatchedFilesParams): void {
+        const changedUris = stream(params.changes)
+            .filter(c => c.type !== FileChangeType.Deleted)
+            .distinct(c => c.uri)
+            .map(c => URI.parse(c.uri))
+            .toArray();
+        const deletedUris = stream(params.changes)
+            .filter(c => c.type === FileChangeType.Deleted)
+            .distinct(c => c.uri)
+            .map(c => URI.parse(c.uri))
+            .toArray();
+        this.fireDocumentUpdate(changedUris, deletedUris);
+    }
+
+}

packages/langium/src/lsp/file-operation-handler.ts

@@ -0,0 +1,63 @@
+/******************************************************************************
+ * Copyright 2023 TypeFox GmbH
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License, which is available in the project root.
+ ******************************************************************************/
+
+import type { CreateFilesParams, DeleteFilesParams, FileOperationOptions, RenameFilesParams, WorkspaceEdit } from 'vscode-languageserver';
+import type { MaybePromise } from '../utils/promise-util.js';
+
+/**
+ * Shared service for handling file changes such as file creation, deletion and renaming.
+ * The interface methods are optional, so they are only registered if they are implemented.
+ */
+export interface FileOperationHandler {
+
+    /**
+     * These options are reported to the client as part of the ServerCapabilities.
+     */
+    readonly fileOperationOptions: FileOperationOptions;
+
+    /**
+     * Files were created from within the client.
+     * This notification must be registered with the {@link fileOperationOptions}.
+     */
+    didCreateFiles?(params: CreateFilesParams): void;
+
+    /**
+     * Files were renamed from within the client.
+     * This notification must be registered with the {@link fileOperationOptions}.
+     */
+    didRenameFiles?(params: RenameFilesParams): void;
+
+    /**
+     * Files were deleted from within the client.
+     * This notification must be registered with the {@link fileOperationOptions}.
+     */
+    didDeleteFiles?(params: DeleteFilesParams): void;
+
+    /**
+     * Called before files are actually created as long as the creation is triggered from within
+     * the client either by a user action or by applying a workspace edit.
+     * This request must be registered with the {@link fileOperationOptions}.
+     * @returns a WorkspaceEdit which will be applied to workspace before the files are created.
+     */
+    willCreateFiles?(params: CreateFilesParams): MaybePromise<WorkspaceEdit | null>;
+
+    /**
+     * Called before files are actually renamed as long as the rename is triggered from within
+     * the client either by a user action or by applying a workspace edit.
+     * This request must be registered with the {@link fileOperationOptions}.
+     * @returns a WorkspaceEdit which will be applied to workspace before the files are renamed.
+     */
+    willRenameFiles?(params: RenameFilesParams): MaybePromise<WorkspaceEdit | null>;
+
+    /**
+     * Called before files are actually deleted as long as the deletion is triggered from within
+     * the client either by a user action or by applying a workspace edit.
+     * This request must be registered with the {@link fileOperationOptions}.
+     * @returns a WorkspaceEdit which will be applied to workspace before the files are deleted.
+     */
+    willDeleteFiles?(params: DeleteFilesParams): MaybePromise<WorkspaceEdit | null>;
+
+}