@eclipse-glsp/vscode-integration

Eclipse GLSP VSCode Integration

This package contains the glue code for integrating GLSP diagrams in VS Code. This library enables the implementation of GLSP Diagram editors for VS Code base on the Custom Editor API.

Where to find the sources?

In addition to this repository, the related source code can be found here:

• https://github.com/eclipse-glsp/glsp-server
• https://github.com/eclipse-glsp/glsp-client

Getting started

This section will show you how to get your first GLSP extension up and running using the GLSP VSCode Integration.

Example Extension

You can find a complete example extension that uses this package here. It makes heavy use of default implementations like the default GLSP server, the default GLSP client and the default GLSP Sprotty client.

Example Code

There are a few steps that are absolutely necessary for the GLSP VSCode Integration to work. They are outlined in this section.

Extension

First you need to set up your extension starter code. This is done by setting the "main" field of your package.json to the entry point of your extension and exporting an activate() function from that file. For more information on how to set up your VSCode extension please visit https://code.visualstudio.com/api.

Code Example

import * as vscode from 'vscode';

export async function activate(context: vscode.ExtensionContext): Promise<void> {
    // Your extension code here.
}

Server

Next we will start a GLSP server from within the activate function. If you have already have the server running through some other process you can skip this step.

If you are using the default GLSP server implementation provided at https://github.com/eclipse-glsp/glsp-server, you can use the GlspServerLauncher quickstart component to start the server with very little code:

Code Example

import { GlspServerLauncher } from '@eclipse-glsp/vscode-integration/lib/quickstart-components';

export async function activate(context: vscode.ExtensionContext): Promise<void> {
    const serverProcess = new GlspServerLauncher({
        jarPath: '/your/path/to/server.jar',
        serverPort: 5007
    });
    context.subscriptions.push(serverProcess);
    await serverProcess.start();
}

Server Interface and GLSP VSCode Connector

A connector class is needed to provide an interface for the _GLSP VSCode integration_to communicate with the server. If you are using the default GLSP server which communicates over JSON-RPC, you can make use of the SocketGlspVscodeServer quickstart component to implement the needed interface with very little boilerplate code.

If we have a server component providing the needed interface we can create an instance of the GlspVscodeConnector and pass the server component. The GlspVscodeConnector lies at the core of this package and provides all the needed functionality.

Code Example

import { GlspVscodeConnector } from '@eclipse-glsp/vscode-integration';
import { SocketGlspVscodeServer } from '@eclipse-glsp/vscode-integration/lib/quickstart-components';

export async function activate(context: vscode.ExtensionContext): Promise<void> {
    // (Server startup code from above here...)

    const workflowServer = new SocketGlspVscodeServer({
        clientId: 'some.client.id',
        clientName: 'SomeClientName',
        serverPort: 5007
    });

    const glspVscodeConnector = new GlspVscodeConnector({ server: workflowServer });

    context.subscriptions.push(workflowServer, glspVscodeConnector);
}

Custom Editor Provider

In order to have a custom editor in VSCode a component implementing the vscode.CustomEditorProvider needs to be registered from within the extension (more information on custom editors here).

The GLSP VSCode integration package gives you free reign over how you implement your CustomEditorProvider, however a few function calls at certain places are needed for the integration to work properly:

• The onDidChangeCustomDocument of your CustomEditorProvider should always fire at least when GlspVscodeConnector.onDidChangeCustomDocument fires.
• GlspVscodeConnector.saveDocument(document) should be called when CustomEditorProvider.saveCustomDocument is called.
• GlspVscodeConnector.saveDocument(document, destination) should be called when CustomEditorProvider.saveCustomDocumentAs is called.
• GlspVscodeConnector.revertDocument() should be called when CustomEditorProvider.revertCustomDocument is called.

You can use the GlspEditorProvider quickstart component to set up such an editor provider without much boilerplate code.

If you chose to create a CustomEditorProvider yourself, the resolveCustomEditor function of the CustomEditorProvider act as an excellent place to register your GLSP clients. You can do this with the GlspVscodeConnector.registerClient(client)function. You are free to choose on how your clients implement the needed interface,however if you need inspiration on how to do it with the default GLSP components, you can take a look at the example here.

Code Example

import MyCustomEditorProvider from './my-custom-editor-provider.ts';

export async function activate(context: vscode.ExtensionContext): Promise<void> {
    // (Server startup code from above here...)
    // (GlspVscodeConnector code from above here...)

    const customEditorProvider = vscode.window.registerCustomEditorProvider(
        'your.custom.editor',
        new MyCustomEditorProvider(glspVscodeConnector),
        {
            webviewOptions: { retainContextWhenHidden: true },
            supportsMultipleEditorsPerDocument: false
        }
    );

    context.subscriptions.push(customEditorProvider);
}

// my-custom-editor-provider.ts
export default class WorkflowEditorProvider implements vscode.CustomEditorProvider {
    onDidChangeCustomDocument: vscode.Event<vscode.CustomDocumentContentChangeEvent<vscode.CustomDocument>>;

    constructor(private readonly glspVscodeConnector: GlspVscodeConnector) {
        this.onDidChangeCustomDocument = glspVscodeConnector.onDidChangeCustomDocument; // necessary
    }

    // (Any other methods needed for the vscode.CustomEditorProvider interface here.)

    saveCustomDocument(document: vscode.CustomDocument, cancellation: vscode.CancellationToken): Thenable<void> {
        return this.glspVscodeConnector.saveDocument(document); // necessary
    }

    saveCustomDocumentAs(document: vscode.CustomDocument, destination: vscode.Uri, cancellation: vscode.CancellationToken): Thenable<void> {
        return this.glspVscodeConnector.saveDocument(document, destination); // necessary
    }

    revertCustomDocument(document: vscode.CustomDocument, cancellation: vscode.CancellationToken): Thenable<void> {
        return this.glspVscodeConnector.revertDocument(document, 'your.diagram.type'); // necessary
    }

    resolveCustomEditor(
        document: vscode.CustomDocument,
        webviewPanel: vscode.WebviewPanel,
        token: vscode.CancellationToken
    ): void | Thenable<void> {
        const onSendToClientEmitter = new vscode.EventEmitter<unknown>();
        const onClientMessage = new vscode.EventEmitter<unknown>();

        // (Your code to send event content to webview here using onSendToClientEmitter.)
        // (Your code to emit messages from client with onClientSendEmitter.)

        this.glspVscodeConnector.registerClient({
            clientId: 'your.glsp.client.id.here', // Should be different each time resolve custom Editor is called - must be equal to the ids the client will send in its messages
            document: document,
            webviewPanel: webviewPanel,
            onClientMessage: onClientSendEmitter.event,
            onSendToClientEmitter: onSendToClientEmitter
        });

        webviewPanel.webview.html = `(Your webview HTML here)`;
    }
}

Final touches

All that's left to do is a final call to start the server and the extension should be up and running.

Code Example

export async function activate(context: vscode.ExtensionContext): Promise<void> {
    // (Server startup code from above here...)
    // (GlspVscodeConnector code from above here...)
    // (CustomEditorProvider code from above here...)

    workflowServer.start();
}

API

This package exports a number of members, the most important one being the GlspVscodeConnector-Class.

GlspVscodeConnector

This is the core of the VSCode integration and provides various functionality. It primarily intercepts certain GLSP Actions sent from the clients or server to trigger VSCode specific contributions. This currently includes:

• File dirty state
• File "Save" and "Save as..."
• File reverting
• Diagnostics or "markers" and "validations"
• External target navigation
• Exporting as SVG (with dialog window)
• Providing element selection context to extensions

Options

The GlspVscodeConnector takes one constructor argument - an object containing its configuration.

export interface GlspVscodeConnectorOptions {
    /**
     * The GLSP server (or its wrapper) that the VSCode integration should use.
     */
    server: GlspVscodeServer;

    /**
     * Wether the GLSP-VSCode integration should log various events. This is useful
     * if you want to find out what events the VSCode integration is receiving from
     * and sending to the server and clients.
     *
     * Defaults to `false`.
     */
    logging?: boolean;

    /**
     * Optional property to intercept (and/or modify) messages sent from the client
     * to the VSCode integration via `GlspVscodeClient.onClientSend`.
     *
     * @param message Contains the original message sent by the client.
     * @param callback A callback to control how messages are handled further.
     */
    onBeforeReceiveMessageFromClient?: (message: unknown, callback: InterceptorCallback) => void;

    /**
     * Optional property to intercept (and/or modify) messages sent from the server
     * to the VSCode integration via `GlspVscodeServer.onServerSend`.
     *
     * @param message Contains the original message sent by the client.
     * @param callback A callback to control how messages are handled further.
     */
    onBeforeReceiveMessageFromServer?(message: unknown, callback: InterceptorCallback): void;

    /**
     * Optional property to intercept (and/or modify) messages sent from the VSCode
     * integration to the server via the `GlspVscodeServer.onServerReceiveEmitter`.
     *
     * The returned value from this function is the message that will be propagated
     * to the server. It can be modified to anything. Returning `undefined` will
     * cancel the propagation.
     *
     * @param originalMessage The original message received by the VSCode integration
     * from the client.
     * @param processedMessage If the VSCode integration modified the received message
     * in any way, this parameter will contain the modified message. If the VSCode
     * integration did not modify the message, this parameter will be identical to
     * `originalMessage`.
     * @param messageChanged This parameter will indicate wether the VSCode integration
     * modified the incoming message. In other words: Whether `originalMessage`
     * and `processedMessage` are different.
     * @returns A message that will be propagated to the server. If the message
     * is `undefined` the propagation will be cancelled.
     */
    onBeforePropagateMessageToServer?(originalMessage: unknown, processedMessage: unknown, messageChanged: boolean): unknown | undefined;

    /**
     * Optional property to intercept (and/or modify) messages sent from the VSCode
     * integration to a client via the `GlspVscodeClient.onClientReceiveEmitter`.
     *
     * The returned value from this function is the message that will be propagated
     * to the client. It can be modified to anything. Returning `undefined` will
     * cancel the propagation.
     *
     * @param originalMessage The original message received by the VSCode integration
     * from the server.
     * @param processedMessage If the VSCode integration modified the received message
     * in any way, this parameter will contain the modified message. If the VSCode
     * integration did not modify the message, this parameter will be identical to
     * `originalMessage`.
     * @param messageChanged This parameter will indicate wether the VSCode integration
     * modified the incoming message. In other words: Whether `originalMessage`
     * and `processedMessage` are different.
     * @returns A message that will be propagated to the client. If the message
     * is `undefined` the propagation will be cancelled.
     */
    onBeforePropagateMessageToClient?(originalMessage: unknown, processedMessage: unknown, messageChanged: boolean): unknown | undefined;
}

Methods and Fields

interface GlspVscodeConnector<D extends vscode.CustomDocument = vscode.CustomDocument> extends vscode.Disposable {
    /**
     * A subscribable event which fires with an array containing the IDs of all
     * selected elements when the selection of the editor changes.
     */
    onSelectionUpdate: vscode.Event<string[]>;

    /**
     * A subscribable event which fires when a document changed. The event body
     * will contain that document. Use this event for the onDidChangeCustomDocument
     * on your implementation of the `CustomEditorProvider`.
     */
    onDidChangeCustomDocument: vscode.Event<vscode.CustomDocumentEditEvent<D>>;

    /**
     * Register a client on the GLSP-VSCode connector. All communication will subsequently
     * run through the VSCode integration. Clients do not need to be unregistered
     * as they are automatically disposed of when the panel they belong to is closed.
     *
     * @param client The client to register.
     */
    registerClient(client: GlspVscodeClient<D>): void;

    /**
     * Send an action to the client/panel that is currently focused. If no registered
     * panel is focused, the message will not be sent.
     *
     * @param action The action to send to the active client.
     */
    sendActionToActiveClient(action: Action): void;

    /**
     * Saves a document. Make sure to call this function in the `saveCustomDocument`
     * and `saveCustomDocumentAs` functions of your `CustomEditorProvider` implementation.
     *
     * @param document The document to save.
     * @param destination Optional parameter. When this parameter is provided the
     * file will instead be saved at this location.
     * @returns A promise that resolves when the file has been successfully saved.
     */
    saveDocument(document: D, destination?: vscode.Uri): Promise<void>;

    /**
     * Reverts a document. Make sure to call this function in the `revertCustomDocument`
     * functions of your `CustomEditorProvider` implementation.
     *
     * @param document Document to revert.
     * @param diagramType Diagram type as it is configured on the server.
     * @returns A promise that resolves when the file has been successfully reverted.
     */
    revertDocument(document: D, diagramType: string): Promise<void>;
}

GlspVscodeServer

/**
 * The server or server wrapper used by the VSCode integration needs to implement
 * this interface.
 */
export interface GlspVscodeServer {
    /**
     * An event emitter used by the VSCode extension to send messages to the server.
     *
     * You should subscribe to the event attached to this emitter to receive messages
     * from the client/VSCode integration and pass them to the server.
     *
     * Use the properties `onBeforeReceiveMessageFromClient` and `onBeforePropagateMessageToServer`
     * of the GlspVscodeConnector in order to control what messages are propagated
     * and processed.
     */
    readonly onSendToServerEmitter: vscode.EventEmitter<unknown>;

    /**
     * An event the VSCode integration uses to receive messages from the server.
     * The messages are then propagated to the client or processed by the VSCode
     * integration to provide functionality.
     *
     * Fire this event with the message the server wants to send to the client.
     *
     * Use the properties `onBeforeReceiveMessageFromServer` and `onBeforePropagateMessageToClient`
     * of the GlspVscodeConnector in order to control what messages are propagated
     * and processed.
     */
    readonly onServerMessage: vscode.Event<unknown>;
}

GlspVscodeClient

/**
 * Any clients registered on the GLSP VSCode integration need to implement this
 * interface.
 */
export interface GlspVscodeClient<D extends vscode.CustomDocument = vscode.CustomDocument> {
    /**
     * A unique identifier for the client/panel with which the client will be registered
     * on the server.
     */
    readonly clientId: string;

    /**
     * The webview belonging to the client.
     */
    readonly webviewPanel: vscode.WebviewPanel;

    /**
     * The document object belonging to the client;
     */
    readonly document: D;

    /**
     * This event emitter is used by the VSCode integration to pass messages/actions
     * to the client. These messages can come from the server or the VSCode integration
     * itself.
     *
     * You should subscribe to the attached event and pass contents of the event
     * to the webview.
     *
     * Use the properties `onBeforeReceiveMessageFromServer` and `onBeforePropagateMessageToClient`
     * of the GlspVscodeConnector in order to control what messages are propagated
     * and processed.
     */
    readonly onSendToClientEmitter: vscode.EventEmitter<unknown>;

    /**
     * The VSCode integration will subscribe to this event to listen to messages
     * from the client.
     *
     * Fire this event with the message the client wants to send to the server.
     *
     * Use the properties `onBeforeReceiveMessageFromClient` and `onBeforePropagateMessageToServer`
     * of the GlspVscodeConnector in order to control what messages are propagated
     * and processed.
     */
    readonly onClientMessage: vscode.Event<unknown>;
}

Quickstart Components

This package also exposes components which can be taken advantage of if you are using the default GLSP components.

They can be imported using

import * as QuickstartComponents from '@eclipse-glsp/vscode-integration/lib/quickstart-components';

GlspServerLauncher

A small class used to start a default implementation GLSP server.

interface GlspServerLauncher extends vscode.Disposable {
    constructor(options: JavaSocketServerLauncherOptions);

    /**
     * Starts up the server.
     */
    start(): Promise<void>;

    /**
     * Stops the server.
     */
    stop(): void;
}

interface JavaSocketServerLauncherOptions {
    /** Path to the location of the jar file that should be launched as process */
    readonly jarPath: string;
    /** Port on which the server should listen for new client connections */
    readonly serverPort: number;
    /** Set to `true` if server stdout and stderr should be printed in extension host console. Default: `false` */
    readonly logging?: boolean;
    /** Additional arguments that should be passed when starting the server process. */
    readonly additionalArgs?: string[];
}

SocketGlspVscodeServer

A can component that provides the right interface for the GLSP VSCode integration to be used as server and which can connect to a default implementation GLSP server.

interface SocketGlspVscodeServerOptions {
    /** Port of the running server. */
    readonly serverPort: number;
    /** Client ID to register the jsonRPC client with on the server. */
    readonly clientId: string;
    /** Name to register the client with on the server. */
    readonly clientName: string;
}

interface SocketGlspVscodeServer extends GlspVscodeServer, vscode.Disposable {
    constructor(private readonly options: SocketGlspVscodeServerOptions);

    /**
     * Starts up the JSON-RPC client and connects it to a running server.
     */
    start(): Promise<void>;

    /**
     * Stops the client. It cannot be restarted.
     */
    stop(): Promise<void>;
}

GlspEditorProvider

An extensible base class to create a CustomEditorProvider that takes care of diagram initialization and custom document events.

Webview setup needs to be implemented.

export abstract class GlspEditorProvider implements vscode.CustomEditorProvider {
    /**
     * The diagram type identifier the diagram server is responsible for.
     */
    abstract diagramType: string;

    constructor(protected readonly glspVscodeConnector: GlspVscodeConnector);

    /**
     * Used to set up the webview within the webview panel.
     */
    abstract setUpWebview(
        document: vscode.CustomDocument,
        webviewPanel: vscode.WebviewPanel,
        token: vscode.CancellationToken,
        clientId: string
    ): void;
}

More information

For more information, please visit the Eclipse GLSP Umbrella repository and the Eclipse GLSP Website. If you have questions, please raise them in the discussions and have a look at our communication and support options.