gristlabs_grist-core/app/client/lib/SafeBrowser.ts

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/**
* The SafeBrowser component implementation is responsible for executing the safeBrowser component
* of a plugin.
*
* A plugin's safeBrowser component is made of one main entry point (the javascript files declares
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* in the manifest), html files and any resources included by the html files (css, scripts, images
* ...). The main script is the main entry point which uses the Grist API to render the views,
* communicate with them en dispose them.
*
* The main script is executed within a WebWorker, and the html files are rendered within webviews
* if run within electron, or iframe in case of the browser.
*
* Communication between the main process and the views are handle with rpc.
*
* If the plugins includes as well an unsafeNode component or a safePython component and if one of
* them registers a function using the Grist Api, this function can then be called from within the
* safeBrowser main script using the Grist API, as described in `app/plugin/Grist.ts`.
*
* The grist API available to safeBrowser components is implemented in `app/plugin/PluginImpl.ts`.
*
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* All the safeBrowser's component resources, including the main script, the html files and any
* other resources needed by the views, should be placed within one plugins' subfolder, and Grist
* should serve only this folder. However, this is not yet implemented and is left as a TODO, as of
* now the whole plugin's folder is served.
*
*/
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// Todo: plugin resources should not be made available on the server by default, but only after
// activation.
// tslint:disable:max-classes-per-file
import { ClientScope } from 'app/client/components/ClientScope';
import { get as getBrowserGlobals } from 'app/client/lib/browserGlobals';
import dom from 'app/client/lib/dom';
import * as Mousetrap from 'app/client/lib/Mousetrap';
import { ActionRouter } from 'app/common/ActionRouter';
import { BaseComponent, BaseLogger, createRpcLogger, PluginInstance, warnIfNotReady } from 'app/common/PluginInstance';
import { tbind } from 'app/common/tbind';
import { getOriginUrl } from 'app/common/urlUtils';
import { GristAPI, RPC_GRISTAPI_INTERFACE } from 'app/plugin/GristAPI';
import { RenderOptions, RenderTarget } from 'app/plugin/RenderOptions';
import { checkers } from 'app/plugin/TypeCheckers';
import { IMsgCustom, IMsgRpcCall, Rpc } from 'grain-rpc';
import { Disposable } from './dispose';
const G = getBrowserGlobals('document', 'window');
/**
* The SafeBrowser component implementation. Responsible for running the script, rendering the
* views, settings up communication channel.
*/
// todo: it is unfortunate that SafeBrowser had to expose both `renderImpl` and `disposeImpl` which
// really have no business outside of this module. What could be done, is to have an internal class
// ProcessManager which will be created by SafeBrowser as a private field. It will manage the
// client processes and among other thing will expose both renderImpl and
// disposeImpl. ClientProcess will hold a reference to ProcessManager instead of SafeBrowser.
export class SafeBrowser extends BaseComponent {
/**
* Create a webview ClientProcess to render safe browser process in electron.
*/
public static createWorker(safeBrowser: SafeBrowser, rpc: Rpc, src: string): WorkerProcess {
return new WorkerProcess(safeBrowser, rpc, src);
}
/**
* Create either an iframe or a webview ClientProcess depending on wether running electron or not.
*/
public static createView(safeBrowser: SafeBrowser, rpc: Rpc, src: string): ViewProcess {
return G.window.isRunningUnderElectron ?
new WebviewProcess(safeBrowser, rpc, src) :
new IframeProcess(safeBrowser, rpc, src);
}
// All view processes. This is not used anymore to dispose all processes on deactivation (this is
// now achieved using `this._mainProcess.autoDispose(...)`) but rather to be able to dispatch
// events to all processes (such as doc actions which will need soon).
private _viewProcesses: Map<number, ClientProcess> = new Map();
private _pluginId: string;
private _pluginRpc: Rpc;
private _mainProcess: WorkerProcess|undefined;
private _viewCount: number = 0;
constructor(
private _plugin: PluginInstance,
private _clientScope: ClientScope,
private _untrustedContentOrigin: string,
private _mainPath: string = "",
private _baseLogger: BaseLogger = console,
rpcLogger = createRpcLogger(_baseLogger, `PLUGIN ${_plugin.definition.id} SafeBrowser:`),
) {
super(_plugin.definition.manifest, rpcLogger);
this._pluginId = _plugin.definition.id;
this._pluginRpc = _plugin.rpc;
}
/**
* Render the file at path in an iframe or webview and returns its ViewProcess.
*/
public createViewProcess(path: string): ViewProcess {
return this._createViewProcess(path)[0];
}
/**
* `receiveAction` handles an action received from the server by forwarding it to the view processes.
*/
public receiveAction(action: any[]) {
for (const view of this._viewProcesses.values()) {
view.receiveAction(action);
}
}
/**
* Renders the file at path and returns its proc id. This is the SafeBrowser implementation for
* the GristAPI's render(...) method, more details can be found at app/plugin/GristAPI.ts.
*/
public async renderImpl(path: string, target: RenderTarget, options: RenderOptions): Promise<number> {
const [proc, viewId] = this._createViewProcess(path);
const renderFunc = this._plugin.getRenderTarget(target, options);
renderFunc(proc.element);
if (this._mainProcess) {
// Disposing the web worker should dispose all view processes that created using the
// gristAPI. There is a flaw here: please read [1].
this._mainProcess.autoDispose(proc);
}
return viewId;
// [1]: When a process, which is not owned by the mainProcess (ie: a process which was created
// using `public createViewProcess(...)'), creates a view process using the gristAPI, the
// rendered view will be owned by the main process. This is not correct and could cause views to
// suddently disappear from the screen. This is pretty nasty. But for following reason I think
// it's ok to leave it for now: (1) fixing this would require (yet) another refactoring of
// SafeBrowser and (2) at this point it is not sure wether we want to keep `render()` in the
// future (we could as well directly register contribution using files directly in the
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// manifest), and (3) plugins are only developed by us, we only have to remember that using
// `render()` is only supported from within the main process (which cover all our use cases so
// far).
}
/**
* Dispose the process using it's proc id. This is the SafeBrowser implementation for the
* GristAPI's dispose(...) method, more details can be found at app/plugin/GristAPI.ts.
*/
public async disposeImpl(procId: number): Promise<void> {
const proc = this._viewProcesses.get(procId);
if (proc) {
this._viewProcesses.delete(procId);
proc.dispose();
}
}
protected doForwardCall(c: IMsgRpcCall): Promise<any> {
if (this._mainProcess) {
return this._mainProcess.rpc.forwardCall(c);
}
// should not happen.
throw new Error("Using SafeBrowser as an IForwarder requires a main script");
}
protected doForwardMessage(c: IMsgCustom): Promise<any> {
if (this._mainProcess) {
return this._mainProcess.rpc.forwardMessage(c);
}
// should not happen.
throw new Error("Using SafeBrowser as an IForwarder requires a main script");
}
protected async activateImplementation(): Promise<void> {
if (this._mainPath) {
const rpc = this._createRpc(this._mainPath);
const src = `plugins/${this._pluginId}/${this._mainPath}`;
// This SafeBrowser object is registered with _pluginRpc as _mainPath forwarder, and
// forwards calls to _mainProcess in doForward* methods (called from BaseComponent.forward*
// methods). Note that those calls are what triggers component activation.
this._mainProcess = SafeBrowser.createWorker(this, rpc, src);
}
}
protected async deactivateImplementation(): Promise<void> {
if (this._mainProcess) {
this._mainProcess.dispose();
}
}
/**
* Creates an iframe or a webview embedding the file at path. And adds it to `this._viewProcesses`
* using `viewId` as key, and registers it as forwarder to the `pluginRpc` using name
* `path`. Unregister both on disposal.
*/
private _createViewProcess(path: string): [ViewProcess, number] {
const rpc = this._createRpc(path);
const url = `${this._untrustedContentOrigin}/plugins/${this._plugin.definition.id}/${path}`
+ `?host=${G.window.location.origin}`;
const viewId = this._viewCount++;
const process = SafeBrowser.createView(this, rpc, url);
this._viewProcesses.set(viewId, process);
this._pluginRpc.registerForwarder(path, rpc);
process.autoDisposeCallback(() => {
this._pluginRpc.unregisterForwarder(path);
this._viewProcesses.delete(viewId);
});
return [process, viewId];
}
/**
* Create an rpc instance and set it up for communicating with a ClientProcess:
* - won't send any message before receiving a ready message
* - has the '*' forwarder set to the plugin's instance rpc
* - has registered an implementation of the gristAPI.
* Returns the rpc instance.
*/
private _createRpc(path: string): Rpc {
const rpc = new Rpc({logger: createRpcLogger(this._baseLogger, `PLUGIN ${this._pluginId}/${path} SafeBrowser:`) });
rpc.queueOutgoingUntilReadyMessage();
warnIfNotReady(rpc, 3000, "Plugin isn't ready; be sure to call grist.ready() from plugin");
rpc.registerForwarder('*', this._pluginRpc);
// TODO: we should be able to stop serving plugins, it looks like there are some resources
// required that should be disposed on component deactivation.
this._clientScope.servePlugin(this._pluginId, rpc);
return rpc;
}
}
/**
* Base class for any client process. `onDispose` allows to register a callback that will be
* triggered when dispose() is called. This is for internally use.
*/
export class ClientProcess extends Disposable {
public rpc: Rpc;
private _safeBrowser: SafeBrowser;
private _src: string;
private _actionRouter: ActionRouter;
public create(...args: any[]): void;
public create(safeBrowser: SafeBrowser, rpc: Rpc, src: string) {
this.rpc = rpc;
this._safeBrowser = safeBrowser;
this._src = src;
this._actionRouter = new ActionRouter(this.rpc);
const gristAPI: GristAPI = {
subscribe: tbind(this._actionRouter.subscribeTable, this._actionRouter),
unsubscribe: tbind(this._actionRouter.unsubscribeTable, this._actionRouter),
render: tbind(this._safeBrowser.renderImpl, this._safeBrowser),
dispose: tbind(this._safeBrowser.disposeImpl, this._safeBrowser),
};
rpc.registerImpl<GristAPI>(RPC_GRISTAPI_INTERFACE, gristAPI, checkers.GristAPI);
this.autoDisposeCallback(() => {
this.rpc.unregisterImpl(RPC_GRISTAPI_INTERFACE);
});
}
public receiveAction(action: any[]) {
this._actionRouter.process(action)
// tslint:disable:no-console
.catch((err: any) => console.warn("ClientProcess[%s] receiveAction: failed with %s", this._src, err));
}
}
/**
* The web worker client process, used to execute safe browser main script.
*/
class WorkerProcess extends ClientProcess {
public create(safeBrowser: SafeBrowser, rpc: Rpc, src: string) {
super.create(safeBrowser, rpc, src);
// Serve web worker script from same host as current page
const worker = new Worker(getOriginUrl(`/${src}`));
worker.addEventListener("message", (e: MessageEvent) => this.rpc.receiveMessage(e.data));
this.rpc.setSendMessage(worker.postMessage.bind(worker));
this.autoDisposeCallback(() => worker.terminate());
}
}
export class ViewProcess extends ClientProcess {
public element: HTMLElement;
}
/**
* The Iframe ClientProcess used to render safe browser content in the browser.
*/
class IframeProcess extends ViewProcess {
public create(safeBrowser: SafeBrowser, rpc: Rpc, src: string) {
super.create(safeBrowser, rpc, src);
const iframe = this.element = this.autoDispose(dom(`iframe.safe_browser_process.clipboard_focus`,
{ src }));
const listener = (event: MessageEvent) => {
if (event.source === iframe.contentWindow) {
this.rpc.receiveMessage(event.data);
}
};
G.window.addEventListener('message', listener);
this.autoDisposeCallback(() => {
G.window.removeEventListener('message', listener);
});
this.rpc.setSendMessage(msg => iframe.contentWindow!.postMessage(msg, '*'));
}
}
/**
* The webview ClientProcess to render safe browser process in electron.
*/
class WebviewProcess extends ViewProcess {
public create(safeBrowser: SafeBrowser, rpc: Rpc, src: string) {
super.create(safeBrowser, rpc, src);
const webview = this.element = this.autoDispose(dom('webview.safe_browser_process.clipboard_focus', {
src,
allowpopups: '',
// Requests with this partition get an extra header (see main.js) to get access to plugin content.
partition: 'plugins',
}));
// Temporaily disable "mousetrap" keyboard stealing for the duration of this webview.
// This is acceptable since webviews are currently full-screen modals.
// TODO: find a way for keyboard events to play nice when webviews are non-modal.
Mousetrap.setPaused(true);
this.autoDisposeCallback(() => Mousetrap.setPaused(false));
webview.addEventListener('ipc-message', (event: any /* IpcMessageEvent */) => {
// The event object passed to the listener is missing proper documentation. In the examples
// listed in https://electronjs.org/docs/api/ipc-main the arguments should be passed to the
// listener after the event object, but this is not happening here. Only we know it is a
// DOMEvent with some extra porperties including a `channel` property of type `string` and an
// `args` property of type `any[]`.
if (event.channel === 'grist') {
rpc.receiveMessage(event.args[0]);
}
});
this.rpc.setSendMessage(msg => webview.send('grist', msg));
}
}