electron-rpc

electron-rpc is an module that enables RPC style remote API call for electron.

Inspired by vscode's RPC module, try to make a convenient, easy to use but yet powerful RPC library.

features:

• developer friendly design for TypeScript, no IDL needed
• use remote service just like a local object, no boilerplate or glue code needed
• strong type, compile-time type check with TypeScript interface
• auto Promisify TypeScript interface, with events on/off method overloading support
• event listen/unlisten
• dynamic service object creation, and lifetime management by GC (FinalizationRegistry)
• support electron sanbox, no nodeintegration required

Quick Start

let's say if you have these services

interface IShell {
  openExternal(url: string): Promise<void>;
}

interface IApp {
  getPath(name: PathNames): string;
  createMyShell(): IShell;
}

interface IWindow {
  maximize(): void;
  getBounds(): Electron.Rectangle;
  on(event: "resize", cb: (data: Electron.Rectangle) => void): void;
  once(event: "resize", cb: (data: Electron.Rectangle) => void): void;
  off(eventName: string, listener: (arg?: any) => void): void;
}

main process, implement your service

// a normal class that's a service
class Shell implements IShell {
  public openExternal(url: string) {
    return shell.openExternal(url);
  }
}

class AppService implements IApp {
  getPath(name: PathNames): string {
    return app.getPath(name);
  }
  //return a dynamic service
  createMyShell() {
    const shell = new Shell();
    return markDynamicService(shell);
  }
}

//a service that need to known the context of caller
class WindowService implements IRpcService<IpcContext> {
  call(ctx: IpcContext, method: string, args?: any): any {
    const browser = this.getBrowser(ctx);
    switch (method) {
      case "maximize":
        return browser.maximize();
      case "getBounds":
        return browser.getBounds();
        throw new Error(`${method} not found`)
    }
  }
  listen(ctx: IpcContext, event: string, cb: EventCB<any>): void {
    ...
  }

}

in main process, register your service

import { createRpcService, Server } from "electron-rpc/main";

const rpc = new Server();
rpc.registerService("window", new WindowService());
rpc.registerService("shell", createRpcService(new Shell()));
rpc.registerService("app", createRpcService(new AppService()));

in renderer process, simple setup the client

//setup client with few lines of code
import { Client, ProxyHelper } from "electron-rpc/renderer";
import EventEmitter from "eventemitter3";
const _client = new Client(window.ipcRenderer, new EventEmitter());
const rpc = {
  toService: (name) => {
    return ProxyHelper.createProxyService(_client, name);
  },
};

you are ready to go, use your remote service like native object

//use service
const windowService = rpc.toService<IWindow>("window");
windowService.maximize();
windowService.on("resize", (rect:) => {
  console.log(rect);
});
const bounds = await windowService.getBounds();
console.log(bounds);

//get dynamic service
const app = rpc.toService<IApp>('app')
const shell = ProxyHelper.asProxyService(await app.createMyShell())
shell.openExternal('https://google.com')

the service object you get has TypeScript interface, so you can enjoy intellisense code completion and typecheck!

About how the Promised interface is generated

in the above example, the interface of windowService is ike this

interface PromisifiedIWindow = {
  maximize(): Promise<void>;
  getBounds(): Promise<Electron.Rectangle>;
  on(event: "resize", cb: (data: Electron.Rectangle) => void): void;
  once(event: "resize", cb: (data: Electron.Rectangle) => void): void;
  off(eventName: string, listener: (arg?: any) => void): void;
}

but is generated automatically, and it event support on/off method overloading!

checkout this document about details: https://github.com/hiitiger/electron-demos/tree/master/ipc-async-interface-proxy

Note

We can implement our own IIpcConnection, so this can support other JavaScript environment like nodejs, browser/CEF(websocket with backend) and etc.