electron-promise-ipc

Promise-y IPC calls in Electron.

Installation

npm install --save electron-promise-ipc

Usage

The most common use case: from the renderer, get data from the main process as a promise.

// in main process
import promiseIpc from 'electron-promise-ipc';
import fsp from 'fs-promise';

promiseIpc.on('writeSettingsFile', (newSettings) => {
  return fsp.writeFile('~/.settings', newSettings);
});

// in renderer
import promiseIpc from 'electron-promise-ipc';

promiseIpc.send('writeSettingsFile', '{ "name": "Jeff" }')
  .then(() => console.log('You wrote the settings!'))
  .catch(e => console.error(e));

You can also send data from the main process to a renderer, if you pass in its WebContents object.

// in main process
import promiseIpc from 'electron-promise-ipc';

promiseIpc.send('getRendererData', webContentsForRenderer)
  .then(rendererData => console.log(rendererData))
  .catch(e => console.error(e));

// in renderer
import promiseIpc from 'electron-promise-ipc';

promiseIpc.on('getRendererData', () => {
  return getSomeSuperAwesomeRendererData();
});

Any arguments to send() will be passed directly to the event listener from on(). If there is an error thrown in the main process's listener, or if the listener returns a rejected promise (e.g., lack of permissions for a file read), then the send() promise is rejected with the same error.

Note that because this is IPC, only JSON-serializable values can be passed as arguments or data. Classes and functions will generally not survive a round of serialization/deserialization.

Advanced usage

By default, the promise will wait forever for the other process to return it some data. If you want to set a timeout (after which the promise will be rejected automatically), you can create another instance of PromiseIpc like so:

// main process code remains the same
import promiseIpc from 'electron-promise-ipc';

promiseIpc.on('someRoute', () => {
  return someOperationThatNeverCompletesUhOh();
});

// in renderer - timeout is specified on the side that requests the data
import { PromiseIpc } from 'electron-promise-ipc';

const promiseIpc = new PromiseIpc({ maxTimeoutMs: 2000 });

promiseIpc.send('someRoute', '{ "name": "Jeff" }')
  .then(() => console.log('You wrote the settings!'))
  .catch(e => console.error(e)); // will error out after 2 seconds

License

MIT

hyperlink / electron-promise-ipc