electron/docs/api/ipc-renderer.md

ipc (renderer)

The ipc module provides a few methods so you can send synchronous and asynchronous messages to the browser, and also receive messages sent from browser. If you want to make use of modules of browser from renderer, you might consider using the remote module.

See ipc (browser) for examples.

ipc.send(channel[, args...])

Send args.. to the web page via channel in asynchronous message, the browser process can handle it by listening to the channel event of ipc module.

ipc.sendSync(channel[, args...])

Send args.. to the web page via channel in synchronous message, and returns the result sent from browser. The browser process can handle it by listening to the channel event of ipc module, and returns by setting event.returnValue.

Note: Usually developers should never use this API, since sending synchronous message would block the whole web page.