electron/docs/api/browser/ipc-browser.md

ipc (browser)

The ipc module allows developers to send asynchronous messages to renderers. To avoid possible dead-locks, it's not allowed to send synchronous messages in browser.

Event: 'message'

• processId Integer
• routingId Integer

Emitted when renderer sent a message to the browser.

Event: 'sync-message'

• event Object
• processId Integer
• routingId Integer

Emitted when renderer sent a synchronous message to the browser. The receiver should store the result in event.returnValue.

Note: Due to the limitation of EventEmitter, returning value in the event handler has no effect, so we have to store the result by using the event parameter.

ipc.send(processId, routingId, [args...])

• processId Integer
• routingId Integer

Send args... to the renderer specified by processId and routingId and return immediately, the renderer should handle the message by listening to the message event.

ipc.sendChannel(processId, routingId, channel, [args...])

• processId Integer
• routingId Integer
• channel String

This is the same with ipc.send, except that the renderer should listen to the channel event. The ipc.send(processId, routingId, args...) can be seen as ipc.sendChannel(processId, routingId, 'message', args...).

Note: If the the first argument (e.g. processId) is a BrowserWindow, ipc.sendChannel would automatically get the processId and routingId from it, so you can send a message to window like this:

ipc.sendChannel(browserWindow, 'message', ...);