electron/docs/api/ipc-renderer.md

ipcRenderer

Communicate asynchronously from a renderer process to the main process.

Process: Renderer

The ipcRenderer module is an instance of the EventEmitter class. It provides a few methods so you can send synchronous and asynchronous messages from the render process (web page) to the main process. You can also receive replies from the main process.

See ipcMain for code examples.

Methods

The ipcRenderer module has the following method to listen for events and send messages:

ipcRenderer.on(channel, listener)

• channel String
• listener Function
  • event IpcRendererEvent
  • ...args any[]

Listens to channel, when a new message arrives listener would be called with listener(event, args...).

ipcRenderer.once(channel, listener)

• channel String
• listener Function
  • event IpcRendererEvent
  • ...args any[]

Adds a one time listener function for the event. This listener is invoked only the next time a message is sent to channel, after which it is removed.

ipcRenderer.removeListener(channel, listener)

• channel String
• listener Function
  • ...args any[]

Removes the specified listener from the listener array for the specified channel.

ipcRenderer.removeAllListeners(channel)

• channel String

Removes all listeners, or those of the specified channel.

ipcRenderer.send(channel[, arg1][, arg2][, ...])

• channel String
• ...args any[]

Send a message to the main process asynchronously via channel, you can also send arbitrary arguments. Arguments will be serialized as JSON internally and hence no functions or prototype chain will be included.

The main process handles it by listening for channel with the ipcMain module.

ipcRenderer.invoke(channel[, arg1][, arg2][, ...])

• channel String
• ...args any[]

Returns Promise<any> - Resolves with the response from the main process.

Send a message to the main process asynchronously via channel and expect an asynchronous result. Arguments will be serialized as JSON internally and hence no functions or prototype chain will be included.

The main process should listen for channel with ipcMain.handle().

For example:

// Renderer process
ipcRenderer.invoke('some-name', someArgument).then((result) => {
  // ...
})

// Main process
ipcMain.handle('some-name', async (event, someArgument) => {
  const result = await doSomeWork(someArgument)
  return result
})

ipcRenderer.sendSync(channel[, arg1][, arg2][, ...])

• channel String
• ...args any[]

Returns any - The value sent back by the ipcMain handler.

Send a message to the main process synchronously via channel, you can also send arbitrary arguments. Arguments will be serialized in JSON internally and hence no functions or prototype chain will be included.

The main process handles it by listening for channel with ipcMain module, and replies by setting event.returnValue.

Note: Sending a synchronous message will block the whole renderer process, unless you know what you are doing you should never use it.

ipcRenderer.sendTo(webContentsId, channel, [, arg1][, arg2][, ...])

• webContentsId Number
• channel String
• ...args any[]

Sends a message to a window with webContentsId via channel.

ipcRenderer.sendToHost(channel[, arg1][, arg2][, ...])

• channel String
• ...args any[]

Like ipcRenderer.send but the event will be sent to the <webview> element in the host page instead of the main process.

Event object

The documentation for the event object passed to the callback can be found in the ipc-renderer-event structure docs.