electron-preload-link

A simple utility to send and listen for messages via the window.postMessage API. Useful for communication between electron preload scripts and sandboxed + context isolated child processes.

Example:

Child Process

const preloadLink = require('electron-preload-link')

preloadLink.on('shutdown-imminent', (timeRemaining) => {
  window.alert(
    `You have ${timeRemaining}ms before this process is shut down.`
  )
})

function handleSuccess(clipboardContents) {
  window.alert(`The contents of your clipboard are: ${clipboardContents}`)
  preloadLink.off('clipboard-request-fail', handleFail)
}

function handleFail(err) {
  console.error(err)
  window.alert('Failed to get clipboard contents!')
  preloadLink.off('clipboard-request-success', handleSuccess)
}

preloadLink.once('clipboard-request-success', handleSuccess)
preloadLink.once('clipboard-request-fail', handleFail)
preloadLink.emit('clipboard-request')

Preload Script

const preloadLink = require('electron-preload-link')
const { clipboard } = require('electron')

preloadLink.emit('shutdown-imminent', 60 * 1000)

preloadLink.on('clipboard-request', () => {
  try {
    const clipboardContent = clipboard.readText()
    preloadLink.emit('clipboard-request-success', clipboardContent)
  } catch (err) {
    preloadLink.emit('clipboard-request-fail', err)
  }
})