electron/docs/api/parent-port.md
David Sanders 993d0337a7
docs: fix broken links (#36519)
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Co-authored-by: Jeremy Rose <nornagon@nornagon.net>

* docs: fix link in examples.md

Co-authored-by: Jeremy Rose <nornagon@nornagon.net>
2022-12-05 13:18:57 -05:00

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# parentPort
> Interface for communication with parent process.
Process: [Utility](../glossary.md#utility-process)
`parentPort` is an [EventEmitter][event-emitter].
_This object is not exported from the `'electron'` module. It is only available as a property of the process object in the Electron API._
```js
// Main process
const child = utilityProcess.fork(path.join(__dirname, 'test.js'))
child.postMessage({ message: 'hello' })
child.on('message', (data) => {
console.log(data) // hello world!
})
// Child process
process.parentPort.on('message', (e) => {
process.parentPort.postMessage(`${e.data} world!`)
})
```
## Events
The `parentPort` object emits the following events:
### Event: 'message'
Returns:
* `messageEvent` Object
* `data` any
* `ports` MessagePortMain[]
Emitted when the process receives a message. Messages received on
this port will be queued up until a handler is registered for this
event.
## Methods
### `parentPort.postMessage(message)`
* `message` any
Sends a message from the process to its parent.
[event-emitter]: https://nodejs.org/api/events.html#events_class_eventemitter