81 lines
2.5 KiB
Markdown
81 lines
2.5 KiB
Markdown
# ipcRenderer
|
|
|
|
> Communicate asynchronously from a renderer process to the main process.
|
|
|
|
Process: [Renderer](../glossary.md#renderer-process)
|
|
|
|
The `ipcRenderer` module is an instance of the
|
|
[EventEmitter](https://nodejs.org/api/events.html#events_class_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](ipc-main.md) 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
|
|
|
|
Listens to `channel`, when a new message arrives `listener` would be called with
|
|
`listener(event, args...)`.
|
|
|
|
### `ipcRenderer.once(channel, listener)`
|
|
|
|
* `channel` String
|
|
* `listener` Function
|
|
|
|
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
|
|
|
|
Removes the specified `listener` from the listener array for the specified
|
|
`channel`.
|
|
|
|
### `ipcRenderer.removeAllListeners([channel])`
|
|
|
|
* `channel` String (optional)
|
|
|
|
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 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.
|
|
|
|
### `ipcRenderer.sendSync(channel[, arg1][, arg2][, ...])`
|
|
|
|
* `channel` String
|
|
* `...args` any[]
|
|
|
|
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.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.
|