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.
The ipcRenderer
module has the following method to listen for events and send messages:
ipcRenderer.on(channel, listener)
channel
Stringlistener
FunctionListens to channel
, when a new message arrives listener
would be called with
listener(event, args...)
.
ipcRenderer.once(channel, listener)
channel
Stringlistener
FunctionAdds 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
Stringlistener
FunctionRemoves the specified listener
from the listener array for the specified
channel
.
ipcRenderer.removeAllListeners(channel)
channel
StringRemoves 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[]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(windowId, channel, [, arg1][, arg2][, ...])
windowId
Numberchannel
String...args
any[]Sends a message to a window with windowid
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.