Sending a signal to a specific client in a session

To send a signal to a specific client in a session, call the signal() method of the Session object and set the to property of the signal parameter:

The to property is a Connection object corresponding to clients connected to the session that you want to signal. You obtain references to Connection objects when the Session object dispatches sessionConnected and connectionCreated events. You can also obtain the Connection object corresponding to a stream by getting the connection property of the Stream object.

The data property of the signal parameter is the data string you send with the message. This property is optional. If you omit it, the message will be sent without a data payload. The limit to the size of data is 8KB.

The completerHandler parameter of the signal() method is called when the call the method succeeds or fails. The error parameter passed into the completion handler is set to null if the call succeeds. When the call the method fails, the error object has the following properties: code (a numeric error code), message (a string describing the error), and signal (an object corresponding to the signal parameter passed into the signal() method).

Additionally, you can pass in a type property of the signal parameter. This is a string value that clients can filter on when listening for signals:

The maximum length of the type string is 128 bytes, and it must contain only letters (A-Z and a-z), numbers (0-9), '-', '_', and '~'.

For more details, see the documentation for the Session.signal() method.