vertx / io.vertx.reactivex.core.http / WebSocket / binaryMessageHandler

# binaryMessageHandler

`open fun binaryMessageHandler(handler: Handler<Buffer>): WebSocketBase`

Overrides WebSocketBase.binaryMessageHandler

Set a binary message handler on the connection. This handler serves a similar purpose to `io.vertx.reactivex.core.http.WebSocket#handler` except that if a message comes into the socket in multiple frames, the data from the frames will be aggregated into a single buffer before calling the handler (using `io.vertx.reactivex.core.http.WebSocketFrame#isFinal` to find the boundaries).

### Parameters

`handler` - the handler

Return
a reference to this, so the API can be used fluently