subscribeRemoteCall

Publish & Subscribe Remote Call

This example demonstrates the send API of the publisher in the Red5 Pro HTML SDK. Using send, a publisher can send a message object to any currently subscribed clients.

Please refer to the Basic Subscriber Documentation and Basic Publisher Documentation to learn more about the basic setup.

Example Code

Publisher

• index.html
• index.js

Subscriber

• index.html
• index.js

Running the example

Two clients are required to run this example: one as a publisher, and the other as a subscriber.

Connect the first client (publisher) with the Publish - Remote Call example. On the second lient (subscriber) use the Subscribe - Remote Call example.

Touch the preview on the publisher screen to display a label on the subscriber screen where the publisher touched.

Using the send API

Once the broadcast stream has connected you are able to dispatch messages to any connected subscribers. Sending the message is a simple call:

send('whateverFunctionName', {
  message: 'The publisher wants your attention',
  touchX: event.offsetX / elem.clientWidth,
  touchY: event.offsetY / elem.clientHeight,
})

Method signature

The method signature for the send API is:

Param	Description
methodName	The name of the method associated with the data to be parsed on the subscriber clients.
data	A javascript Object describing the message data to send to subscriber clients.

If the subscribing client is browser-based, a Subscriber.Send.Invoke event is triggered on the subscriber.

The methodName you provide will be included as the SubscriberEvent:methodName of the Subscriber.Send.Invoke event if the client is browser-based. For iOS and Android subscribers, it will be invoked on the R5Stream:client instance.

The structure of data can be any javascript Object. The data will be serialized and unpacked appropriately on the corresponding clients and given as the first argument when invoking the methodName.

You should not send the data object as a String.

Receiving the message

On the browser-based subscriber client, you will need to define the event responder for Subscriber.Send.Invoke and handle the event properties to determine the methodName being invoked. In using the Red5 Pro HTML SDK:

subscriber.on(
  red5pro.SubscriberEventTypes.SUBSCRIBE_SEND_INVOKE,
  sendClientHandler
)

var sendClientHandler = function (event) {
  var eventData = event.data
  var msg = eventData.data
  var methodName = eventData.methodName
  if (methodName === 'whateverFunctionName') {
    var elem = document.getElementById('red5pro-subscriber-video')
    messageCallout.innerText = msg.message
    messageCallout.style.left =
      elem.offsetLeft + elem.clientWidth * msg.touchX + 'px'
    messageCallout.style.top =
      elem.offsetTop + elem.clientHeight * msg.touchY + 'px'
  }
}