<?php
	header('Content-Type: application/json');

		if (!$this->session->userdata('login')) {
			die(json_encode('no-one is logged in'));
		}

		$pusher = new Pusher\Pusher(
			pusher_key,
			pusher_secret,
			pusher_app_id,
		);

		$presence_data = ['username' => $this->session->userdata('username')];

		echo $pusher->authorizePresenceChannel('channel-demo', $this->input->post('socket_id'), $this->session->userdata('user_id'), $presence_data);
?>

//javascript


var pusher = new Pusher($("#pusher_key").val(), {
  cluster: 'mt1',
  userAuthentication: {
    endpoint: "/pusher/presenceAuth",
    transport: "ajax",
  },
});

pusher.signin();

pusher.connection.bind('state_change', function(states) {
  if (states.current === 'connected') {
    console.log("Connection established!");
  } else {
      console.log('Pusher connection failed:', states.current);
  }
});

var channel = pusher.subscribe($("#channel_pusher").val());
channel.bind($("#event_pusher").val(), function(data) {
  console.log("reached here");
});

pusher.connection.bind('error', function(error) {
  console.log('connection close');
});

channel.bind('pusher:member_added', function(members) {
    console.log('A new member joined:', members);
});

channel.bind('pusher:member_removed', function(members) {
    console.log('A member left:', members);
});