Xibo Communication Framework

A library written for web based players that will contain communication between the player and the CMS.

Modules

• XMR - Basic implementation
• XMDS - To follow

XMR

Start using XMR from this library by installing it through npm to our web based player (e.g. ChromeOS Player)

npm install @xibosignage/xibo-communication-framework

Once the package is installed, we can import the XMR object from where we want to initialize it in our player.

import {Xmr} from '@xibosignage/xibo-communication-framework';

We can then create an instance of XMR object to manage the XMR state.

let xmr = new Xmr(config.xmrChannel || ‘unknown’);

// Initialize XMR
await xmr.init();

config.xmrChannel is a randomly generated string for the XMR channel name.

Finally, we can start XMR when our display has been registered through the call on the XMDS register display. In the case of the ChromeOS player, we are doing the following after successful display registration.

Connected to a local development CMS the value for xmrWebSocketAddress would be ws://localhost/xmr

// Web Sockets are only supported by the CMS if the XMDS version is 7, otherwise ZeroMQ web sockets should be used.
// Use ws not http 
const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';

// If the CMS has sent an alternative WS address, use that instead.
let xmrWebSocketAddress = config.getSetting(
  'xmrWebSocketAddress',
  cmsUrl.replace(window.location.protocol, protocol) + '/xmr'
);
xmr.start(xmrWebSocketAddress, config.getSetting('xmrCmsKey', 'n/a'));

XMR Events

There are existing events that are already defined that correspond to actions done from the CMS.

collectNow

An action in the CMS through a Display that overrides the collection interval function.

screenShot

An action in the CMS through a Display that requests a screenshot from the player and made available in the CMS for the related display.

licenceCheck

An action in the CMS through a Display that checks the licence of the player.

showStatusWindow

A Display command “Show Status Window” which shows the status window in the player. (In this case, ChromeOS player)

forceUpdateChromeOS

A Display command “Force update ChromeOS” that forces the ChromeOS player to update to the set version from the display settings.

These events are available through this TypeScript interface below. We can add events through this interface.

export interface XmrEvents {
  connected: () => void;
  disconnected: () => void;
  error: (e: string) => void;
  statusChange: (status: string) => void;
  collectNow: () => void;
  screenShot: () => void;
  licenceCheck: () => void;
  showStatusWindow: (timeout: number) => void;
  forceUpdateChromeOS: () => void;
}

On the consuming player, we can listen to these events and make necessary actions using a callback.

...
xmr.on('collectNow', () => {
  xmds.collectNow();
});
...