A small utility class that makes working with Google+ Hangouts slightly easier.

SharedData.js

var SharedData = Class.extend({

	_json: [
		"rods",
		"team_config_0",
		"team_config_1"
	],

	init: function() {
		console.log("FoosballSharedData::init");

		var _this = this;
		gapi.hangout.data.onStateChanged.add(function(e){
			_this._onStateChanged(e);
		});
	},

	_onStateChanged: function(event) {
		var key;
		var val;

		for (var i in event.addedKeys) {

			key = event.addedKeys[i].key;
			val = event.addedKeys[i].value;

			if( this._json.indexOf(key) != -1 ) val = JSON.parse(val);

			window.bus.dispatchEvent( { type: 'SharedDataChange.'+key, key:key, value: val } );
		}
	},

	setValue: function(key, val) {
		if( this._json.indexOf(key) != -1 ) val = JSON.stringify(val);

		var delta = {};
		delta[key] = val;

		gapi.hangout.data.submitDelta( delta );
	},

	getValue: function(key) {
		var val = gapi.hangout.data.getValue( key );

		if( this._json.indexOf(key) != -1 ) val = JSON.parse(val);

		return val;
	},

	keyIsDefined: function(key) {
		return gapi.hangout.data.getValue( key ) != undefined;
	}

});