Network.js

var Network = {
	// Host we use for determining connectivity
	pingHost: 'http://www.archmi.com', 
	pingInProgress: false, 

	// If it's PhoneGap or web app environment
	isPhoneGapEnv: network && 'isReachable' in network,  

	// These default values should not be edited, but they may 
	// change at runtime 
	callbacks: {
		success: null, 
		fail: null 
	},

	// Just a general utility. Executes a function only if it exists 
	callIfDefined: function (fn) {
		if (typeof fn === 'function') {
			fn(); 
		}
	},

	// Interpret PhoneGap's network response
	checkPGNetworkResp: function (reachability) {
	    	var networkState = reachability.code || reachability;
	    	var successCodes = [NetworkStatus.REACHABLE_VIA_CARRIER_DATA_NETWORK, 
	    		NetworkStatus.REACHABLE_VIA_WIFI_NETWORK];
	
	    	if (successCodes.indexOf(networkState) > -1) {
	    		this.callIfDefined(this.callbacks.success); 
	    	} else {
	    		this.callIfDefined(this.callbacks.fail); 
	    	}
	},

	runPingTest: function (tries) {
		var _self = this; 
		var tries = tries || 5;
		var currentTry = 0;  

		// Don't allow simultaneous pings
		if (this.pingInProgress === true) {
			return false; 
		}
		this.pingInProgress = true;

		(function ping() {
			// Create an image to use as a test
			var img = new Image(); 
			img.src = _self.pingHost; 

			img.onload = function() {
		    	_self.callIfDefined(_self.callbacks.success); 
		    };
		    img.onerror = function() {
		    	if (++currentTry < tries) {
		    		setTimeout(ping, 100); 
		    	} else {
		    		_self.callIfDefined(_self.callbacks.fail);
		    	} 
		    }; 
		})() 
	},

	getOnlineStatus: function (onSuccess, onFail) {
		this.callbacks.success = onSuccess; 
		this.callbacks.fail = onFail; 

		if (this.isPhoneGapEnv) {
			network.isReachable(this.pingHost, this.checkPGNetworkResp); 
		} else {
			this.runPingTest(5); 
		}
	}	
};