var RSSRequestObject = false; // XMLHttpRequest Object
var Backend = 'extensions/GoogleCalendar/eventrss.php'; // Backend url
window.setInterval("update_timer()", 1200000); // update the data every 20 mins


if (window.XMLHttpRequest) // try to create XMLHttpRequest
	RSSRequestObject = new XMLHttpRequest();

if (window.ActiveXObject)	// if ActiveXObject use the Microsoft.XMLHTTP
	RSSRequestObject = new ActiveXObject("Microsoft.XMLHTTP");


/*
* onreadystatechange function
*/
function ReqChange() {

	// If data received correctly
	if (RSSRequestObject.readyState==4) {
	
		// if data is valid
		if (RSSRequestObject.responseText.indexOf('invalid') == -1) 
		{ 	
			// Parsing Feeds
			var node = RSSRequestObject.responseXML.documentElement; 
			
			// Get the calendar title
			var title = node.getElementsByTagName('title').item(0).firstChild.data;
			
			content = '<!--'+title+'-->';
	
	
			// Browse events
			var items = node.getElementsByTagName('entry');
			if (items.length == 0) {
				content += '<li><div class=error>No events</div></li>';
			} else {
				content += '';
				for (var n=items.length-1; n >= 0; n--)
				{
					var itemTitle = items[n].getElementsByTagName('title').item(0).firstChild.data;
					var itemLink = items[n].getElementsByTagName('link').item(0).getAttribute('href');
					try 
					{
                                        var atomdate = items[n].getElementsByTagName('published').item(0).firstChild.data;
                                        var itemPubDateDay = atomdate.substr(0, 10);
                                        var itemPubDateTime = atomdate.substr(11, 8);
					} 
					catch (e) 
					{ 
						var itemPubDateDay = '';
                                                var itemPubDateTime = '';
					}
					
				
					content += itemPubDateDay+':  <a href="'+itemLink+'">'+itemTitle+'</a><br>';
				}
				
	
				content += '</li>';
			}
			// Display the result
			document.getElementById("ajaxreader").innerHTML = content;

			// Tell the reader the everything is done
			document.getElementById("status").innerHTML = "Done.";
			
		}
		else {
			// Tell the reader that there was error requesting data
			document.getElementById("status").innerHTML = "<div class=error>Error requesting data.<div>";
		}
		
		HideShow('status');
	}
	
}

/*
* Main AJAX RSS reader request
*/
function RSSRequest() {

	// change the status to requesting data
	HideShow('status');
	document.getElementById("status").innerHTML = "Requesting data ...";
	
	// Prepare the request
	RSSRequestObject.open("GET", Backend , true);
	// Set the onreadystatechange function
	RSSRequestObject.onreadystatechange = ReqChange;
	// Send
	RSSRequestObject.send(null); 
}

/*
* Timer
*/
function update_timer() {
	RSSRequest();
}


function HideShow(id){
	var el = GetObject(id);
	if(el.style.display=="none")
	el.style.display='';
	else
	el.style.display='none';
}

function GetObject(id){
	var el = document.getElementById(id);
	return(el);
}