// -------------------------------------------------------------------
// Advanced RSS Ticker (Ajax invocation) core file
// Author: Dynamic Drive (http://www.dynamicdrive.com)
// -------------------------------------------------------------------
//Relative URL syntax:
//var lastrssbridgeurl="getRSS.asp"
//Absolute URL syntax. Uncomment below line if you wish to use an absolute reference:
var lastrssbridgeurl="http://www.tr.tcu.edu/getRSS.asp";
var rotateTimer = null;
var refreshAjaxTimer = null;
var errString = '';
var counter = 0;
var parameters = '';
////////////No need to edit beyond here//////////////
function createAjaxObj(){
var httprequest=false;
if (window.XMLHttpRequest){ // if Mozilla, Safari etc
  httprequest=new XMLHttpRequest();
  if (httprequest.overrideMimeType)
    httprequest.overrideMimeType('text/xml');
}
else if (window.ActiveXObject){ // if IE
    var aVersions = [ "MSXML2.XMLHttp.8.0","MSXML2.XMLHttp.7.0","MSXML2.XMLHttp.6.0","MSXML2.XMLHttp.5.0","MSXML2.XMLHttp.4.0","MSXML2.XMLHttp.3.0","MSXML2.XMLHttp","Microsoft.XMLHttp"];
    for (var i = 0; i < aVersions.length; i++) {
        try {
            var httprequest = new ActiveXObject(aVersions[i]);
            return httprequest;
        } catch (oError) {}
    }
    httprequest = false;
}
return httprequest;
}
// -------------------------------------------------------------------
// Main RSS Ticker Object function
// rssticker_ajax(RSS_id, cachetime, divId, divClass, delay, optionallogicswitch)
// -------------------------------------------------------------------
function rssticker_ajax(RSS_id, cachetime, divId, divClass, delay, defaultMessage, logicswitch){
this.RSS_id=RSS_id; //Array key indicating which RSS feed to display
this.cachetime=cachetime; //Time to cache feed, in minutes. 0=no cache.
this.tickerid=divId; //ID of ticker div to display information
this.delay=delay; //Delay between msg change, in miliseconds.
this.defaultMessage=defaultMessage;
this.logicswitch=(typeof logicswitch!="undefined")? logicswitch : "";
this.mouseoverBol=0; //Boolean to indicate whether mouse is currently over ticker (and pause it if it is)
this.pointer=0;
this.opacitysetting=0.2; //Opacity value when reset. Internal use.
this.title=[];
 this.link=[];
 this.description=[];
 this.pubdate=[]; //Arrays to hold each component of an RSS item
this.ajaxobj=createAjaxObj();
document.write('<div id="'+divId+'" class="'+divClass+'" >Initializing ticker...</div>');
if (window.getComputedStyle) //detect if moz-opacity is defined in external CSS for specified class
  this.mozopacityisdefined=(window.getComputedStyle(document.getElementById(this.tickerid), "").getPropertyValue("-moz-opacity")==1)? 0 : 1;
parameters="rssURL="+encodeURIComponent(this.RSS_id);
var instanceOfTicker = this;
if (this.ajaxobj){
  this.ajaxobj.onreadystatechange=function(){instanceOfTicker.initialize();}
  this.ajaxobj.open('GET', lastrssbridgeurl+"?"+parameters, true);
  this.ajaxobj.send(null);
}
refreshAjaxTimer = setInterval(function(){ instanceOfTicker.refresher(); }, ((20*delay)-1));
}
// -------------------------------------------------------------------
// refresher()- Makes more asynchronous GET requests to asp with the supplied parameters
// -------------------------------------------------------------------
rssticker_ajax.prototype.refresher=function(){
  //counter++;
  clearInterval(rotateTimer);
    this.ajaxobj = null;
    this.ajaxobj=createAjaxObj(); 
  if (this.ajaxobj){   
    var instanceOfTicker = this;
    this.ajaxobj.onreadystatechange=function(){instanceOfTicker.initialize();}
    //alert('a');
    this.ajaxobj.open('GET', lastrssbridgeurl+"?"+parameters, true);
    this.ajaxobj.send(null);
    //if (counter > 0) {
    //errString+='counter='+counter+' || ajaxobj='+this.ajaxobj.status+'|'+this.ajaxobj.readyState+'|<br />'
    //document.getElementById('err_msgs').innerHTML=errString;
    //}    
  }
}
// -------------------------------------------------------------------
// initialize()- Initialize ticker method.
// -Gets contents of RSS content and parse it using JavaScript DOM methods 
// -------------------------------------------------------------------
rssticker_ajax.prototype.initialize=function(){ 
//alert(this.ajaxobj.readyState);
if (this.ajaxobj.readyState == 4){ //if request of file completed
if (this.ajaxobj.status==200){ //if request was successful
var xmldata=this.ajaxobj.responseXML;
if(xmldata.getElementsByTagName("item").length==0){ //if no <item> elements found in returned content
document.getElementById(this.tickerid).innerHTML=this.defaultMessage;
return;
}
var instanceOfTicker=this;
this.feeditems=xmldata.getElementsByTagName("item");
//Cycle through RSS XML object and store each peice of an item inside a corresponding array
for (var i=0; i<this.feeditems.length; i++){
this.title[i]=this.feeditems[i].getElementsByTagName("title")[0].firstChild.nodeValue;
this.link[i]=this.feeditems[i].getElementsByTagName("link")[0].firstChild.nodeValue;
this.description[i]=this.feeditems[i].getElementsByTagName("description")[0].firstChild.nodeValue;
try{this.pubdate[i]=this.feeditems[i].getElementsByTagName("pubDate")[0].firstChild.nodeValue;}catch(e){this.pubdate[i]='';}
}
document.getElementById(this.tickerid).onmouseover=function(){instanceOfTicker.mouseoverBol=1;}
document.getElementById(this.tickerid).onmouseout=function(){instanceOfTicker.mouseoverBol=0;}
this.rotatemsg();
rotateTimer = setInterval(function(){instanceOfTicker.rotatemsg();}, this.delay) //update container every second
}
}
}
// -------------------------------------------------------------------
// rotatemsg()- Rotate through RSS messages and displays them
// -------------------------------------------------------------------
rssticker_ajax.prototype.rotatemsg=function(){
var instanceOfTicker=this;
if (this.mouseoverBol==1) //if mouse is currently over ticker, do nothing (pause it)
setTimeout(function(){instanceOfTicker.rotatemsg()}, 100);
else{ //else, construct item, show and rotate it!
var tickerDiv=document.getElementById(this.tickerid);
var linktitle='<div class="rsstitle">'+this.title[this.pointer]+'</div>';
var description='<div class="rssdescription">'+this.description[this.pointer]+'</div>';
var feeddate='<div class="rssdate">'+this.pubdate[this.pointer]+'</div>';
if (this.logicswitch.indexOf("description")==-1) description="";
if (this.logicswitch.indexOf("date")==-1) feeddate="";
var tickercontent=linktitle+feeddate+description; //STRING FOR FEED CONTENTS 
this.fadetransition("reset"); //FADE EFFECT- RESET OPACITY
tickerDiv.innerHTML=tickercontent;
this.fadetimer1=setInterval(function(){instanceOfTicker.fadetransition('up', 'fadetimer1')}, 100); //FADE EFFECT- PLAY IT
this.pointer=(this.pointer<this.feeditems.length-1)? this.pointer+1 : 0;
}
}
// -------------------------------------------------------------------
// fadetransition()- cross browser fade method for IE5.5+ and Mozilla/Firefox
// -------------------------------------------------------------------
rssticker_ajax.prototype.fadetransition=function(fadetype, timerid){
var tickerDiv=document.getElementById(this.tickerid);
if (fadetype=="reset")
this.opacitysetting=0.2;
if (tickerDiv.filters && tickerDiv.filters[0]){
if (typeof tickerDiv.filters[0].opacity=="number") //IE6+
tickerDiv.filters[0].opacity=this.opacitysetting*100;
else //IE 5.5
tickerDiv.style.filter="alpha(opacity="+this.opacitysetting*100+")";
}
else if (typeof tickerDiv.style.MozOpacity!="undefined" && this.mozopacityisdefined){
tickerDiv.style.MozOpacity=this.opacitysetting;
}
if (fadetype=="up")
this.opacitysetting+=0.2;
if (fadetype=="up" && this.opacitysetting>=1)
clearInterval(this[timerid]);
}