// -------------------------------------------------------------------
// gAjax RSS Feeds Displayer- By Dynamic Drive, available at: http://www.dynamicdrive.com
// Created: July 17th, 2007 Updated: n/a
// -------------------------------------------------------------------

var gfeedfetcher_loading_image="indicator.gif" //Full URL to "loading" image. No need to config after this line!!

google.load("feeds", "1") //Load Google Ajax Feed API (version 1)

function gfeedfetcher(divid, divClass, linktarget){
        this.linktarget=linktarget || "" //link target of RSS entries
        this.feedlabels=[] //array holding lables for each RSS feed
        this.feedurls=[]
        this.feeds=[] //array holding combined RSS feeds' entries from Feed API (result.feed.entries)
        this.feedsfetched=0 //number of feeds fetched
        this.feedlimit=5
        this.showoptions="" //Optional components of RSS entry to show (none by default)
        this.sortstring="date" //sort by "date" by default
        document.write('<div id="'+divid+'" class="'+divClass+'"></div>') //output div to contain RSS entries
        this.feedcontainer=document.getElementById(divid)
        this.itemcontainer="<li>" //default element wrapping around each RSS entry item
}

gfeedfetcher.prototype.addFeed=function(label, url){
        this.feedlabels[this.feedlabels.length]=label
        this.feedurls[this.feedurls.length]=url
}

gfeedfetcher.prototype.filterfeed=function(feedlimit, sortstr){
        this.feedlimit=feedlimit
        if (typeof sortstr!="undefined")
        this.sortstring=sortstr
}

gfeedfetcher.prototype.displayoptions=function(parts){
        this.showoptions=parts //set RSS entry options to show ("date, datetime, time, snippet, label, description")
}

gfeedfetcher.prototype.setentrycontainer=function(containerstr){  //set element that should wrap around each RSS entry item
this.itemcontainer="<"+containerstr.toLowerCase()+">"
}

gfeedfetcher.prototype.init=function(){
        this.feedsfetched=0 //reset number of feeds fetched to 0 (in case init() is called more than once)
        this.feeds=[] //reset feeds[] array to empty (in case init() is called more than once)
        this.feedcontainer.innerHTML='<img src="'+gfeedfetcher_loading_image+'" /> Retrieving RSS feed(s)'
        var displayer=this
        for (var i=0; i<this.feedurls.length; i++){ //loop through the specified RSS feeds' URLs
                var feedpointer=new google.feeds.Feed(this.feedurls[i]) //create new instance of Google Ajax Feed API
                var items_to_show=(this.feedlimit<=this.feedurls.length)? 1 : Math.floor(this.feedlimit/this.feedurls.length) //Calculate # of entries to show for each RSS feed
                if (this.feedlimit%this.feedurls.length>0 && this.feedlimit>this.feedurls.length && i==this.feedurls.length-1) //If this is the last RSS feed, and feedlimit/feedurls.length yields a remainder
                        items_to_show+=(this.feedlimit%this.feedurls.length) //Add that remainder to the number of entries to show for last RSS feed
                feedpointer.setNumEntries(items_to_show) //set number of items to display
                feedpointer.load(function(r){displayer._fetch_data_as_array(r)}) //call Feed.load() to retrieve and output RSS feed
        }
}


gfeedfetcher._formatdate=function(datestr, showoptions){
        var itemdate=new Date(datestr)
        var parseddate=(showoptions.indexOf("datetime")!=-1)? itemdate.toLocaleString() : (showoptions.indexOf("date")!=-1)? itemdate.toLocaleDateString() : (showoptions.indexOf("time")!=-1)? itemdate.toLocaleTimeString() : ""
        return "<span class='datefield'>"+parseddate+"</span>"
}

gfeedfetcher._sortarray=function(arr, sortstr){
        var sortstr=(sortstr=="label")? "ddlabel" : sortstr //change "label" string (if entered) to "ddlabel" instead, for internal use
        if (sortstr=="title" || sortstr=="ddlabel"){ //sort array by "title" or "ddlabel" property of RSS feed entries[]
                arr.sort(function(a,b){
                var fielda=a[sortstr].toLowerCase()
                var fieldb=b[sortstr].toLowerCase()
                return (fielda<fieldb)? -1 : (fielda>fieldb)? 1 : 0
                })
        }
        else{ //else, sort by "publishedDate" property (using error handling, as "publishedDate" may not be a valid date str if an error has occured while getting feed
                try{
                        arr.sort(function(a,b){return new Date(b.publishedDate)-new Date(a.publishedDate)})
                }
                catch(err){}
        }
}

gfeedfetcher.prototype._fetch_data_as_array=function(result){
        var thisfeed=(!result.error)? result.feed.entries : "" //get all feed entries as a JSON array or "" if failed
        if (thisfeed=="") //if error has occured fetching feed

        for (var i=0; i<thisfeed.length; i++) //For each entry within feed
                result.feed.entries[i].ddlabel=this.feedlabels[this.feedsfetched] //extend it with a "ddlabel" property
        this.feeds=this.feeds.concat(thisfeed) //add entry to array holding all feed entries
        this._signaldownloadcomplete() //signal the retrieval of this feed as complete (and move on to next one if defined)
}

gfeedfetcher.prototype._signaldownloadcomplete=function(){
        this.feedsfetched+=1
        if (this.feedsfetched==this.feedurls.length) //if all feeds fetched
                this._displayresult(this.feeds) //display results
}


gfeedfetcher.prototype._displayresult=function(feeds){
        var rssoutput=(this.itemcontainer=="<li>")? "<ul>\n" : ""
        gfeedfetcher._sortarray(feeds, this.sortstring)
        for (var i=0; i<feeds.length; i++){
                var itemtitle="<a href=\"" + feeds[i].link + "\" target=\"" + this.linktarget + "\" class=\"titlefield\">" + feeds[i].title + "</a>"
                var itemlabel=/label/i.test(this.showoptions)? '<span class="labelfield">['+this.feeds[i].ddlabel+']</span>' : " "
                var itemdate=gfeedfetcher._formatdate(feeds[i].publishedDate, this.showoptions)
                var itemdescription=/description/i.test(this.showoptions)? "<br />"+feeds[i].content : /snippet/i.test(this.showoptions)? "<br />"+feeds[i].contentSnippet  : ""
                rssoutput+=this.itemcontainer + itemtitle + " " + itemlabel + " " + itemdate + "\n" + itemdescription + this.itemcontainer.replace("<", "</") + "\n\n"
        }
        rssoutput+=(this.itemcontainer=="<li>")? "</ul>" : ""
        this.feedcontainer.innerHTML=rssoutput
}