// -------------------------------------------------------------------
// 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
        alert("Google Feed API Error: " + result.error.message)
    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
}