geoRssOverlay.js

// GeoRssOverlay: GMaps API extension to display a group of markers from
// a RSS feed
//
// Copyright 2006 Mikel Maron (email: mikel_maron yahoo com)
//
// The original version of this code is called MGeoRSS and can be found
// at the following address:
// http://brainoff.com/gmaps/mgeorss.html
//
// Modified by Andrew Turner to add support for the GeoRss Simple vocabulary
//
// Modified and bundled with YM4R in accordance with the following
// license:
//
// This work is public domain

function GeoRssOverlay(rssurl,icon,proxyurl,options){
    this.rssurl = rssurl;
    this.icon = icon;
    this.proxyurl = proxyurl;
    if(options['visible'] == undefined)
	this.visible = true;
    else
	this.visible = options['visible'];
    this.listDiv = options['listDiv']; //ID of the item list DIV
    this.contentDiv = options['contentDiv']; //ID of the content DIV
    this.listItemClass = options['listItemClass']; //Class of the list item DIV
    this.limitItems = options['limit']; //Maximum number of displayed entries
    this.request = false;
    this.markers = [];
}

GeoRssOverlay.prototype = new GOverlay();

GeoRssOverlay.prototype.initialize=function(map) {
    this.map = map;
    this.load();
}

GeoRssOverlay.prototype.redraw = function(force){
    //nothing to do : the markers are already taken care of
}

GeoRssOverlay.prototype.remove = function(){
    for(var i= 0, len = this.markers.length ; i< len; i++){
	this.map.removeOverlay(this.markers[i]);
    }
}

GeoRssOverlay.prototype.showHide=function() {
    if (this.visible) {
	for (var i=0;i<this.markers.length;i++) {
	    this.map.removeOverlay(this.markers[i]);
	}
	this.visible = false;
    } else {
	for (var i=0;i<this.markers.length;i++) {
	    this.map.addOverlay(this.markers[i]);
	}
	this.visible = true;
    }
}

GeoRssOverlay.prototype.showMarker = function(id){
    var marker = this.markers[id];
    if(marker != undefined){
	GEvent.trigger(marker,"click");
    }
}

GeoRssOverlay.prototype.copy = function(){
    var oCopy = new GeoRssOVerlay(this.rssurl,this.icon,this.proxyurl);
    oCopy.markers = [];
    for(var i = 0 , len = this.markers.length ;i < len ; i++){
	oCopy.markers.push(this.markers[i].copy());
    }
    return oCopy;
}

GeoRssOverlay.prototype.load=function() {
    if (this.request != false) { 
	return; 
    }
    this.request = GXmlHttp.create();
    if (this.proxyurl != undefined) {
	this.request.open("GET",this.proxyurl + '?q=' + encodeURIComponent(this.rssurl),true);
    } else {
	this.request.open("GET",this.rssurl, true);
    }
    var m = this;
    this.request.onreadystatechange = function() {
	m.callback();
    }
    this.request.send(null);
}

GeoRssOverlay.prototype.callback = function() {
    if (this.request.readyState == 4) {
	if (this.request.status == "200") {
	    var xmlDoc = this.request.responseXML;
	    if(xmlDoc.documentElement.getElementsByTagName("item").length != 0){
		//RSS
		var items = xmlDoc.documentElement.getElementsByTagName("item");
	    }else if(xmlDoc.documentElement.getElementsByTagName("entry").length != 0){
		//Atom
		var items = xmlDoc.documentElement.getElementsByTagName("entry");
	    }
	    for (var i = 0, len = this.limitItems?Math.min(this.limitItems,items.length):items.length; i < len; i++) {
		try {
		    var marker = this.createMarker(items[i],i);
		    this.markers.push(marker);
		    if(this.visible){
			this.map.addOverlay(marker);
		    }
		} catch (e) {
		}
	    }
	}
	this.request = false;
    }
}

GeoRssOverlay.prototype.createMarker = function(item,index) {
    
    var title = item.getElementsByTagName("title")[0].childNodes[0].nodeValue;
    if(item.getElementsByTagName("description").length != 0){
	//Rss
	var description = item.getElementsByTagName("description")[0].childNodes[0].nodeValue;
	var link = item.getElementsByTagName("link")[0].childNodes[0].nodeValue;    }else if(item.getElementsByTagName("summary").length != 0){
	//Atom
	var description = item.getElementsByTagName("summary")[0].childNodes[0].nodeValue;
	var link = item.getElementsByTagName("link")[0].attributes[0].nodeValue;
	}
    /* namespaces are handled by spec in moz, not in ie */
    if (navigator.userAgent.toLowerCase().indexOf("msie") < 0) {
       	if(item.getElementsByTagNameNS("http://www.w3.org/2003/01/geo/wgs84_pos#","lat").length != 0){
	    //W3C Geo Vocabulary
	    var lat = item.getElementsByTagNameNS("http://www.w3.org/2003/01/geo/wgs84_pos#","lat")[0].childNodes[0].nodeValue;
	    var lng = item.getElementsByTagNameNS("http://www.w3.org/2003/01/geo/wgs84_pos#","long")[0].childNodes[0].nodeValue;
	}else if(item.getElementsByTagNameNS("http://www.georss.org/georss","point").length != 0){
	    
	    //Simple
	    var latlng = item.getElementsByTagNameNS("http://www.georss.org/georss","point")[0].childNodes[0].nodeValue.split(" ");
	    var lat = latlng[0];
	    var lng = latlng[1];
	}
    } else {
	
	if(item.getElementsByTagName("geo:lat").length != 0){
	    //W3C Geo Vocabulary
	    var lat = item.getElementsByTagName("geo:lat")[0].childNodes[0].nodeValue;
	    var lng = item.getElementsByTagName("geo:long")[0].childNodes[0].nodeValue;
	}else if(item.getElementsByTagName("georss:point").length != 0){
	    //Simple
	    var latlng = item.getElementsByTagName("georss:point")[0].childNodes[0].nodeValue.split(" ");
	    var lat = latlng[0];
	    var lng = latlng[1];
	}
    }
    
    var point = new GLatLng(parseFloat(lat), parseFloat(lng));
    var marker = new GMarker(point,{'title': title});
    var html = "<a href=\"" + link + "\">" + title + "</a><p/>" + description;
    
    if(this.contentDiv == undefined){
	GEvent.addListener(marker, "click", function() {
	    marker.openInfoWindowHtml(html);
	});
    }else{
	var contentDiv = this.contentDiv;
	GEvent.addListener(marker, "click", function() {
	    document.getElementById(contentDiv).innerHTML = html;
	});
    }
    
    if(this.listDiv != undefined){
	var a = document.createElement('a'); 
	a.innerHTML = title;
	a.setAttribute("href","#");
	var georss = this;
	a.onclick = function(){
	    georss.showMarker(index);
	    return false;
	};
	var div = document.createElement('div');
	if(this.listItemClass != undefined){
	    div.setAttribute("class",this.listItemClass);
	}
	div.appendChild(a);
	document.getElementById(this.listDiv).appendChild(div);
    }
    
    return marker;
}