Google Maps API wil Drop down selection

Hi,

I am a noob when it comes to google maps. I would like to create something like this.

http://www.barcelona.com/map

Which will show all markers in the same catergory when I choose from the drop down menu but the problem is I cannot do it. Been working on it for 5 hours now and I still cannot do it which is very frustrating.

Can someone show me how to do it? or rather send a sample code that can do the selection. Your help is very much appreciated.

Don't give me a complicated one. A simple one will be enough because still a noob. Below is a sample script.

Thank you.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script src="http://maps.google.com/maps?file=api&amp;v=2.x&amp;key=ACTUALKEYHERE" type="text/javascript"></script>
<script type="text/javascript">
    //<![CDATA[
 
latitude = 48.89364;
longitude = 2.33739;
 
var mapshow = document.markerType.value;
 
function initialize() {
	if (GBrowserIsCompatible()) {
		var map = new GMap2(document.getElementById("map_canvas"));
		var bounds = new GLatLngBounds();
		map.setCenter(new GLatLng(latitude,longitude), 16);
 
		var bounds = map.getBounds();
		var southWest = bounds.getSouthWest();
		var northEast = bounds.getNorthEast();
		var lngSpan = northEast.lng() - southWest.lng();
		var latSpan = northEast.lat() - southWest.lat();
 
		function createMarker(point,name,html) {
			var marker = new GMarker(point);
			GEvent.addListener(marker, "click", function() {
				marker.openInfoWindowHtml(html);
			});
			i++;
			return marker;
		}
 
		
		if (mapshow==1)
		{
		var i = 0;
var markers=new Array(4);
markers[0] = new Array(48.89494,2.33472,"<center>Marker1</center>");
markers[0] = new Array(48.89116,2.33438,"<center>Marker2</center>");
		}
		
		if (mapshow==2)
		{
		var i = 0;
var markers=new Array(4);
markers[0] = new Array(48.89136,2.34532,"<center>Marker1</center>");
markers[0] = new Array(48.88851,2.34537,"<center>Marker2</center>");
		}
 
		while (i < markers.length) {
			var lat = parseFloat(markers[i][0]);
			var lng = parseFloat(markers[i][1]);
			var point = new GLatLng(lat,lng);
			var html = markers[i][2];
			var label = "";
			var marker = createMarker(point,label,html);
			map.addOverlay(marker);
			bounds.extend(marker.getPoint());
		}
 
      map.setZoom(map.getBoundsZoomLevel(bounds));
      map.setCenter(bounds.getCenter());
 
		map.addControl(new GScaleControl());
		map.addControl(new GLargeMapControl());
		map.addControl(new GOverviewMapControl());
		map.addControl(new GMapTypeControl());
	}
}
    //]]>
    </script>
</head>
 
<body onLoad="initialize()" onUnload="GUnload()">
  <select name="mapshow" onchange="initialize()">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
  </select>
<p>
<div class="picborder" id="map_canvas" style="width: 600px; height: 500px"></div>
</body>
</html>

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openaccount1Asked:
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b0lsc0ttIT ManagerCommented:
Are you having a problem putting markers on the map or something else?
bol
0
openaccount1Author Commented:
yes, the markers just won't load in the map
0
b0lsc0ttIT ManagerCommented:
Let me know how the changes below work.  The map and markers show but I am not sure if you get all the markers you want and if the result is what you need.  We might need to fix a little more.
The problems were in the script and the select tag.  Please note the changes in the snippet below.  Let me know if you don't catch them all or have a question.
bol

<script type="text/javascript">
    //<![CDATA[
 
latitude = 48.89364;
longitude = 2.33739;
 
 
function initialize() {
	if (GBrowserIsCompatible()) {
		var map = new GMap2(document.getElementById("map_canvas"));
		var bounds = new GLatLngBounds();
		map.setCenter(new GLatLng(latitude,longitude), 16);
 
		var bounds = map.getBounds();
		var southWest = bounds.getSouthWest();
		var northEast = bounds.getNorthEast();
		var lngSpan = northEast.lng() - southWest.lng();
		var latSpan = northEast.lat() - southWest.lat();
 
		function createMarker(point,name,html) {
			var marker = new GMarker(point);
			GEvent.addListener(marker, "click", function() {
				marker.openInfoWindowHtml(html);
			});
			i++;
			return marker;
		}
 
		var mapshow = document.getElementById('markerType').value;
		
		if (mapshow==1)
		{
		var i = 0;
var markers=new Array();
markers[0] = new Array(48.89494,2.33472,"<center>Marker1</center>");
markers[1] = new Array(48.89116,2.33438,"<center>Marker2</center>");
		}
		
		if (mapshow==2)
		{
		var i = 0;
var markers=new Array();
markers[0] = new Array(48.89136,2.34532,"<center>Marker1</center>");
markers[1] = new Array(48.88851,2.34537,"<center>Marker2</center>");
		}
 
		for (var i=0; i < markers.length; i++) {
			var lat = parseFloat(markers[i][0]);
			var lng = parseFloat(markers[i][1]);
			var point = new GLatLng(lat,lng);
			var html = markers[i][2];
			var label = "";
			var marker = createMarker(point,label,html);
			map.addOverlay(marker);
			bounds.extend(marker.getPoint());
		}
 
      map.setZoom(map.getBoundsZoomLevel(bounds));
      map.setCenter(bounds.getCenter());
 
		map.addControl(new GScaleControl());
		map.addControl(new GLargeMapControl());
		map.addControl(new GOverviewMapControl());
		map.addControl(new GMapTypeControl());
	}
}
    //]]>
    </script>
</head>
 
<body onLoad="initialize()" onUnload="GUnload()">
  <select name="markerType" id="markerType" onchange="initialize()">

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openaccount1Author Commented:
The map change action is now working but:

1. The map does not show when page is loaded.
2. When I select one of the selections, the map is changing but only 1 marker is shown per selection.

Below is the updated code.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
<script src="http://maps.google.com/maps?file=api&v=1&key=" type="text/javascript"></script>
<script type="text/javascript">
    //<![CDATA[
 
latitude = 48.89364;
longitude = 2.33739;
 
function initialize() {
        if (GBrowserIsCompatible()) {
                var map = new GMap2(document.getElementById("map_canvas"));
                var bounds = new GLatLngBounds();
                map.setCenter(new GLatLng(latitude,longitude), 16);
 
                var bounds = map.getBounds();
                var southWest = bounds.getSouthWest();
                var northEast = bounds.getNorthEast();
                var lngSpan = northEast.lng() - southWest.lng();
                var latSpan = northEast.lat() - southWest.lat();
 
                function createMarker(point,name,html) {
                        var marker = new GMarker(point);
                        GEvent.addListener(marker, "click", function() {
                                marker.openInfoWindowHtml(html);
                        });
                        i++;
                        return marker;
                }
 
                var mapshow = document.getElementById('markerType').value;
                
                if (mapshow==1)
                {
                var i = 0;
var markers=new Array(2);
markers[0] = new Array(48.89494,2.33472,"<center>Marker1</center>");
markers[1] = new Array(48.89116,2.33438,"<center>Marker2</center>");
                }
                
                if (mapshow==2)
                {
                var i = 0;
var markers=new Array(2);
markers[0] = new Array(48.89136,2.34532,"<center>Marker1</center>");
markers[1] = new Array(48.88851,2.34537,"<center>Marker2</center>");
                }
 
                for (var i=0; i < markers.length; i++) {
                        var lat = parseFloat(markers[i][0]);
                        var lng = parseFloat(markers[i][1]);
                        var point = new GLatLng(lat,lng);
                        var html = markers[i][2];
                        var label = "";
                        var marker = createMarker(point,label,html);
                        map.addOverlay(marker);
                        bounds.extend(marker.getPoint());
                }
 
      map.setZoom(map.getBoundsZoomLevel(bounds));
      map.setCenter(bounds.getCenter());
 
                map.addControl(new GScaleControl());
                map.addControl(new GLargeMapControl());
                map.addControl(new GOverviewMapControl());
                map.addControl(new GMapTypeControl());
        }
}
    //]]>
 
    </script> 
</head>
 
<body>
  <select name="markerType" id="markerType" onchange="initialize()">
    <option value="1" selected="selected">1</option>
    <option value="2">2</option>
  </select> 
<div class="picborder" id="map_canvas" style="width: 600px; height: 500px"></div>
</body>
</html>

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0
b0lsc0ttIT ManagerCommented:
Part of the problem was in the code I gave you.  I noticed the 2nd marker missing.  Please look at and use the changes in the code below.  Let me know if it doesn't take care of all the problems (I did not look at the last snippet you posted).

bol

function initialize() {
	if (GBrowserIsCompatible()) {
		var map = new GMap2(document.getElementById("map_canvas"));
		var bounds = new GLatLngBounds();
		map.setCenter(new GLatLng(latitude,longitude), 16);
 
		var bounds = map.getBounds();
		var southWest = bounds.getSouthWest();
		var northEast = bounds.getNorthEast();
		var lngSpan = northEast.lng() - southWest.lng();
		var latSpan = northEast.lat() - southWest.lat();
 
		function createMyMarker(point,name,html) {
			var marker = new GMarker(point);
			GEvent.addListener(marker, "click", function() {
				marker.openInfoWindowHtml(html);
			});
			return marker;
		}
 
		var mapshow = document.getElementById('markerType').value;
		
		if (mapshow==1)
		{
var markers=new Array();
markers[0] = new Array(48.89494,2.33472,"<center>Marker1</center>");
markers[1] = new Array(48.89116,2.33438,"<center>Marker2</center>");
		}
		
		if (mapshow==2)
		{
var markers=new Array();
markers[0] = new Array(48.89136,2.34532,"<center>Marker1</center>");
markers[1] = new Array(48.88851,2.34537,"<center>Marker2</center>");
		}
		for (var i=0; i < markers.length; i++) {
			var lat = parseFloat(markers[i][0]);
			var lng = parseFloat(markers[i][1]);
			var point = new GLatLng(lat,lng);
			var html = markers[i][2];
			var label = "";
			var marker = createMyMarker(point,label,html);
			map.addOverlay(marker);
			bounds.extend(marker.getPoint());
		}
 
      map.setZoom(map.getBoundsZoomLevel(bounds));
      map.setCenter(bounds.getCenter());
 
		map.addControl(new GScaleControl());
		map.addControl(new GLargeMapControl());
		map.addControl(new GOverviewMapControl());
		map.addControl(new GMapTypeControl());
	}
}

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openaccount1Author Commented:
ok all markers are appearing now but when I add another marker still only 2 marker is shown. I may add markers on one selection and not on the others so is it possible to make the code accept any number of markers.

Also the map is not shown when page is first loaded.
0
b0lsc0ttIT ManagerCommented:
It shows for me when first loaded.  Also the number of markers shouldn't matter unless you are adding the integer back to the parentheses when you make the array.  Notice my code removes it because it was causing  a problem and isn't needed (or wanted) if the array could have various numbers of keys.
What is your code for the page I provided?  Hopefully the problems are just something missing from it.  Please review the changes I made and code I provided (in my last snippet) but if it still doesn't work then I need to see what you have now.
bol
0
openaccount1Author Commented:
Hi bol,

Yes markers are working. but still map is not showing when page is first loaded. Below is the complete code. Did not include the API key though.

openaccount
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
<script src="http://maps.google.com/maps?file=api&v=1&key=" type="text/javascript"></script>
<script type="text/javascript">
    //<![CDATA[
 
latitude = 48.89364;
longitude = 2.33739;
 
function initialize() {
	if (GBrowserIsCompatible()) {
		var map = new GMap2(document.getElementById("map_canvas"));
		var bounds = new GLatLngBounds();
		map.setCenter(new GLatLng(latitude,longitude), 16);
 
		var bounds = map.getBounds();
		var southWest = bounds.getSouthWest();
		var northEast = bounds.getNorthEast();
		var lngSpan = northEast.lng() - southWest.lng();
		var latSpan = northEast.lat() - southWest.lat();
 
		function createMyMarker(point,name,html) {
			var marker = new GMarker(point);
			GEvent.addListener(marker, "click", function() {
				marker.openInfoWindowHtml(html);
			});
			return marker;
		}
 
		var mapshow = document.getElementById('markerType').value;
		
		if (mapshow==1)
		{
var markers=new Array();
markers[0] = new Array(48.89494,2.33472,"<center>Marker1</center>");
markers[1] = new Array(48.89116,2.33438,"<center>Marker2</center>");
		}
		
		if (mapshow==2)
		{
var markers=new Array();
markers[0] = new Array(48.89136,2.34532,"<center>Marker1</center>");
markers[1] = new Array(48.88851,2.34537,"<center>Marker2</center>");
markers[2] = new Array(48.89136,2.34600,"<center>Marker2</center>");
markers[3] = new Array(48.89136,2.34650,"<center>Marker2</center>");
markers[4] = new Array(48.89136,2.34700,"<center>Marker2</center>");
		}
		for (var i=0; i < markers.length; i++) {
			var lat = parseFloat(markers[i][0]);
			var lng = parseFloat(markers[i][1]);
			var point = new GLatLng(lat,lng);
			var html = markers[i][2];
			var label = "";
			var marker = createMyMarker(point,label,html);
			map.addOverlay(marker);
			bounds.extend(marker.getPoint());
		}
 
      map.setZoom(map.getBoundsZoomLevel(bounds));
      map.setCenter(bounds.getCenter());
 
		map.addControl(new GScaleControl());
		map.addControl(new GLargeMapControl());
		map.addControl(new GOverviewMapControl());
		map.addControl(new GMapTypeControl());
	}
}
    //]]>
 
    </script> 
</head>
 
<body>
  <select name="markerType" id="markerType" onchange="initialize()">
    <option value="1" selected="selected">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
  </select> 
<div class="picborder" id="map_canvas" style="width: 600px; height: 500px"></div>
</body>
</html>

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0
b0lsc0ttIT ManagerCommented:
Your body tag doesn't have the script it needs so the Map is loaded when the page loads.  Modify your body tag so it is like the one in the snippet and that should fix this.
bol

<body onLoad="initialize()" onUnload="GUnload()">

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0
openaccount1Author Commented:
Excellent its working correctly now.
0
openaccount1Author Commented:
Excellent solution. gave me everything I need.
0
b0lsc0ttIT ManagerCommented:
Great!  I am glad I could help.  Thanks for the grade, the points and the fun question.
bol
0
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