David Faiz David Faiz - 18 days ago 13
HTML Question

Jquery '$' is undefined

I have created the webpage below and successfully ran it on several machines.
When I run it on another machine it fails. When debugging it this error: Error: '$' is undefined

Running on IE 9.

I have tried to change the Jquery link to:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>


but it didn't help.
What can be the reason for the error ?

There is the complete code:

<!DOCTYPE html>
<html>
<head>
<title>Simple Map</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<META HTTP-EQUIV="Refresh" CONTENT="420">
<style type="text/css">
html, body, #map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}


.labels {
color: orange;
background-color: black;
font-family: "Lucida Grande", "Arial", sans-serif;
font-size: 10px;
font-weight: bold;
text-align: center;
width: 50px;
border: 2px solid black;
white-space: nowrap;}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="https://jquery-xml2json-plugin.googlecode.com/svn/trunk/jquery.xml2json.js" type="text/javascript" language="javascript"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
<script src="http://google-maps-utility-library-v3.googlecode.com/svn/tags/markerwithlabel/1.0.1/src/markerwithlabel.js"></script>
<script>
var markers = [];
var map = null;

$.get('Customers.xml', function(xml) {
var jsonObj = $.xml2json(xml);
$.each(jsonObj.Marker, function(){
var stat = this.site_status == "Critical" ? "http://maps.google.com/mapfiles/ms/micons/red-dot.png" : "http://maps.google.com/mapfiles/ms/micons/green-dot.png";
var mark = {
title: this.title,
location: this.site_location,
icon: stat
}
markers.push(mark);
});
for(var i=0; i< markers.length; i++){
var maddress = markers[i].location;
var image = markers[i].icon;
var custname = markers[i].title;
geocodeAddress(maddress, image, custname,map);
}
});

function geocodeAddress(maddress, image, custname,map) {
var geocoder = new google.maps.Geocoder();
geocoder.geocode( { 'address': maddress}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var myLatlng = new google.maps.LatLng(results[0].geometry.location.lat(),results[0].geometry.location.lng());
var iconBase = 'https://maps.google.com/mapfiles/kml/shapes/';
var marker = new MarkerWithLabel({
position: myLatlng, map:map, icon: image,labelContent: custname,
labelAnchor: new google.maps.Point(22, 0),
labelClass: "labels", // the CSS class for the label
labelStyle: {opacity: 0.75}});
} else {
alert("Geocode was not successful for the following reason: " + status);
}
});
}

function initialize() {
var chicago = new google.maps.LatLng(35.442579,-40.895920);
var mapOptions = {
zoom: 4,
center: chicago,
mapTypeId: google.maps.MapTypeId.ROADMAP
}

map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<div id="map-canvas"></div>
</body>
</html>


Thanks in advance.

Answer

The function $ is held within the script :

//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js

So even calling $(function() { ... or $(document).ready( ... before this script has loaded will both result in $ being undefined

As your load order of the scripts looks correct, it appears like you are not able to load the jquery.min file - try clicking this link from the machine with the problem to make sure

And /or ( and not to spark a CDN vrs Local debate ) - download the jquery file and call it locally (what if your visitor could not see the file for other reasons? ) - at teh very least have a back up plan.

<script src="/pathtojsfiles/jquery.min.js"></script>

as an aside, a better ( loading your markup that that scripts are going to use ) document setup would be to place the scripts and your functions using these scripts under the markup, before the closing </body> tag. This ( for more SEO related websites ) will ensure your page contents are loaded before you add external JS.

! - This looks already said by some of these answers popping in as a type, but posting anyway ..