Hacking Google Maps and Google Earth (ExtremeTech)

Chapter 16 — Generating Google Earth Feeds 321

<?xml version=”1.0” encoding=”UTF-8”?>

<kml xmlns=”http://earth.google.com/kml/2.0”>

<Document>

<visiblity>1</visbility>

<NetworkLink>

<name>ExtremeTech Google Maps: Grantham Entities</name>

<Url>

<href>http://maps.mcslp.com/examples/ch16-03.cgi</href>

<refreshMode>onInterval</refreshMode>

<refreshInterval>300</refreshInterval>

<viewRefreshMode>onStop</viewRefreshMode>

<viewRefreshTime>7</viewRefreshTime>

</Url>

</NetworkLink>

</Document>

</kml>

Looking at the individual elements, you can pick out the main points. First, you define the

name of the network link:

<name>ExtremeTech Google Maps: Grantham Entities</name>

Then you specify the URL, the refresh mode, the interval (specified in seconds), and the view-

ing format. Open the KML file in Google Earth, and the dynamic KML will automatically be

loaded.

Adding Icons

You can stylize a <Placemark>tag with a custom icon by using the Styleelement. The

Styleelement enables you to set custom styles for a <Placemark>tag. The IconStyle

element defines the icon details. For example:

<Style>

<IconStyle>

<Icon>

<href>http://maps.mcslp.com/examples/bank.png</href>

</Icon>

</IconStyle>

</Style>

The <href>element defines the location of the icon graphic. In this case, the location speci-

fied is the same as that used for the Bank icon example demonstrated in Chapter 11. You can

use a single source file for the icon and extract the icon using the x/y reference of the left/bot-

tom edge and the height and width of the icon (using the <h>and <w>tags).

For the final example, you’ll use a simple icon, chosen using the type name to generate the

icon, just as used in Chapter 11. The resulting script is shown as follows: