The network link in Google Earth isn't parsing the .Kml file for data updates?

Question

Question :

• why google earth doesn't load .kml file using network link ?

Objective:

• loading periodically positional data from a continuously updated .kml file from the hard drive (simulated data) , this kml file is generated from a python script (for use by Google earth )

Environment :

• Windows 7 . Both files (The python file and the .kml files are both on the hard drive). I am not using any remotely located information

What's done :

KML file:

 The KML file:
    <?xml version="1.0" encoding="UTF-8"?>
    <kml xmlns="http://www.opengis.net/kml/2.2">
      <Folder>
        <name>Network Links</name>
        <visibility>0</visibility>
        <open>0</open>
        <description>Network link for FPG </description>
        <NetworkLink>
          <name> NTFPG </name>
          <visibility>0</visibility>
          <open>0</open>
          <description>  The flight path generator </description>
          <refreshVisibility>0</refreshVisibility>
          <flyToView>0</flyToView>
          <Url>
            <href>viewCenteredPlacemark.py</href>

          </Url>
        </NetworkLink>
      </Folder>
    </kml>

The python file :

#!/usr/bin/python

kml = ( 
   '<?xml version="1.0" encoding="UTF-8"?>\n'
   '<kml xmlns="http://www.opengis.net/kml/2.2">\n'
   '<Placemark>\n'
   '<name>Flight Path Generator</name>\n'
   '<Point>\n'
   '<coordinates>%.6f,%.6f</coordinates>\n'
   '</Point>\n'
   '</Placemark>\n'
   '</kml>'
   ) %(-77.864,38.4556)

print 'Content-Type: application/vnd.google-earth.kml+xml\n'
print kml

I would like just to show the same position and see the GREEN dot on the network link, but it is RED , so clearly there is no parsing, whether that be due to the format of the KML file or something else. What am i missing ?

Answer 1

If want the script to be executed in which it will generate KML, the script must be hosted by a web server (e.g. Apache).

If you access the python script locally from the file system without any web server involved then Google Earth will attempt to fetch viewCenteredPlacemark.py file as a KML text file and not execute it as a python script. This will not be parsed as KML and nothing will be displayed. If turn on error handling in Google Earth then you will see a parse error.

Just need a light-weight web server that can invoke a python script such as Apache httpd. There are many tutorials to configure a web server to run python scripts.

Example:

• https://docs.python.org/2/howto/webservers.html
• http://httpd.apache.org/docs/current/mod/mod_cgi.html