Question

I am trying to create a KML file dynamically in C#. I have wrote a recursive function to do this. However the result of output has a bit problem. The problem is the position of closing tags of all placemarks. I am really confused. Please tell me where am I making mistake in the recursive function???

My code:

private void xmlBuild()
    {
XDocument doc = new XDocument(
        new XDeclaration("1.0", "utf-8", ""),
        new XComment("This is comment by me"),
        new XElement(ns+"kml", 
        new XElement(ns+"Document", rec_build())));      
        doc.Save(Server.MapPath(@"~\App_Data\markers2.xml"));
}
private XElement rec_build()
    {
        if (iteration != 0)
        {
            iteration -= 1;
            return final_rec = new XElement(ns + "Placemark",
                    new XAttribute("id", "1"),
                    new XElement(ns + "title", "something"),
                    new XElement(ns + "description", "something"),
                    new XElement(ns + "LookAt",
                    new XElement(ns + "Longitude", "49.69"),
                    new XElement(ns + "Latitude", "32.345")), new XElement(ns + "Point", new XElement(ns + "coordinates", "49.69,32.345,0")),rec_build());
        }
        else
        {
            return null;
        }
    }

and this is the output for iteration value of 2: (please notice the closing tags of placemark id=1 at the end of file. It should be before the starting tag of placemark id=2!

<?xml version="1.0" encoding="utf-8"?>
<!--This is comment by me-->
<kml xmlns="http://earth.google.com/kml/2.2">
  <Document>
    <Placemark id="1">
      <title>something</title>
      <description>something</description>
      <LookAt>
        <Longitude>49.69</Longitude>
        <Latitude>32.345</Latitude>
      </LookAt>
      <Point>
        <coordinates>49.69,32.345,0</coordinates>
      </Point>
      <Placemark id="1">
        <title>something</title>
        <description>something</description>
        <LookAt>
          <Longitude>49.69</Longitude>
          <Latitude>32.345</Latitude>
        </LookAt>
        <Point>
          <coordinates>49.69,32.345,0</coordinates>
        </Point>
      </Placemark>
    </Placemark>
  </Document>
</kml>

Answer 1

So the problem is each time you recurse, you are adding the element to the newly created item. It seems that a loop would work better.

Essentially code is doing this:

set up the kml outbody
1st call and add element (element 1) to kml outerboy
2nd call add element (element 2) to (element 1)
3rd call add element (element 3) to (element 2).

If you wanted to do a recursive method rather then the looping mechanism, pass in a reference to the outer kml .

The recursive is more confusing if this is exactly how it works

(Sorry if I have an extra or missing parenthesis, comma, or other item. I don’t have VS installed on this)

Looping:

private void xmlBuild()
{
    XElement documentElement = new XElement(ns + "Document");

    for (int i = 0; i < 2; i++)
    {
        documentElement.Add(rec_build());
    }

    XDocument doc = new XDocument(
        new XDeclaration("1.0", "utf-8", ""),
        new XComment("This is comment by me"),
        new XElement(ns + "kml", documentElement));

    doc.Save(Server.MapPath(@"~\App_Data\markers2.xml"));
}

private XElement rec_build()
{

    return new XElement(ns + "Placemark",
           new XAttribute("id", "1"),
           new XElement(ns + "title", "something"),
           new XElement(ns + "description", "something"),
           new XElement(ns + "LookAt",
           new XElement(ns + "Longitude", "49.69"),
           new XElement(ns + "Latitude", "32.345")), 
           new XElement(ns + "Point", 
           new XElement(ns + "coordinates", "49.69,32.345,0")));
}

Recursive:

private void xmlBuild()
{
    XElement docElement = new XElement(ns+"Document");
    rec_build(docElement);
    XDocument doc = new XDocument(
    new XDeclaration("1.0", "utf-8", ""),
    new XComment("This is comment by me"),
    new XElement(ns+"kml", docElement)));      
    doc.Save(Server.MapPath(@"~\App_Data\markers2.xml"));
}
private XElement rec_build(XElement doc)
{
    if (iteration != 0)
    {
        iteration -= 1;
        doc.Add(new XElement(ns + "Placemark",
                new XAttribute("id", "1"),
                new XElement(ns + "title", "something"),
                new XElement(ns + "description", "something"),
                new XElement(ns + "LookAt",
                new XElement(ns + "Longitude", "49.69"),
                new XElement(ns + "Latitude", "32.345")), 
                new XElement(ns + "Point", new XElement(ns + "coordinates", "49.69,32.345,0")));
        return recBuild(doc);
    }
    else
    {
        return null;
    }
}