Re: [georss] was KML into OGC now KML into W3C?

Sean Gillies wrote:

>Mike Liebhold wrote:
>  
>
>>Carl Reed wrote:
>>
>>"KML is fundamentally focused on Geographic Visualization - meaning 
>>visualization of places on the earth - and annotating or describing 
>>places. "
>>
>>Carl and epecially Josh
>>
>>Another question:
>>Given that KML annotation -documents-  are more web-like than 
>>geographic, but strangely constrained;  Shouldn't Google be invited to 
>>submit at least those portions of KML  for  W3C  review and 
>>standardization process?
>>
>>    
>>
>
>Good question. Why not W3C?
>
>Cheers,
>Sean
>
>  
>

Thanks, Sean,  for raising the issue again regarding w3C consideration 
of KML placemark documents, 

Ideally a geobrowser like Google Earth would simply ingest and render 
-any- georss annotated web objects, but so far they are taking much more 
limited approach:

Here are some of the portions of KML in question that might be of 
interest to W3C xg-geo: from

http://earth.google.com/kml/kml_tut.html#placemarks

[snip]


      Placemarks

A Placemark is one of the most commonly used features in Google Earth. 
It marks a position on the Earth's surface, using a yellow pushpin as 
the icon. The simplest Placemark includes only a <Point> element, which 
specifies the location of the Placemark. You can specify a name and a 
custom icon for the Placemark, and you can also add other geometry 
elements to it.

Open the KML Samples 
<http://code.google.com/apis/kml/documentation/KML_Samples.kml> file in 
Google Earth and expand the Placemarks subfolder. This folder includes 
three different types of placemark: /simple/, /floating/, and 
/extruded/. The KML code for the simple placemark looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
  <Placemark>
    <name>Simple placemark</name>
    <description>Attached to the ground. Intelligently places itself 
       at the height of the underlying terrain.</description>
    <Point>
      <coordinates>-122.0822035425683,37.42228990140251,0</coordinates>
    </Point>
  </Placemark>
</kml>

The structure of this file breaks down as follows:

    * An XML header. This is line 1 in every KML file. No spaces or
      other characters can appear before this line.
    * A KML namespace declaration. This is line 2 in every KML 2.1 file.
    * A Placemark object that contains the following elements:
          o - A /name/ that is used as the label for the Placemark
          o - A /description /that appears in the "balloon" attached to
            the Placemark
          o - A /Point/ that specifies the position of the Placemark on
            the Earth's surface (/longitude, latitude,/ and optional
            /altitude/)

If you were wondering where the Placemark is, it's right over Google's 
Building 41, where we developed Google Earth!

What users commonly think of as a "placemark" in Google Earth is 
actually a <Placemark> element with a <Point> child in KML. A Point 
Placemark is the only way to draw an icon and label in the 3D Viewer of 
Google Earth. By default, the icon is the familiar yellow pushpin. In 
KML, a <Placemark> can contain one or more geometry elements, such as a 
LineString, Polygon, or Model. But only a <Placemark> with a Point can 
have an icon and label. The Point is used to place the icon, but there 
is no graphical representation of the Point itself.


      Descriptive HTML in Placemarks

The KML Samples 
<http://code.google.com/apis/kml/documentation/KML_Samples.kml> file has 
an example of almost everything you can do with Placemark text. You can 
add links, font sizes, styles, and colors, and specify text alignment 
and tables. If you'd like to see the full list, copy and paste the 
"Descriptive HTML" Placemark example (in the Styles and Markup folder) 
into a text editor.


        Auto-Markup in Google Earth (Release 4.0 and later)

Google Earth 4.0 has an auto-markup feature that automatically converts 
text such as /www.google.com/ into active hyperlinks that the user can 
click. Text inside the <description> tag, the <Snippet> tag, and the 
<text> element of <BalloonStyle> are all automatically transformed into 
standard HTTP hyperlinks. You don't need to add the <a href= ...> tags 
yourself.


        Using the CDATA Element

If you want to write standard HTML inside a <description> tag, you can 
put it inside a CDATA tag. If you don't, the angle brackets need to be 
written as entity references to prevent Google Earth from parsing the 
HTML incorrectly (for example, the symbol *>* is written as *&gt;* and 
the symbol *<* is written as *&lt;*). This is a standard feature of XML 
and is not unique to Google Earth.

Consider the difference between HTML markup with CDATA tags and without 
CDATA. First, here's the <description> with CDATA tags:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
  <Document>
    <Placemark>
      <name>CDATA example</name>
      <description>
        <![CDATA[
          <h1>CDATA Tags are useful!</h1>
          <p><font color="red">Text is <i>more readable</i> and 
          <b>easier to write</b> when you can avoid using entity 
          references.</font></p>
        ]]>
      </description>
      <Point>
        <coordinates>102.595626,14.996729</coordinates>
      </Point>
    </Placemark>
  </Document>
</kml>

And here's the <description> without CDATA tags, so that special 
characters must use entity references:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
  <Document>
    <Placemark>
      <name>Entity references example</name>
      <description>
	        &lt;h1&gt;Entity references are hard to type!&lt;/h1&gt;
	        &lt;p&gt;&lt;font color="green"&gt;Text is 
          &lt;i&gt;more readable&lt;/i&gt; 
          and &lt;b&gt;easier to write&lt;/b&gt; 
          when you can avoid using entity references.&lt;/font&gt;&lt;/p&gt;
      </description>
      <Point>
        <coordinates>102.594411,14.998518</coordinates>
      </Point>
    </Placemark>
  </Document>
</kml>

[snip]