Re: [xml-dev] KML is very extensible ... but why?

On Sun, 22 Apr 2018, 14:29 Simon St.Laurent, <simonstl@simonstl.com> wrote:

On 4/20/2018 12:59 PM, Costello, Roger L. wrote:

Hi Folks,

The format of KML 2.3 documents are specified with a W3C 1.1 XML Schema. XML Schema 1.1 has a powerful feature which KML uses. At the top of the KML schema is this:

<defaultOpenContent mode="interleave">
<any namespace="##other" processContents="lax"/>
</defaultOpenContent>

Read as: "KML documents are open. That is, XML elements from any non-KML namespace can be inserted before and after every element in KML documents. Those non-KML elements do not have to validate against any schema."

That makes KML very extensible.

But why?

Why not? In Simon's world of sane XML, EVERY SINGLE SCHEMA would include such a thing, and be mocked if it didn't.

And in RDF, it comes with the territory; you have to work harder to escape the flexibility and extensibility. It has been a blessing ans a curse :)

Thanks,
Simon

If I add non-KML stuff in a KML instance, who’s going to understand my stuff? Google Earth? No. Google Maps? No. NASA WorldWind? No.

Only applications that have been custom-coded to understand my stuff will be able to do anything with it. Right? Doesn’t that destroy KML as a global geographic annotation/visualization language since now you’ve got all these non-interoperable dialects floating around?

Thoughts?

/Roger