[gdal-dev] Logics of CPLGetXMLValue and CPLFetchBool

[Ari Jolma]

I thought it would be perhaps good to have CPLGetXMLBoolean since we 
have CPLFetchBool and many of the option values needed by the new WCS 
driver are boolean flags and the option values end up in the service 
XML. It would twist the brain a bit less if one could simply use 
CPLGetXMLBoolean.

The logic of CPLFetchBool is that it is true if a key exists but is not 
defined or if the value is not something considered untrue ('NO', etc). 
The logic of CPLGetXMLValue is that it returns the given default in the 
case the element/attribute is not found or if it is found but is empty, 
i.e., not defined.

Thus the return value of CPLGetXMLBoolean can't use CPLGetXMLValue if it 
follows the logic of CPLFetchBool. That is true is existence and no denial.

What say?

Ari