posted 09-22-2014 07:09 PM ET (US)        

The GPX website suggests that GPX output can and should be validated for conformance to the GPX XML specification. The method suggested is to use the XML Parser XERCES. See

http://www.topografix.com/gpx_validation.asp

Installing XERCES for MacOS 10.6.8 required compiling a binary from the source distribution. This was greatly facilitated by a note from another user who found an important change that must be made in the process. See the instructions under the heading "1 Answer" at

http://stackoverflow.com/questions/17102409/ mac-osx-compatibility-version-of-xerces-c-dylib-10-5-10-8

I compiled XERCES from

/Users/jimh/xerces/xerces-c-3.1.1/

and then tested it by running the SAXcount utility against a sample file:


bigDog:xerces-c-3.1.1 jimh$ cd samples/data/
bigDog:data jimh$ SAXCount -v=always personal.xml
personal.xml: 1 ms (37 elems, 12 attrs, 134 spaces, 134 chars)


This output indicated a valid XML file. Then I tested a typical GPX file I had created from data on my chart plotter during a long cruise (to Isle Royale National Park in 2013):


bigDog:data jimh$ SAXCount -v=always -n -f IRNP2013TrackOnly.gpx


The output was very long and contained a list of errors. Here are some examples:


Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 2, char 90
Message: no declaration found for element 'gpx'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 2, char 90
Message: attribute 'xmlns' is not declared for element 'gpx'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 2, char 90
Message: attribute 'version' is not declared for element 'gpx'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 2, char 90
Message: attribute 'creator' is not declared for element 'gpx'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 3, char 15
Message: no declaration found for element 'metadata'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 4, char 15
Message: no declaration found for element 'time'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 5, char 21
Message: no declaration found for element 'depthunits'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 6, char 20
Message: no declaration found for element 'tempunits'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 7, char 19
Message: no declaration found for element 'sogunits'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 10, char 10
Message: no declaration found for element 'trk'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 11, char 15
Message: no declaration found for element 'name'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 12, char 17
Message: no declaration found for element 'trkseg'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 13, char 58
Message: no declaration found for element 'trkpt'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 13, char 58
Message: attribute 'lon' is not declared for element 'trkpt'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 13, char 58
Message: attribute 'lat' is not declared for element 'trkpt'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 14, char 23
Message: no declaration found for element 'time'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 15, char 28
Message: no declaration found for element 'watertemp'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 16, char 22
Message: no declaration found for element 'sog'

Error at file /Users/jimh/xerces/xerces-c-3.1.1/samples/data/IRNP2013TrackOnly.gpx, line 18, char 58
Message: no declaration found for element 'trkpt'


As you can see, something is very wrong. The parser complains about every line in the file. Any XML, XERCES, or GPX experts out there that can help?

posted 09-23-2014 12:43 AM ET (US)            

quote:

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Not sure what you are trying to accomplish...

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I am trying to validate a GPX file I created. I use an XML parser called XERCES that I compiled from the source code on my MacOS 10.6.8 machine. The XERCES package compiled and installed without error, and the utility SAXcount runs fine on the sample XML file. When I run SAXcount against my GPX file, the parser finds hundreds of errors.

Complicating the testing of my installation: the sample GPX files on the GPX website are no longer available; they're all dead links.

I think the compiled package I installed is working. I am trying to figure out if if my GPX files are really not valid or if there is something awry with my XERCES installation.

acseatsri says:

quote:

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...I convert Lowrance & Humminbird tracks and coordinates back and forth using GpsBabel without any fuss.

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