[x3d-public] quotes in xml -> xhtml conversion

[Andreas Plesch]

Thanks Don,

escaping as ' avoids the parsing error. But now in the generated X3D
Scene Metadata table below the scene, the escaped apostrophe is rendered as
"'". because the html is generated as ' . This is more or
less cosmetic.

-Andreas


On Sun, Jan 24, 2016 at 2:49 AM, Don Brutzman <brutzman at nps.edu> wrote:

> cc: group due to likely general interest, hope that is OK
>
> On 1/23/2016 12:12 PM, Andreas Plesch wrote:
>
>> While cleaning up GeoLOD implementation I noticed the following.
>>
>> The Geospatial Squaw Valley example at
>>
>> http://www.web3d.org/x3d/content/examples/Basic/#Geospatial
>>
>> has double quotes surrounding the content field value of the meta node in
>> the canonical xml:
>>
>>
>> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/SquawCanonical.xml
>>
>> but has singles quotes surrounding the same field value in the xhtml:
>>
>> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.xhtml
>>
>> which leads to an unavoidable parsing error because the value string has
>> an embedded single quote.
>>
>> The safest way to deal with embedded quotes may be to escape them (&quot)
>> but I am not sure. Keeping the surrounding quotes as double quotes may also
>> work but then it is necessary to escape embedded double quotes (which may
>> more rarely occur).
>>
>
> Thanks for your error report Andreas.  Just to be sure, I think you are
> talking about the following tag:
>
>     <meta content='This model was output using the GeoVRML export
> capabilities of ESRI's 3D Analyst Extension for ArcView/ArcInfo 8.1
> product (official release date Q1 2001). This example is created by
> combining an ortho image (retouched to have a blue color) with a DEM of the
> squaw valley, near Lake Tahoe. Coordinates are UTM.' name='description'/>
>
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.xhtml
> (pretty print)
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.xhtml
> (problem version)
>
> I typically use apostrophes for attribute='value' definitions to simplify
> handling of quote marks.
>
> Incidentally, ' and " are always safe in HTML  as part of
> attribute content, regardless of whether apostrophes or quote marks are
> used to contain that data.
> http://www.web3d.org/x3d/content/examples/X3dSceneAuthoringHints.html#HTML
>
> More on this topic can be found in _X3D for Web Authors_ and the following
> links.
> - corresponding slideset, under Thttp://
> x3dgraphics.com/slidesets/X3dForWebAuthors/Chapter02-GeometryPrimitives.pdf
>   especially slides 25-27
> -
> http://x3dgraphics.com/examples/X3dForWebAuthors/Chapter02-GeometryPrimitives/#TextSpecialCharacters
> - X3D-Edit usually handles all such conversions for the author.
>
> As it turns out, "user agents" (a fancy spec term for software tools) are
> allowed to use either apostrophe or quote-mark pairs for attribute values -
> the resulting XML document does not have to match the original author's XML
> document in this respect.
>
> I try to apply things consistently and get these right when converting to
> X3D Canonical, pretty-print HTML, X3D Tidy etc.
>
> Looks OK:
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.x3d
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.html
>
> Aha, failure confirmed (earlier version):
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.xhtml
> ======================================================================
> XML Parsing Error: not well-formed Location:
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.xhtml
> Line Number 213, Column 84:
> <meta content='This model was output using the GeoVRML export capabilities
> of ESRI's 3D Analyst Extension for ArcView/ArcInfo 8.1 product - etc.'
> name='description'/>
>
> -----------------------------------------------------------------------------------^
> ======================================================================
>
> took a little bit of doing but i think that attribute values are better
> escaped now.  corrected test-output copy attached for archives, this online
> link is working now.
>
> ... Corrected versions of all Geospatial example .xhtml versions are now
> refreshed online, hope that helps your continued testing and improvements
> for X3DOM.  i will run the improved stylesheet on all example scenes and
> upload the .xhtml X3DOM versions next week.
> http://www.web3d.org/x3d/content/examples/Basic/Geospatial
>
> Also updated the internal list of supported nodes in X3dToX3dom.xslt
> stylesheet to match the current list at
> http://doc.x3dom.org/author/nodes.html
>
> There were also some overzealous diagnostics in the X3D Validator and X3D
> DTD for this geospatial scene... most improvements complete.
>
> https://savage.nps.edu/X3dValidator?url=http://www.web3d.org/x3d/content/examples/Basic/Geospatial/Squaw.x3d
>
> The Squaw valley scene examples are curious because they came from an old
> ESRI tool, and because it only uses one of 4 quad urls in each GeoLOD.
> Probably ought to be improved.
>
> Again thanks for reporting this deficiency.
>
> all the best, Don
> --
> Don Brutzman  Naval Postgraduate School, Code USW/Br
> brutzman at nps.edu
> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA
> +1.831.656.2149
> X3D graphics, virtual worlds, navy robotics
> http://faculty.nps.edu/brutzman
>



-- 
Andreas Plesch
39 Barbara Rd.
Waltham, MA 02453
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