[x3d-public] MFString in python x3d.py

Wed Jul 19 12:04:35 PDT 2023

I have many changes to contribute to x3d.py JSON output.  I would not get
carried away without my changes!

I have the whole head statement worked out right now.  I have not had to
make many changes to x3djson.py.

Be aware that I spent a lot of time getting the Comment class working, at
least initially, and I have a JSONListHelper function, which makes it easy
to sort through children, I hope

On Wed, Jul 19, 2023 at 8:31 AM Brutzman, Donald (Don) (CIV) <
brutzman at nps.edu> wrote:

> Thanks for tackling one of the hardest issues John.  Thanks for spot-on
> analysis Vince.
>
>
>
> Recommendations to keep in mind:
>
>    1. Be very precise about your use of single-quote and double-quote
>    characters.  Then your output is simple and correct.
>    2. Slightly different handling rules for SFString and MFString values,
>    based on Python [ list ] square brackets.
>    3. Utility methods in x3d.py permit substituting a simple string for
>    an MFString, but you have to be careful not to smash a list into a single
>    value (as Vince points out).
>
>
>
> Excerpt from
>
>    - *X3D Example Archives: X3D4WA, X3D for Web Authors, Chapter 04
>    Viewing Navigation, Navigation Info Example*
>    -
>    https://www.x3dgraphics.com/examples/X3dForWebAuthors/Chapter04ViewingNavigation/NavigationInfoExampleIndex.html
>    -
>    https://www.x3dgraphics.com/examples/X3dForWebAuthors/Chapter04ViewingNavigation/NavigationInfoExample.py
>
>
>
> Suggested python encoding excerpted with highlights, autogenerated:
>
>
>
>                # […]
>
>
>
>   Scene=Scene(
>
>     #  Because these NavigationInfo nodes are here in the parent scene,
> the first one is bound at load time, and thus governs the active navigation
> modes
>
>     #  Note that an author can control what choices a user has available,
> and initial type selected, while the user can select among navigation
> choices from available options
>
>     #  Author TODO: Experiment by swapping order of these NavigationInfo
> nodes, first one is bound at load time
>
>     children=[
>
>     WorldInfo(title='NavigationInfo.x3d'),
>
>     NavigationInfo(DEF='DEFAULT_EXAMINE_FIRST'),
>
>     NavigationInfo(DEF='FLY_FIRST',type=*'"FLY" "ANY"'*),
>
>     NavigationInfo(DEF='SIT_TIGHT',type='"NONE"'),
>
>     #  Also note that this scene does not provide a way to select a
> different NavigationInfo node during run time
>
>     Inline(url=["../HelloWorld.x3d",
> https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/HelloWorld.x3d
> ,"../HelloWorld.wrl",*https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/HelloWorld.wrl
> <https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/HelloWorld.wrl>*
> ])])
>
> ) # X3D model complete
>
>
>
> Checking on compilation and execution during unit tests:
>
>
>
>    -
>    https://sourceforge.net/p/x3d/code/HEAD/tree/www.web3d.org/x3d/content/examples/build.python.all.log.txt
>
>
>
> ===================================
>
> create python:
>
> C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors/Chapter04ViewingNavigation//NavigationInfoExample.x3d
> processing with X3dToPython stylesheet...
>
> C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors/Chapter04ViewingNavigation//NavigationInfoExample.py
> self-validation tests...
>
> validate python:
>
> x3d.py package 4.0.64.0 loaded, have fun with X3D Graphics!
>
> Self-test diagnostics for NavigationInfoExample.py:
>
> meta info: Contained Inline scene has profile Immersive
>
> Python-to-XML well-formed XML document  test of XML output complete
>
> Python-to-XML X3D 3.3 schema validation test of XML output complete
>
> Python-to-VRML export of VRML output successful
>
> Python-to-JSON export of JSON output successful (under development)
>
> python NavigationInfoExample.py load and self-test diagnostics complete.
>
> ===================================
>
>
>
> However am seeing two errors:
>
>
>
>    1. Looks like the example excerpt is helpful but also has two mistakes:
>
>
>
>    - NavigationInfo(DEF='FLY_FIRST',type='"FLY" "ANY"'),
>
> should be
>
>    - NavigationInfo(DEF='FLY_FIRST',type=["FLY","ANY"]),
>
>
>
>    - Last value in url MFString list is *unquoted* (scroll way-way-way to
>    the right to find it)
>
>
>
> I will work on the *X3dToPython.xslt* conversion stylesheet to address
> these two conversion errors (be patient please).
>
>
>
> 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
> https://faculty.nps.edu/brutzman
>
>
>
> -----Original Message-----
> From: x3d-public <x3d-public-bounces at web3d.org> On Behalf Of Vincent
> Marchetti
> Sent: Wednesday, July 19, 2023 5:48 AM
> To: John Carlson <yottzumm at gmail.com>; X3D-Public <x3d-public at web3d.org>
> Subject: Re: [x3d-public] MFString in python x3d.py
>
>
>
> > On Jul 19, 2023, at 5:40 AM, John Carlson <yottzumm at gmail.com> wrote:
>
> >
>
> > First off, I realize x3d.py JSON is under development.
>
> >
>
> > I'm trying to output an MFString to JSON in x3d.py and I'm kind of
> stuck?  I've been modifying x3d.py to JSON output, but I've spent way too
> much time on it and it's dang frustrating.
>
> >
>
> > I have the code:
>
> >
>
> > ImageTexture(url=["images/X3dJavaSceneAccessInterfaceSaiLibrary.png","
>
> > http://www.web3d.org/specifications/java/examples/images/X3dJavaSceneA
>
> > ccessInterfaceSaiLibrary.png"])
>
> >
>
> > Don has:
>
> >
>
> > ImageTexture(url=["images/X3dJavaSceneAccessInterfaceSaiLibrary.png","
>
> > http://www.web3d.org/specifications/java/examples/images/X3dJavaSceneA
>
> > ccessInterfaceSaiLibrary.png"])
>
> >
>
>
>
> Yes, those two declarations of the ImageTexture node are the same.
>
> Can you show what the resulting json encoding of this node is, and what
> problems are occurring with that encoding?
>
>
>
> > The same, right?
>
> >
>
> > I'm wondering if I should try this approach:
>
> >
>
> > NavigationInfo(type="\"EXAMINE\" \"FLY\" \"ANY\""),
>
> >
>
>
>
> I would recommend against this.
>
>
>
> This approach is mixing up the details of several different encodings at
> once.
>
>
>
> The expression you have there, in particular the \" constructions, is
> going to be interpreted according to the rules of the Python Lexical parser
> https://docs.python.org/3/reference/lexical_analysis.html#string-and-bytes-literals
>
> and, if done just right, gives you the single python string with value
> "EXAMINE""FLY""ANY"
>
> This string only works as to represent an MFString value, when used to
> form an XML attribute in the XML encoding of X3D. It has little to do with
> json.
>
>
>
> > John
>
> >
>
>
>
> Vince Marchetti
>
> _______________________________________________
>
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>
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>
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>
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