[X3D-Ecosystem] Using prantlf/jsonlint with “X3D” JSON schema; current capabilities

[John Carlson]

Note that CPPON doesn’t currently have a node list/factory pattern.
Contributors are welcome!

On Sun, Jan 4, 2026 at 12:39 PM John Carlson <yottzumm at gmail.com> wrote:

> I would love to contribute to the JSON standard now that I am a member
> again.  I just don’t know about my wordsmithing skills, so people will have
> to improve what I write.
>
> The feature I am showing in @prantlf/jsonlint is the ability to use JSON
> schema.  Other jsonlint’s I am aware of do not use JSON schema, so they are
> simply like JSON.parse() in JavaScript with error reporting.   What this
> means is if you have a node that isn’t an X3D node in JSON, no error will
> be reported, possibly leading to constructors that weren’t meant to be
> called, like Function, to name a potentially dangerous one.  Recent code
> related to Maya was revealed to access globals() to construct a class.
>
> This is why JSON Schema, XML schema (on JSON), a factory pattern, a set of
> node names to check against, an API like X_ITE, X3DOM, X3DJSAIL or Castle
> is of upmost concern, in mildly conservative cases.  APIs can have a wide
> variety of treatment, with eval being common in some, it’s not wise to just
> use a linter.
>
> I welcome Altova XMLSpy and Liquid XML.  OxygenXML might be another.  Some
> have more means than others.   XML schema can be employed for those who
> can’t afford a commercial schema and don’t want to use my JSON schema.   I
> recommend web3d invest in the XML schema solution for JSON documents before
> proceeding with JSON Schema, realizing JSON schema has things that XML
> schema doesn’t and vica versa.  I have also investigated other XML schema
> to JSON schema solutions, and X3D JSON appears to be a special case.
>
> There’s no problem with just typing constructors hardcoded in your Java
> code, that’s validated by the compiler/interpreter.  The problem is
> treating data like code.
>
> Thanks,
>
> John
>
> On Sun, Jan 4, 2026 at 11:30 AM Don Brutzman <don.brutzman at gmail.com>
> wrote:
>
>> First off, for clarity, there is no official X3D JSON Schema yet.
>>
>> Next, the X3D Example Archives provide a jsonlint link via jsonlint.com
>> for each of the models.  For instance,
>>
>>    - X3D Example Archives: X3D4WA, X3D for Web Authors, Chapter 03
>>    Grouping, Group Animated
>>    - Example for Group node, with animated color for the Sphere
>>    -
>>    https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter03Grouping/GroupAnimatedIndex.html
>>    - " .json
>>    <https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter03Grouping/GroupAnimated.json>
>>     (check
>>    <https://jsonlint.com/?url=https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter03Grouping/GroupAnimated.json>
>>    ) " (see blue highlight in image)
>>    -
>>    https://jsonlint.com/?url=https://www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter03Grouping/GroupAnimated.json
>>    - " JSON is valid!  "
>>
>> [image: image.png]
>>
>> The build scripts for the example archives also use
>>
>>    - Google Code Archive: jslint4java
>>    - https://code.google.com/archive/p/jslint4java/
>>    - example console output:
>>
>> C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors/Chapter03Grouping//GroupAnimated.json
>>> validation checking with jslint
>>> C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors/Chapter03Grouping//GroupAnimated.json
>>> validation checking with json-schema-validator
>>> ... does not support latest JSON Schema, this test is not yet usable
>>
>>
>> So I think we have good coverage of jsonlint for the examples archive.
>>
>> Our best description for how to use X3D JSON can be found at
>>
>>    - *X3D to JSON Stylesheet Converter*
>>    - The X3D to JSON stylesheet converts .x3d XML to .json, supporting
>>    the forthcoming JSON Encoding for X3D Graphics.
>>    - https://www.web3d.org/x3d/stylesheets/X3dToJson.html
>>
>> Next, looking ahead: later this year am expecting we will look at
>> updating and autogenerating the X3D JSON Schema from X3DUOM using best
>> practices.  Although JSON Schema was never standardized via IETF RFC, usage
>> seems fairly common these days.  This can be an informative annex in
>> upcoming X3D JSON Encoding ISO/IEC 19776-5:202x specification.  Using
>> x3d-public mailing list, am expecting we will have at least three design
>> patterns to consider:
>>
>>    1. your best effort for JSON schema
>>    2. Altova XMLSpy, XML schema converted to JSON schema
>>    3. Liquid XML, XML schema converted to JSON schema
>>    4. any other design patterns that are offered
>>
>> It certainly will be interesting to have an X3D JSON draft standard and
>> some recommendable form of X3D JSON validation available.  Thanks for
>> leading the way in this direction.
>>
>> Have fun with X3D JSON!  😀
>>
>> all the best, Don
>> --
>> X3D Graphics, Maritime Robotics, Distributed Simulation
>> Relative Motion Consulting  https://RelativeMotion.info
>>
>>
>> On Sun, Jan 4, 2026 at 6:39 AM John Carlson via X3D-Ecosystem <
>> x3d-ecosystem at web3d.org> wrote:
>>
>>> If you use jsonlint to validate JSON, you may get this error:
>>>
>>> echo "{}" | jsonlint -V x3d-4.0-JSONSchema.json -e draft-2020-12
>>>
>>> File: <stdin>
>>> Loading the JSON Schema failed:
>>> Compiling the JSON Schema failed.
>>> strict mode: unknown keyword: "x-orderOf"
>>>
>>>
>>> I have just become aware of this.
>>>
>>>
>>> X3dvalidate avoids this by passing { strict: false } to the Ajv2020 constructor.
>>>
>>>
>>> So your choices are use x3dvalidate, modify the schema, or modify jsonlint.
>>>
>>>
>>> If someone wants me to do a pull request for jsonlint, I can look into it, but I feel the ajv-formats2019 will need to be added as well.
>>>
>>>
>>> As the x-orderOf is non-functional, I can also remove it.
>>>
>>>
>>> John
>>>
>>> --
>>> X3D-Ecosystem mailing list
>>> X3D-Ecosystem at web3d.org
>>> http://web3d.org/mailman/listinfo/x3d-ecosystem_web3d.org
>>>
>>
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