[x3d-public] X3D JSON schema validation problems: @class and IMPORT/EXPORT attributes
John Carlson
yottzumm at gmail.com
Mon Jul 10 08:30:57 PDT 2017
Do we have an xml example of IMPORT/EXPORT mixed with Protos? I may need
to change my protoexpander.
John
On Jul 10, 2017 11:22 AM, "Don Brutzman" <brutzman at nps.edu> wrote:
> thanks for checking these.
>
> On 7/10/2017 6:17 AM, Roy Walmsley wrote:
>
>> Don,
>>
>> Agreed with John's later comment that @class is not included in JSON. In
>> fact, let's take that one step further and note that it is not included in
>> the abstract standard. Words containing the letters "class" only appear
>> four times in clause 4 of 19775-1 V3.3, and not at all in clause 7. None of
>> the instances is concerned with the "class" attribute that is included in
>> 19776-1. And looking at 19776-1, clause 4.3.6 class attribute syntax, the
>> text states:
>>
>> “The class attribute is reserved for use with XML Cascading Style Sheets
>> (see [CSS]).”
>>
>> So the class attribute is only for the XML encoding (and anything derived
>> from it). Therefore it should not appear in JSON. And it doesn't.
>>
>
> I had thought we had a Mantis issue about elevating the 'class' attribute
> to Abstract specification, and other encodings, since it seems to be
> essential to HTML5/CSS integration and we typically make all encodings
> fully symmetric in terms of expressive power.
>
> Searched but couldn't find the Mantis issue however. Perhaps I overlooked
> it and you can locate it?
>
> If not then I can post a specification comment so that the issue gets
> fully considered in Mantis as part of X3D v4 design.
>
> Now what about IMPORT and EXPORT.
>>
>> Let's look at the draft text in the working draft for ISO/IEC CD 19776-5,
>> clause 4.3.2.15 "IMPORT" property syntax. The text reads:
>>
>> “The "IMPORT" property is an optional property of the "Scene" object. It
>> is an array type, where each item is an object having the properties listed
>> in Table 4.13. The first column lists the name of the property. The second
>> column indicates whether the property is optional or required. The third
>> column lists the reference to the detailed encoding of the property.”
>>
>> Table 4.13 lists three properties "@AS" which is optional, and
>> "@importedDEF" and "@inlineDEF", both of which are required. No other
>> properties are permitted.
>>
>> The "EXPORT" property is defined in an analogous manner. Here is an
>> example from the draft standard:
>>
>> "EXPORT": [
>>
>> {
>>
>> "@AS": "myNodeAlias",
>>
>> "@localDEF": "myNode",
>>
>> }
>>
>> ]
>>
>> Why is it done like that? Because JSON recommends, and we have followed
>> this recommendation, that the property keys in any given object should not
>> be duplicated. So, any single object, like "Scene", cannot have multiple
>> IMPORT or EXPORT statements. They have to be collected together into an
>> array. Each IMPORT statement has three properties, so needs to be an object.
>>
>> Hope this helps,
>>
>> All the best,
>>
>> Roy
>>
>
> Thanks Roy. This will be good to sort out more closely. I don't think
> this draft JSON specification is entirely correct; IMPORT and EXPORT
> statements can appear multiple times and anywhere in the scene graph, not
> just with the Scene (root) element. Good practice for DEF
> readability/confirmation is to put each of them near their corresponding
> Inline node, but that isn't explicitly required.
>
> ============================================================
> ===============
> 9.2.5 IMPORT statement
> http://www.web3d.org/documents/specifications/19775-1/V3.3/
> Part01/components/networking.html#IMPORTStatement
>
> The following example illustrates the use of the IMPORT statement (Classic
> VRML encoding syntax):
>
> DEF I1 Inline {
> url "someurl.x3d"
> }
> . . .
>
> IMPORT I1.rootTransform AS I1Root
> DEF PI PositionInterpolator { ... }
> ROUTE PI.value_changed TO I1Root.set_translation
>
> ============================================================
> ===============
> 9.2.6 EXPORT statement
> http://www.web3d.org/documents/specifications/19775-1/V3.3/
> Part01/components/networking.html#EXPORTStatement
>
> The following example illustrates the use of the EXPORT statement (Classic
> VRML encoding):
>
> DEF T1 Transform {
> ...
> }
> . . .
>
> EXPORT T1 AS rootTransform
>
> ============================================================
> ===============
>
> and related links
>
> http://www.web3d.org/x3d/tooltips/X3dTooltips.html#IMPORT
> http://www.web3d.org/specifications/X3dSchemaDocumentation3.
> 3/x3d-3.3_IMPORT.html
> http://www.web3d.org/specifications/X3dDoctypeDocumentation3.3.html#IMPORT
> etc.
>
> We should probably check the encoding documents further to ensure that
> each DEF precedes IMPORT/EXPORT, just as DEF precedes USE. Or else NOTE
> that prior DEF definition is not a requirement.
>
>
> -----Original Message-----
>> From: Don Brutzman [mailto:brutzman at nps.edu]
>> Sent: 09 July 2017 23:55
>> To: Roy Walmsley <roy.walmsley at ntlworld.com>; John Carlson <
>> yottzumm at gmail.com>
>> Cc: X3D Graphics public mailing list <x3d-public at web3d.org>
>> Subject: X3D JSON schema validation problems: @class and IMPORT/EXPORT
>> attributes
>>
>> Finally getting "back up on the horse" to test JSON conversions using
>> X3dToJson.xslt (hooray!)
>>
>> Attached please find current version of X3DJSAIL output .x3d test scene,
>> plus corresponding .json version.
>>
>> Roy, it looks like there may be several omissions in the X3D JSON Schema:
>>
>> a. @class attribute (previously untested) not recognized
>>
>> b. IMPORT/EXPORT statements (previously untested) are apparently
>> expecting an array when simple attributes are provided
>>
>> { "IMPORT":
>>
>> {
>>
>> "@AS":"WorldInfoDEF2",
>>
>> "@importedDEF":"WorldInfoDEF",
>>
>> "@inlineDEF":"inlineSceneDef"
>>
>> }
>>
>> },
>>
>> { "EXPORT":
>>
>> {
>>
>> "@AS":"WorldInfoDEF3",
>>
>> "@localDEF":"WorldInfoDEF"
>>
>> }
>>
>> },
>>
>> Console output follows. Please advise, TIA.
>>
>> =====================================
>>
>> translation input: test/HelloWorldProgramOutput.x3d ..expected output:
>> test/HelloWorldProgramOutput.json Script DEF=colorTypeConversionScript
>> contains CDATA source-code text, copied as "#sourceText" using "strings"
>> mode Script DEF=MaterialModulatorScript contains CDATA source-code text,
>> copied as "#sourceText" using "strings" mode ..error checking with jslint
>> jslint:test/HelloWorldProgramOutput.json:447:1:JavaScript URL.
>>
>> jslint:test/HelloWorldProgramOutput.json:812:1:JavaScript URL.
>>
>> Java Result: 1
>>
>> ..error checking with json-schema-validator
>>
>> --- BEGIN C:\x3d-code\www.web3d.org\x3d\stylesheets\test\HelloWorldPro
>> gramOutput.json---
>>
>> validation: FAILURE
>>
>> [ {
>>
>> "level" : "error",
>>
>> "schema" : {
>>
>> "loadingURI" : "file:/C:/x3d-code/www.web3d.o
>> rg/specifications/x3d-3.3-JSONSchema.json#",
>>
>> "pointer" : "/definitions/Box"
>>
>> },
>>
>> "instance" : {
>>
>> "pointer" : "/X3D/Scene/-children/5/Transf
>> orm/-children/0/Anchor/-children/0/Shape/-geometry/Box"
>>
>> },
>>
>> "domain" : "validation",
>>
>> "keyword" : "additionalProperties",
>>
>> "message" : "object instance has properties which are not allowed by
>> the schema: [\"@class\"]",
>>
>> "unwanted" : [ "@class" ]
>>
>> }, {
>>
>> "level" : "error",
>>
>> "schema" : {
>>
>> "loadingURI" : "file:/C:/x3d-code/www.web3d.o
>> rg/specifications/x3d-3.3-JSONSchema.json#",
>>
>> "pointer" : "/definitions/IMPORT"
>>
>> },
>>
>> "instance" : {
>>
>> "pointer" : "/X3D/Scene/-children/24/IMPORT"
>>
>> },
>>
>> "domain" : "validation",
>>
>> "keyword" : "type",
>>
>> "message" : "instance type (object) does not match any allowed
>> primitive type (allowed: [\"array\"])",
>>
>> "found" : "object",
>>
>> "expected" : [ "array" ]
>>
>> }, {
>>
>> "level" : "error",
>>
>> "schema" : {
>>
>> "loadingURI" : "file:/C:/x3d-code/www.web3d.o
>> rg/specifications/x3d-3.3-JSONSchema.json#",
>>
>> "pointer" : "/definitions/EXPORT"
>>
>> },
>>
>> "instance" : {
>>
>> "pointer" : "/X3D/Scene/-children/25/EXPORT"
>>
>> },
>>
>> "domain" : "validation",
>>
>> "keyword" : "type",
>>
>> "message" : "instance type (object) does not match any allowed
>> primitive type (allowed: [\"array\"])",
>>
>> "found" : "object",
>>
>> "expected" : [ "array" ]
>>
>> } ]
>>
>> --- END C:\x3d-code\www.web3d.org\x3d\stylesheets\test\HelloWorldPro
>> gramOutput.json---
>>
>> Java Result: 100
>>
>> =====================================
>>
>> p.s. John it looks like MetadataString "@value conversion is incorrectly
>> encoding " as " instead of \" (though #comment and other values look
>> OK), will work on it.
>>
>> all the best, Don
>>
>> --
>>
>> Don Brutzman Naval Postgraduate School, Code USW/Br brutzman at nps.edu
>> <mailto: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
>>
>>
>
> 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/brutzma
> n
>
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