[x3d-public] Topics for Discussion at JSON meeting: SFNode/MFNode field/fieldValue content, ProtoBody, regexes

[Don Brutzman]

Same pattern throughout for field, fieldValue:

- simple-type content goes in @value attribute for XML, "-value" key for JSON

- contained node/statement/comment content is embedded in element for XML, goes in "-children" field for JSON


On 2/6/2016 4:05 PM, Roy Walmsley wrote:
> Don,
>
> I don't have any problem with that. What about for default values within a field in a ProtoInterface? Or a Shader? Or a Script?
>
> Roy
>
> -----Original Message-----
> From: Don Brutzman [mailto:brutzman at nps.edu]
> Sent: 06 February 2016 23:11
> To: Roy Walmsley; John Carlson
> Cc: x3d-public at web3d.org
> Subject: Re: [x3d-public] Topics for Discussion at JSON meeting: SFNode/MFNode field/fieldValue content, ProtoBody, regexes
>
> Testing reconsideration:  using "-value" for children SFNode/MFNode content inside a fieldValue can be improved.
>
> Better: use "-children" instead.  Common semantics, simpler encoding rules, easier to remember, less failure prone.
>
> Next version (test suite in progress) will use "-children" instead of "-value" for contained content.
>
> Test suite conversion checks appear to be performing well, update should be complete late tonite.
>
> Examples attached.  As always, comments are welcome.
>
> p.s. here's one comment:  i had great trouble getting "-value" to work properly.  "-children" fell right into place and seems like an obvious improvement, since the earlier "-value" was an arbitrary choice.
>
>
> On 2/5/2016 7:04 PM, Don Brutzman wrote:
>> Summary: Once again the X3D JSON design is looking pretty solid, and our tool suites are pretty powerful at detecting edge-case issues.
>>
>> On 2/5/2016 10:37 AM, Don Brutzman wrote:
>>> [correction: shifted to x3d-public]
>>> [...]
>>> On 2/4/2016 10:56 AM, Roy Walmsley wrote:
>>>> Topics for Discussion for JSON encoding meeting February 5^th 2016 at 1000 PST, 1800 GMT.
>>>> [...]
>>>> 2) *Encoding of node fields in ‘field’ and ‘fieldValue’ elements
>>>> within Script and Prototypes.* [...snip/shuffle...] Illustration of
>>>> 2) above is in X3D Example Archives: Basic, CAD, Cad Geometry Extern
>>>> Prototypes (see
>>>> http://www.web3d.org/x3d/content/examples/Basic/CAD/_pages/page02.ht
>>>> ml)
>>>>
>>>> Find the ProtoInstance named ‘IndexedQuadSet’. It has two fieldValue children. The second has the name ‘coord’, and a child Coordinate node. When converted into JSON this Coordinate node is allocated to a field /-coord/, which is the default containerField name for this node. This is incorrect. It should be allocated to the /-value/ field. This is because the element fieldValue has attributes of ‘name’ and ‘value’.
>>>>
>>>> A similar issue arises with default values for node fields within the field element.
>>
>> OK this change is worth close scrutiny to avoid confusion later.
>>
>> For <field> and <fieldValue>, when the "@value" attribute is used for simple types, everything works OK.
>>
>> For <field> and <fieldValue>, with contained SFNode/MFNode content or contained comments or contained ROUTEs, the key is now "-value" (hyphen instead of ampersand).
>> [...]
>
> Summary, revising the prior sentence:
>
> For <field> and <fieldValue>, with contained SFNode/MFNode content or contained comments or contained ROUTEs, the key is now "-children" as with most other child content.
>
> all the best, Don
>


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