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

[Don Brutzman]

Followup for email thread:  we chose -children (for greater simplicity/consistency) rather than -value

On 2/8/2016 3:03 PM, John Carlson wrote:
> I would prefer if simple type was @value, but I can change it to -value for JSON if desired.
>
> John
>> On Feb 7, 2016, at 12:50 AM, Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>> wrote:
>>
>> 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 <mailto: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 <mailto:brutzman at nps.edu>
>> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
>> X3D graphics, virtual worlds, navy roboticshttp://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/brutzman