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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Hi all,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Interesting questions raised below. I will try to provide some answers.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Q1 – Usually (always) just one field for a given parent nodetype. I don’t have an exhaustive answer, but I will give an example. It may be the only one, not sure. Look at the Collision node, (19775-1, 23.4.2, <a href="http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/navigation.html#Collision">http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/navigation.html#Collision</a>. Note that there is a children field and a proxy field, both of which accept X3DChildNode. In other words, what can go in one can also go in the other. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>The Collision node has a containerField attribute with a default value of “children”. This simply tells us that, unless otherwise specified, it will go into the children field of its parent node.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Similarly, if we look at, for example, MetadataBoolean, it has a containerField with the default value of “metadata”. So, MetadataBoolean, unless otherwise specified, will go into the metadata field of the parent node.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Q2 – ExternProto: Hm… good question. My first thought was that there’s nothing there. But, on reflection, it’s not about the definition using ExternProtoDeclare, or ProtoDeclare. It’s about where you use it. And that means ProtoInstance. Look there, and you see that there is an attribute for containerField, with a default value of “children”. So, if you want the ProtoInstance in some other field, you need to specify a different value for containerField.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Q3 – containerField: I think of the parent node as the “container”, and the “field” is the field that does the containing. And you are right, it is not a field. It is an XML attribute. It is not required, for example, in the classic VRML encoding, or the JSON encoding, because the encoding is such that, for each node, fields have their names explicitly written, followed by their values. So, for Collision, we would write:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Collision {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> children [<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> DEF group1 Group{},<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> DEF group2 Group{}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> ],<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> proxy [<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> DEF group3 Group {}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> ]<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>But, when it comes to XML, if we write<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><Collision><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group1”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group2”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group3”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'></Collision><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Then all three Group nodes would be loaded into the children field of the Collision node, because the default value of the containerField attribute for Group is “children”. So, to reproduce the VRML encoding we write:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><Collision><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group1”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group2”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'> <Group DEF=”group3” containerField=”proxy”/><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'></Collision><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>The only way to definitively know which is the default containerField for any node type is to read it from the schema or DTD.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Hope these comments help,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'>Roy<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> x3d-public [mailto:x3d-public-bounces@web3d.org] <b>On Behalf Of </b>Andreas Plesch<br><b>Sent:</b> 10 October 2016 14:28<br><b>To:</b> X3D Graphics public mailing list <x3d-public@web3d.org><br><b>Subject:</b> Re: [x3d-public] getContainerField() [was cobweb DOM integration]<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><div><div><p class=MsoNormal>Hi Doug,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>good questions.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>Date: Mon, 10 Oct 2016 12:53:22 +0000<br>From: doug sanden <<a href="mailto:highaspirations@hotmail.com">highaspirations@hotmail.com</a>><br>To: X3D Graphics public mailing list <<a href="mailto:x3d-public@web3d.org">x3d-public@web3d.org</a>><br>Subject: Re: [x3d-public] cobweb DOM integration<br><br>if added to SAI SFNode interface, then it might need a parameter: sfnode.getContainerField(parent) since some nodetypes have multiple containerfield targets by fieldname, but usually (Q1. always?) just one field for a given parent nodetype.<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I had the same suspicion and you confirmed that there are nodetypes which have multiple containerfield targets. It may be useful to put together a list of these starting with some examples. Do any come to mind ? I believe cobweb does not accept a parent parameter to the .getContainerField() method, but I may be wrong.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I seem to remember that there are cases where it is necessary to provide an explicit containerField attribute. Not sure what these are, but the fact that there is a containerField attribute indicates that it is sometimes required.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>Q2. in an ExternProto scenario, before extern proto is loaded, and no concrete node as first node of protobody, how to determine via a function what is the containerfield its instances should target their parents? Can we put a field 'containerField' or MFString containerFields? Does cobeweb delay instancing extern protos until the extern is loaded and concretized before allowing getContainerField?<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I did not explore ExternProtos in cobweb sofar, so I do not have answers, But I also suspect that a containerField field can be used. Not sure when instancing occurs but I would also expect after completion of the async, loading of the externproto.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>Q3. terminology: does 'container' part of containerfield refer to the parent ie parent is container or does it refer to the field ie a field is a container?<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I thought 'container' refers to the parent node and 'field' refers to field of the parent. So one would say the 'containerfield field'. But I am not sure if containerfield is a field or just a xml attribute which acts as a helper.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>-Andreas<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>________________________________________<br>From: x3d-public <<a href="mailto:x3d-public-bounces@web3d.org">x3d-public-bounces@web3d.org</a>> on behalf of Andreas Plesch <<a href="mailto:andreasplesch@gmail.com">andreasplesch@gmail.com</a>><br>Sent: October 9, 2016 9:00 PM<br>To: X3D Graphics public mailing list<br>Subject: Re: [x3d-public] cobweb DOM integration<br><br>On Sun, Oct 9, 2016 at 10:35 PM, Andreas Plesch <<a href="mailto:andreasplesch@gmail.com">andreasplesch@gmail.com</a><mailto:<a href="mailto:andreasplesch@gmail.com">andreasplesch@gmail.com</a>>> wrote:<br>...<br>What are other strategies for determining the field in a container node which should (most likely) be set given just the identity of a new node and its containing (parent) node ?<br><br><br>Some more investigating brought to light that cobweb.js already has a node.getContainerField() method which seems to be exactly what I was looking for. Excellent.<br><br>The SAI does not have such a function:<br><br><a href="http://www.web3d.org/documents/specifications/19777-1/V3.3/Part1/functions.html#t-SFNodeFunctions" target="_blank">http://www.web3d.org/documents/specifications/19777-1/V3.3/Part1/functions.html#t-SFNodeFunctions</a><br><br>Should it be added to the spec. ?<br><br>--<br>Andreas Plesch<br>39 Barbara Rd.<br>Waltham, MA 02453<br><br><br><br>--<br>Andreas Plesch<br>39 Barbara Rd.<br>Waltham, MA 02453<br><br><br><br>------------------------------<br><br>Subject: Digest Footer<br><br>_______________________________________________<br>x3d-public mailing list<br><a href="mailto:x3d-public@web3d.org">x3d-public@web3d.org</a><br><a href="http://web3d.org/mailman/listinfo/x3d-public_web3d.org" target="_blank">http://web3d.org/mailman/listinfo/x3d-public_web3d.org</a><br><br><br>------------------------------<br><br>End of x3d-public Digest, Vol 91, Issue 16<br>******************************************<o:p></o:p></p></blockquote></div><p class=MsoNormal><br><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <o:p></o:p></p><div><p class=MsoNormal>Andreas Plesch<br>39 Barbara Rd.<br>Waltham, MA 02453<o:p></o:p></p></div></div></div></div></body></html>