[x3d-public] loading DOM VRML Script. Cobweb enhancement?

yottzumm at gmail.com yottzumm at gmail.com
Sun Dec 4 14:32:29 PST 2016


I view JSON as simpler to use than DOM.  I like what I did with the prototype expander, adding functionality to X3DOM without having to use DOM (I used X3DJSONLD to create the DOM from the prototype expander JSON).  JSON does has it’s disadvantages…I haven’t figured out how to do a listener/event handler/observer on tree changes yet.

One of the reasons I took on JSON is for  “JSON transformation by demonstration”  I’d like to be able to transform the JSON with a GUI and have the series of steps recorded in a script.  First though, I have to learn JSON transformation.  Using XML for transformation has already been done—see XSLT, and IBM did XSL(T)bydemo, I believe (and there’s JOLT in Java).  I have my own jtbd repository on GitHub, which basicially takes a list of JSON indices down a JSON tree down to a character and copies it to another tree.  There’s also jsondemons, but that’s been morphed into a kind of 3D graph.

John

Sent from Mail for Windows 10

From: Andreas Plesch
Sent: Sunday, December 4, 2016 1:42 PM
To: John Carlson
Cc: X3D Graphics public mailing list; Roy Walmsley; Don Brutzman
Subject: Re: loading DOM VRML Script. Cobweb enhancement?

Hi John,
X3dom is designed to work with the XML encoding or a dom. So for x3dom it would be necessary to first create a DOM from the json. It will be difficult to get around that.
Cobweb has parsers which parse XML or vrml into a scene graph. So it should be possible to make a parser for json, probably following what the XML parser does. But the easier path would be also to create a DOM from the json first.
How do you envision you or others would use json encoded x3d content to add value to a project ? Easier manipulation as a js object ? Easier programmatic content creation ? As an exchange/transmission format, a bit similar to gltf ?

http://www.web3d.org/x3d/content/examples/Basic/ScriptConformance/
has good examples to test scripting. For example,
http://www.web3d.org/x3d/content/examples/Basic/ScriptConformance/TouchSensorIsOverEventECMAScriptIndex.html
http://www.web3d.org/x3d/content/examples/Basic/ScriptConformance/TouchSensorIsOverEventECMAScript.json
I may give this example a try with the json loader and cobweb.
-Andreas

On Dec 4, 2016 1:49 AM, "John Carlson" <yottzumm at gmail.com> wrote:
Perhaps it's time for me to dig into Cobweb and X3DOM to see how they can be extended to support JSON?  If it's through DOM, which is fine by me, I would have to look and see how the various encodings are loaded after DOM is loaded.

On Dec 4, 2016 1:40 AM, "John Carlson" <yottzumm at gmail.com> wrote:
Again, the X3D JSON Loader is a proof of concept patch until we get full JSON support in Cobweb and X3DOM, if desired.

On Dec 4, 2016 1:24 AM, "John Carlson" <yottzumm at gmail.com> wrote:
Because I may not have the full x3d examples downloaded.   And I do want to test to see if JSON inclusion works.

On Dec 2, 2016 3:04 PM, "Andreas Plesch" <andreasplesch at gmail.com> wrote:
Hi John,

I tried a bit to load gears.json with X3DJSONLD:

https://raw.githubusercontent.com/andreasplesch/X3DJSONLD/master/AP_minimal_JSLD.html

But even before any script parsing/loading, there is a problem with the ExternProtoDeclare node in gears.json. It has a url field to Rotor.x3d which is replaced by the json loader with Rotor.json before being handed off to cobweb with importDocument(). Cobweb does not know what to do with the Rotor.json file and gives up.

Why modify the url field value ? If the scene author wants to use a .json encoded scene, she will put it in  the url field just like a .wrl encoded scene.

On another note, I agree that eval() cannot be avoided if script should be supported. cobweb itself also uses eval() (after some setup and massaging) to run the x3d script.

type="application/x-vrmlscript" is necessary because without it the web browser will try to run the script "as is" as soon as it gets appended to the page DOM. When cobweb gets a chance to check for the type attribute, it is already too late. So it cannot use the attribute to prevent it from running. It can only not reject it which is what it does.

-Andreas


On Thu, Dec 1, 2016 at 1:02 AM, <yottzumm at gmail.com> wrote:
It appears that Cobweb is fouled up with DOM loading of scripts, even with the additional name value pair.  See gears.x3d/gears.json and load DOM through importDocument.  And independent test would help.  I am not sure which of my X3DCanvases gets loaded first and I am using absolute indexing, so it could be the XML loaded one that is failing.  Basically, we need a good way to load scripts coming in through JSON I think, and the only real way I know how to do it is eval or cobweb with JSON to XML conversion and VRMLscript.  If Cobweb could use the VRMLscript from JSON or DOM, that might be ideal.
 
This is with cobweb 2.4.
 
John
 
Sent from Mail for Windows 10
 
From: yottzumm at gmail.com
Sent: Thursday, December 1, 2016 12:32 AM
To: Andreas Plesch; Don Brutzman; Roy Walmsley
Subject: FW: loading X3D DOM. Latest Cobweb techniques?
 
Would it be possible to get a name/value of  
 
"@type" : "application/x-vrmlscript"
 
On the Script tag in X3D JSON?  I will do some testing here first to see if it will help.
 
John
 
From: yottzumm at gmail.com
Sent: Thursday, December 1, 2016 12:24 AM
To: Andreas Plesch
Subject: RE: loading X3D DOM. Latest Cobweb techniques?
 
One thing I noticed once I got both DOM and XML views loaded, was that I think the DOM VRML script tag was disabled, but the XML one worked.  Was there some attribute to add to the Script tag to make it work?  Can I add it in both XML and DOM?  Thanks, John  I will start email search.
 
 
 




-- 
Andreas Plesch
39 Barbara Rd.
Waltham, MA 02453

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