Funny enough on this page
https://www.blend4web.com/en/community/article/63/
the app works on my machine…. In Firefox.

For support of webgl in fedora you have to go back in 2012 to find anything. The more recent post all being about firefox changing some GL parameter under the hood to avoid more crashes. I don't think that's it. And i'm running X11 not wayland.
And again it all works perfectly fine as long as they are no for loops in custom.js

no message in the console. Just the preloader that freezes. I'm on Fedora26_64 bit using firefox 55.
I don't have chrome on this machine.
EDIT : Chromium fails to open cartoon interior to.

I noticed there is a for loop in toon furniture so i tried to launch it from the project manager on my local copy of B4W… well it doesn't launch…

Hy i had a really bad time trying to get my scene onloader loop over previously loade scenes and i had to use a while loop. My conclusion B4W doesn't support for loops.
So i started a new porject added a simple for loop and it failed to load.

in the broswers console if i type it directly it work :

    for (i=0; i<9; i++) {
    console.log(i)
    }
0 
1 
2 
3 
4 
5 
6 
7 
8

but if you add it to app.js it fails and B4W never loads.

I attach a simple app to illustrate the problem.

If it come from my setup let mee know. I'm using B4W 17-06 with B3D 2.8c

I am starting to wonder if B4W supports for loops
so it works as follow

    function unloadPrev(){

    console.log('unload');
    console.log(data_id_counter);
    var i = 1
    while ( i <= data_id_counter ){
        console.log(i)
        m_data.unload(i);
        i++
    }

I cant seem to make my unloader work…
Could someone take a look. They must be somethng pretty obvious.

function unloadPrev(){
	data_id_counter += 1
	console.log('unload');
	console.log(data_id_counter);
	console.log( m_scenes.get_all_objects("MESH",data_id_counter).length);
	console.log( m_scenes.get_all_objects("MESH",data_id_counter))
	console.log('#############');
	if (data_id_counter > 1){
		for (i=1; i < data_id_counter; i ++){
			 console.log( m_scenes.get_all_objects("MESH",i));
			if ( m_scenes.get_all_objects("MESH",i).length > 0 ) {
				
				m_data.unload(i);
			}
		}
		return

	}
	else {
		return
	}

}

Here a my logs in the browser. You'll notice a long a the for loop doesn't start i get the callback. That's what loads the scene. But as soon a it starts looping it fails and the callback functins are not called…

unload  character:241:10
1  character:242:10
0  character:243:10
Array [  ]  character:244:10
#############  character:245:10
callback  character:266:10
callbackDone  character:273:10
callback  character:266:10
callbackDone  character:273:10
unload  character:241:10
2  character:242:10
1  character:243:10
Array [ Object ]  character:244:10
#############  character:245:10
unload  character:241:10
3  character:242:10
0  character:243:10
Array [  ]  character:244:10
#############  character:245:10
unload  character:241:10
4  character:242:10
0  character:243:10
Array [  ]  character:244:10
#############

EDIT : i have moved the incrementer for data_id_counter to get the right number. It wasn't called often enough here.

Hy I just noticed that on the mobile version of the site on chrome the menu is always open on page load. I think it should be closed.
Just to let you know.

Luke

OK so i'm solving this nice and gently.
In fact i'm pushing all the logic after the object is loaded in the loaded_cb. The question now is how do i keep trace of the object location variable????
Got to find a way…

There you go !
some python magic (positionObject is a empty object )

positionObject.{{artefact}} = m_scenes.get_object_by_name("{{artefact.position}}");

to build a object with all my position objects names after the element that going to that position
AND :

function loaded_cb(data_id) {
    var scene_object_list = m_scenes.get_all_objects("MESH",data_id);
    var positionName = scene_object_list[0].name
    m_const.append_copy_trans(scene_object_list[0], positionObject[positionName])

templating JS loops with python and keeping track of the scope isn't the easiest trick i've seen today

Ok so it works only never the first time. I need to click twice my loader link to get someting in

var scene_object_list = m_scenes.get_all_objects("MESH",1);

Is there a way of forcing a update of that list. Or should i set it in a callback??

document.getElementById("rightHandedSwordMan").addEventListener("click", function(e) {
    e.preventDefault();
    console.log('sword_ACbtDLE');
    m_data.load( "../media/artefacts/sword_ACbtDLE.json");
										  
    var positionObjectsword_ACbtDLE = m_scenes.get_object_by_name("handRightPos");
    var scene_object_list = m_scenes.get_all_objects("MESH",1);
    console.log(scene_object_list);

Thanks! I will give that a try.