View & Data API: Working with layers

By Philippe Leefsma

Here is a quickie for the weekend. The following code illustrates how to iterate all the layer groups and their child nodes, then how to isolate a specific layer based on its name similarly to a user clicking on that layer from the Layers panel in UI.

Below is the signature of the function used to isolate a layer:

 1 /**
 2  * Set visibility for a single layer, or for all layers.
 3  *
 4  * Not yet implemented for 3D.
 5  *
 6  * @param {?Array} nodes - An array of layer nodes, 
 7  *        or a single layer node, or null for all layers
 8  *        
 9  * @param {boolean} visible - true to show, false to hide
10  * 
11  * @param {boolean=} [isolate] - true to isolate the layer
12  */
13 Autodesk.Viewing.Viewer3D.prototype.setLayerVisible = 
14 function (nodes, visible, isolate)

I am implementing my code as an extension so it can be very easily reused or tested on your side:

 1 ///////////////////////////////////////////////////////////////////////////////
 2 // Layers viewer extension
 3 // by Philippe Leefsma, January 2015
 4 //
 5 ///////////////////////////////////////////////////////////////////////////////
 6 AutodeskNamespace("Autodesk.ADN.Viewing.Extension");
 7 
 8 Autodesk.ADN.Viewing.Extension.Layers = function (
 9     viewer,
10     options) {
11 
12     Autodesk.Viewing.Extension.call(
13         this,
14         viewer,
15         options);
16 
17     var _self = this;
18 
19     var _viewer = viewer;
20 
21     _self.load = function () {
22 
23         var root = _viewer.model.getLayersRoot();
24 
25         if(root == null) {
26 
27             console.log("No layer information...");
28             return;
29         }
30 
31         console.log(root);
32 
33         for (var i = 0; i < root.childCount; i++) {
34 
35             var group = root.children[i];
36 
37             console.log(group);
38 
39             for (var j = 0; j < group.childCount; j++) {
40 
41                 var layer = group.children[j];
42 
43                 if (layer.name ===
44                     "ORN-A-B-01-BDYGRD-XX-XXXX-MAS|A-Cols") {
45 
46                     _viewer.setLayerVisible(
47                         [layer],
48                         true,
49                         true);
50                 }
51             }
52         }
53 
54         console.log(
55           'Autodesk.ADN.Viewing.Extension.Layers loaded');
56         
57         return true;
58     };
59 
60     _self.unload = function () {
61 
62         console.log(
63           'Autodesk.ADN.Viewing.Extension.Layers unloaded');
64         
65         return true;
66     };
67 };
68 
69 Autodesk.ADN.Viewing.Extension.Layers.prototype =
70     Object.create(Autodesk.Viewing.Extension.prototype);
71 
72 Autodesk.ADN.Viewing.Extension.Layers.prototype.constructor =
73     Autodesk.ADN.Viewing.Extension.Layers;
74 
75 Autodesk.Viewing.theExtensionManager.registerExtension(
76     'Autodesk.ADN.Viewing.Extension.Layers',
77     Autodesk.ADN.Viewing.Extension.Layers);

Layer groups are being dumped into the browser debug window as illustrated in that screenshot:

You can download the code from the following link:
Autodesk.ADN.Viewing.Extension.Layers