Placeholders and size

GoJS
1

Using Placeholders in go.Group, So when a node is dropped into the group does automatically resize itself to surround its member nodes. I want to be able to get the size of the group while automatically resizing it.So how do I get the size of group?

2

The GraphObject.actualBounds will include the size of a Group or its Group.placeholder.

What do you mean by “while automatically resizing it”?

3

So even if I use placeholder, can I get the group size by binding actualBounds？

4

No, probably not. I still don’t understand what your question really is. Since I’m not sure what you are trying to do, I don’t know what to say.

5 
var houseTemplate = 
   g_(go.Group,"Auto",{ ... },
      new go.Binding("background", "isHighlighted", function(h) { return h ? "rgba(255,0,0,0.2)":"transparent"; }).ofObject(),
          g_(go.Shape, "Rectangle",{  fill  : null, stroke  : "#000000",strokeWidth  : 2 },
          //new go.Binding("desiredSize","desiredsize",go.Size.parse).makeTwoWay(go.Size.stringify) ),
          g_(go.Panel, "Vertical", 
            ......
              g_(go.Placeholder,{ 
                      padding  : 5,
                     alignment: go.Spot.Center})));

It is just what I need that using Placeholders in go.Group, So when a node is dropped into the group does automatically resize itself to surround its member nodes.
In the meantime, I want to know the desiredSize of houseTemplate .So I wrote the code :

 new go.Binding("desiredSize","desiredsize",go.Size.parse).makeTwoWay(go.Size.stringify)

With this parameter bound, the size is fixed and the placeholder is invalid.There is conflict between desiredSize and placeholder,how to coordinate it?

6

Either you want to use a Placeholder or not.
https://gojs.net/latest/intro/groups.html
https://gojs.net/latest/intro/sizedGroups.html

It seems to me that your requirements conflict with each other.