gojs apply parameter only when part of group

Question

Using gojs, I would like to apply parameters only when the object is placed inside another object.

for example a panel should only have the padding added (or change value, from 0 to 25) when placed inside a H Group.

is this possible? looking at gojs docs I see SelectionGrouped but not sure if this includes dropping the object into a H Group

myDiagram.nodeTemplateMap.add("j2",
                $(go.Node, "Auto",
                    $(go.Panel, "auto", {padding:0},
                        $(go.Shape, "File"),
                        $(go.TextBlock,  "This\n is a\n file", textStyle(),
                            new go.Binding("text", "text").makeTwoWay())
                    )
                ));

Answer 1

You can fire events when Parts are added to or removed from groups using Group.memberAdded and memberRemoved` https://gojs.net/latest/api/symbols/Group.html#memberAdded

Or you can make a data binding on the Part (that isn't the Group) to do something different when its containingGroup is not null. Example binding:

      new go.Binding("margin", "containingGroup", function(a) {
        if (a === null) return 5;
        // otherwise its in a group:
        return 15;
      }).ofObject(),

See it live here: https://codepen.io/simonsarris/pen/LYNOpme?editors=1010