util.setByPath(object, path, value, delim)

Set a value at the path in a nested object. delim is the delimiter used in the path. Returns the augmented object.

joint.util.setByPath({ a: 1 }, 'b/bb/bbb', 2, '/');
/*
{
 "a": 1,
 "b": {
  "bb": {
   "bbb": 2
  }
 }
}
*/