I'm looking to start using a standard pattern in our UIs to split our model and views, similar to the points discussed in jupyter-widgets/ipywidgets#2296. However when extending to more complex or nested views it's rather inconvenient to have to define all the links separately as we need to hold a reference to every field.

Instead I'd been keen to introduce the ability to set links directly on traits. This way I can bind to the view's traits without needing to hold a reference to the object. Proposing something along the following lines so that it's backwards compatible with current traitlet usage.

from traitlets import SourceLink, Float, HasTraits
import ipywidgets as widgets

class Model(HasTraits):
   a = Float()

def view(model):
    return widgets.HBox([
        widgets.Label("Value A"),
        widgets.FloatText(value = SourceLink(model, "a"))
    ])

x1 = Model()
view(x1)

Having tested locally I think this is easily achievable with minimal changes. However before submitting a PR I wanted to check if any views or comments on the idea or how to approach it.