I am using elmish, which I think is similar enough: every component has its own update method and events it dispatches.The events get wrapped in every parent component until it gets to the root, there it gets unwrapped and passed to the appropiate child update method. At any point, you can intercept the event/update.

(Each component consists of a view, a model and an update function, the model contains wrapped versions of the children models and dispatched updates get passed into the children updates)