refresh the ui from outside dom event handlers?

Not sure this is a good idea, perhaps I am missing a trick. I was trying to render a loading screen until an async operation completes:

```JavaScript
function render(model) {
  if (model.stuff)
    return h('div.stuff', model.stuff);
  else
    return h('div.loading', 'Loading...');
}

var model = { stuff: null };

loadSomeStuff(function(error, stuff) {
   model.stuff = stuff;
   // tell plastiq the model has changed...
});
```

I also tried attaching an onload handler in render, which seems more consistent but didn't work and I'm not sure that's a good idea either. Am I missing an alternative?