Form elements, how to pre-fill fields?

Let's say i have a ui-text-input and want to pre-fill it with the content of msg.exampleText when the page loads.

How do I do that?

At the moment you can't.

There is an open issue for this.

Edit: The title says Form, but you also reference ui-text-input. Which is it? for ui-text-input you can pass the text in msg.payload