Controlled components not possible

[aidanhs]

See yewstack/yew#233 (comment) for context.

Essentially, the desired behavior is: if an edit for a field (e.g. an input or text area) is 'rejected' (i.e. not applied to the model), the render should not update. In react this is known as 'controlled components'.

In draco you can test this by applying the patch I've pasted at the bottom and then editing the username input element on the form example. Because the internal state isn't changing, arguably neither should the render. Unfortunately, it does.

React solves this by restoring state after a change event (described on the linked issue). Note that react also provides uncontrolled components where the value field is not set. I think the important thing is that both options are available (somehow).

diff --git a/examples/form.rs b/examples/form.rs
index b70b1d0..bb7c0a7 100644
--- a/examples/form.rs
+++ b/examples/form.rs
@@ -59,7 +59,7 @@ impl draco::App for Form {
                     .attr("id", "username")
                     .attr("name", "username")
                     .attr("value", self.username.clone())
-                    .on_input(Message::UpdateUsername),
+                    /*.on_input(Message::UpdateUsername)*/,
             )
             .push(
                 h::button()