Event handling from a child component to parent

This sample introduce the concept of hydro event communication from child component to parent.

One point of caution, in MessageButton.cshtml, it's not enough to have the button tag as a root component because it will disappear once you click the button. You need to have a div or other container tag to keep the button rerendered.

<div>
    <button on:click="@(() => Model.Show("This greeting comes from MessageButton component"))">Show</button>
</div>