This trait implements some features. The common point in these features is that its are used to update a component.
In most cases, update will be used. on_assemble will be used when a component is mounted first time. on_load will be used when a compoent is mounted from the second time.
You can update your component in on_load by props.
Cmd<Self> is a command to kagura. This usages are descripts later.
Render<Html>
When you create a component to render Html, it is needed to implements Render<Html>.
HtmlComponent
All of implements in this trait are already implemented. This trait is needed to convert a component to a Html node.