Trait yew::html::Component[−][src]

pub trait Component: Sized + 'static {
    type Message: 'static;
    type Properties: Properties;
    fn create(ctx: &Context<Self>) -> Self;

    fn view(&self, ctx: &Context<Self>) -> Html;

    fn update(&mut self, ctx: &Context<Self>, msg: Self::Message) -> bool { ... }

    fn changed(&mut self, ctx: &Context<Self>) -> bool { ... }

    fn rendered(&mut self, ctx: &Context<Self>, first_render: bool) { ... }

    fn destroy(&mut self, ctx: &Context<Self>) { ... }
}
Expand description

Components are the basic building blocks of the UI in a Yew app. Each Component chooses how to display itself using received props and self-managed state. Components can be dynamic and interactive by declaring messages that are triggered and handled asynchronously. This async update mechanism is inspired by Elm and the actor model used in the Actix framework.

Associated Types

Messages are used to make Components dynamic and interactive. Simple Component’s can declare their Message type to be (). Complex Component’s commonly use an enum to declare multiple Message types.

The Component’s properties.

When the parent of a Component is re-rendered, it will either be re-created or receive new properties in the context passed to the changed lifecycle method.

Required methods

Called when component is created.

Components define their visual layout using a JSX-style syntax through the use of the html! procedural macro. The full guide to using the macro can be found in Yew’s documentation.

Note that view() calls do not always follow a render request from update() or changed(). Yew may optimize some calls out to reduce virtual DOM tree generation overhead. The create() call is always followed by a call to view().

Provided methods

Called when a new message is sent to the component via it’s scope.

Components handle messages in their update method and commonly use this method to update their state and (optionally) re-render themselves.

Returned bool indicates whether to render this Component after update.

Called when properties passed to the component change

Returned bool indicates whether to render this Component after changed.

The rendered method is called after each time a Component is rendered but before the browser updates the page.

Note that rendered() calls do not always follow a render request from update() or changed(). Yew may optimize some calls out to reduce virtual DOM tree generation overhead. The create() call is always followed by a call to view() and later rendered().

Called right before a Component is unmounted.

Implementors