Trait Component

Source

pub trait Component: Sized + 'static {
    // Required method
    fn render(&self) -> VNode;

    // Provided methods
    fn key(self, key: Option<impl KeyType>) -> Keyed<Self> { ... }
    fn build(self) -> VNode { ... }
    fn memoized(self) -> Memoized<Self>
       where Self: PartialEq { ... }
}

Expand description

Implement this trait on a struct to create a component with the struct as props.

The props will be completely controlled by Rust, which makes rendering them relatively simple in Rust. However, since the props struct cannot be constructed in JS, these components cannot be exposed to JS. This means only components written in Rust can render a Component by default.

See export_components! for how to expose components for JS consumption.

§Example

struct Counter(i32);

impl Component for Counter {
  fn render(&self) -> VNode {
    h!(div).build(("Counter: ", self.0))
  }
}

Required Methods§

Source

fn render(&self) -> VNode

The render function.

Do not call this method in another render function. Instead, use Component::build() to include your component.

Provided Methods§

Source

fn key(self, key: Option<impl KeyType>) -> Keyed<Self>

Sets the React key.

Source

fn build(self) -> VNode

Returns a VNode to be included in a render function.

Source

fn memoized(self) -> Memoized<Self>
where Self: PartialEq,

Returns a memoized version of your component that skips rendering if props haven’t changed.

If your component renders the same result given the same props, you can memoize your component for a performance boost.

You have to implement PartialEq on your Component for this to work.

§Example

#[derive(PartialEq)]
struct MessageBox {
  message: Rc<str>,
}

impl Component for MessageBox {
  fn render(&self) -> VNode {
    h!(h1[."message-box"]).build(&*self.message)
  }
}

struct App;

impl Component for App {
  fn render(&self) -> VNode {
    h!(div[#"app"]).build(
      MessageBox {
        message: Rc::from("Hello World!"),
      }
      .memoized()
      .build()
    )
  }
}