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Swapping Views

Switching between different markups within a component.

View API​

Controls which element is displayed under a component

For animated swaps, check the View Transitions guide to coordinate custom effects and the browser View Transition API.

function MyView(this: Tama.Component) {
  this.view.set(<div>Hello World!</div>)

  setTimeout(() => {
    this.view.set(<div>I'm Replaced!</div>)
  }, 1_000)
}

In TypeScript, by typing this will cast a Tama Component signature to your function, which will reduce chances of using this functions out of JSX Inflator.

As you already know a component can return nothing - it may set a view via this.view.set. return in a Tama Component Factory function calls this.view.set internally. return also defines a default view for a component under this.view.default property for re-usage.

Caching Elements​

Optionally, you can optimize your elements by inflating them beforehand.

function MyView(this: Tama.Component) {
  const helloWorldView = this.inflator.inflate(<div>Hello World!</div>)
  const replacedView = this.inflator.inflate(<div>I'm Replaced!</div>)

  this.view.set(helloWorldView)
  setTimeout(() => this.view.set(replacedView), 1_000)
  setTimeout(() => this.view.set(helloWorldView), 1_000)
  setTimeout(() => this.view.set(replacedView), 1_000)
}

Or using the same JSX since inflated JSX elements are cached automatically

function MyView(this: Tama.Component) {
  const helloWorldView = <div>Hello World!</div>
  const replacedView = <div>I'm Replaced!</div>

  this.view.set(helloWorldView)
  setTimeout(() => this.view.set(replacedView), 1_000)
  setTimeout(() => this.view.set(helloWorldView), 1_000)
  setTimeout(() => this.view.set(replacedView), 1_000)
}
tip

Or use Tama.Switch helper.

Generators​

Using yield will be calling this.view.set for each one as well allowing you to swap views without explicitly using this

async function* MyView() {
  yield <Loader />

  await new Promise(resolve => setTimeout(resolve, 1_000))

  return <div>I'm loaded!</div>
}

Using synchronous generators doesn't really make sense since only last item always will be delivered, so its behavior is not changed. This code will be rendered as iterable, though return will not have any effect.

function* MyView() {
  yield <Loader />
  yield <div>I'm loaded!</div>
}

Equals to

function MyView() {
  return [<Loader />, <div>I'm loaded!</div>]
}