Calls method `readRainbow` when a click event is triggered on this button element (or its children) and passes in the event object.
@cheatsheetItem
`<div title="Hello {{ponyName}}">`|`{{ponyName}}`
Binds a property to an interpolated string, e.g. "Hello Seabiscuit". Equivalent to:
`<div [title]="'Hello' + ponyName">`
@cheatsheetItem
`<p>Hello {{ponyName}}</p>`|`{{ponyName}}`
Binds text content to an interpolated string, e.g. "Hello Seabiscuit".
@cheatsheetItem
`<my-cmp [(title)]="name">`|`[(title)]`
Sets up two-way data binding. Equivalent to: `<my-cmp [title]="name" (title-change)="name=$event">`
@cheatsheetItem
`<video#movieplayer...>
<button(click)="movieplayer.play()">
</video>`|`#movieplayer`|`(click)`
Creates a local variable `movieplayer` that provides access to the `video` element instance in data-binding and event-binding expressions in the current template.