Spring
Overview
import { Spring, animated } from 'react-spring'
Turns values into animated-values.
Either: overwrite values to change the animation
If you re-render the component with changed props, the animation will update.
<Spring opacity={toggle ? 1 : 0}>
{styles => ...}
</Spring>
Or: pass a SpringRef and update using the api
It will not cause the component to render like an overwrite would (the animation still executes of course). Handling updates like this is useful for fast-occurring updates, and you should generally prefer it as it's more powerful. Further documentation can be found in Imperatives & Refs
const springRef = new SpringRef()
springRef.start({
to: {
opacity: 1
}
})
<Spring ref={springRef} from={{ opacity: 0 }}>
{styles => ...}
</SpringRef>
Finally: distribute animated props among the view
The child of Spring is a render prop function.
;(styles) => <animated.div style={styles}>i will fade</animated.div>
Properties
All properties documented in the common props apply.
Additional notes
To-prop shortcut
Any property that Spring does not recognize will be combined into "to", for instance opacity: 1 will become to: { opacity: 1 }.
// This ...
<Spring opacity={1} color={'red'} />
// is a shortcut for this ...
<Spring to={{ opacity: 1, color: 'red' }} />
Async chains/scripts
The to prop also allows you to 1. script your animation, or 2. chain multiple animations together. Since these animations will execute asynchronously, make sure to provide a from property for base values (otherwise, props will be empty).
This is how you create a script
class AsyncExample extends PureComponent {
handleAsyncTo = async (next, cancel) => {
await next({ opacity: 1, color: '#ffaaee' })
await next({ opacity: 0, color: 'rgb(14,26,19)' })
}
render() {
// ...
return (
<Spring to={handleAsyncTo} from={{ opacity: 0, color: 'red' }}>
{(styles) => <animated.div style={styles}>I will fade in and out</animated.div>}
</Spring>
)
}
}