Customizable react native component for number animations.

• Examples
• Basic
• Formatting
• Timing function
• Counting
• Props

$ npm install react-native-animate-number

import AnimateNumber from 'react-native-animate-number'

The only required property is value, when this property changes, it automatically interpolates value and performs animation.

<AnimateNumber value={100}/>

You can customize text format by specifying formatter prop, this property must be a function.

<AnimateNumber value={100} formatter={(val) => {
    return '$ ' + parseFloat(val).toFixed(2)
  }}/>

There're 3 built-in timing functions which are linear, easeIn, and easeOut. It is also possible customize your timing function, see examples bellow.

<AnimateNumber value={100} timing="linear"/>
<AnimateNumber value={100} timing="easeOut"/>
<AnimateNumber value={100} timing="easeIn"/>

Customized timing function returns a number which represents the length of animation frame.

interval

Basic interval length of animation frame, default value is 14 ms. You can change this value by interval prop.

progress

A float number between 0 to 1, which means the progress of animation.

<AnimateNumber value={200}
  countBy={1}
  timing={(interval, progress) => {
    // slow start, slow end
    return interval * (1 - Math.sin(Math.PI*progress) )*10
  }}/>

the above example will make an animation like this

By default this component calculates value increment of each animation frame, but you can customize this rule by set prop countBy.

<AnimateNumber value={100} countBy={1} />

But keep in mind if the countBy value is relative small than value, the animation may persists for a very long time. Like the following example, it will tasks 150 seconds to finish the animation.

<AnimateNumber value={10000} interval={15} countBy={1} />

The value of AnimateNumber component.

Set this property to force the component's value increase/decrease by this number.

Base interval of each animation frame, in ms.

Set total frame number of animation, say, if interval is 14 and steps is 30, the animation will take 14x30ms to finish when it uses linear timing function.

Custom timing function or use a default timing function.

This prop accepts a function which returns a string as displayed value.

A function that triggers when text state has updated.

A function that triggers when animation completes.