useMotionValueEvent

useMotionValueEvent manages a motion value event handler throughout the lifecycle of a Vue component.

<script setup>
  import { useMotionValue, useMotionValueEvent } from "motion-v"
  const x = useMotionValue(0)
  
  useMotionValueEvent(x, "animationStart", () => {
    console.log("animation started on x")
  })
  
  useMotionValueEvent(x, "change", (latest) => {
    console.log("x changed to", latest)
  })
</script>

<template>
   <motion.div :style="{ x }" />
</template>

When the component is unmounted, event handlers will be safely cleaned up.

Usage

Import from Motion:

import { useMotionValueEvent } from "motion-v"

To add an event listener to a motion value, provide the value, event name and callback:

const color = useMotionValue("#00f")

useMotionValueEvent(color, "change", (latest) => {
  console.log(latest)
})

Available events are:

• change

• animationStart

• animationComplete

• animationCancel

"change" events are provided the latest value of the motion value.

Advanced

useMotionValueEvent is a helper function for a motion value's on method. With on, you can start listening to events whenever you like, for instance within an event handler. But remember to also unsubscribe when the component unmounts.

watch([x, y],(n,o,onCleanUp) => {
  const doSomething = () => {}
  
  const unsubX = x.on("change", doSomething)
  const unsubY = y.on("change", doSomething)
  
  onCleanUp(() => {
    unsubX()
    unsubY()
  })
},{
  immediate:true
})