How to listen to the window scroll event in a VueJS component?

In my experience, using an event listener on scroll can create a lot of noise due to piping into that event stream, which can cause performance issues if you are executing a bulky handleScroll function.

I often use the technique shown here in the highest rated answer, but I add debounce on top of it, usually about 100ms yields good performance to UX ratio.

Here is an example using the top-rated answer with Lodash debounce added:

import debounce from 'lodash/debounce';

export default {
  methods: {
    handleScroll(event) {
      // Any code to be executed when the window is scrolled
      this.isUserScrolling = (window.scrollY > 0);
      console.log('calling handleScroll');
    }
  },

  mounted() {
    this.handleDebouncedScroll = debounce(this.handleScroll, 100);
    window.addEventListener('scroll', this.handleDebouncedScroll);
  },

  beforeDestroy() {
    // I switched the example from `destroyed` to `beforeDestroy`
    // to exercise your mind a bit. This lifecycle method works too.
    window.removeEventListener('scroll', this.handleDebouncedScroll);
  }
}

Try changing the value of 100 to 0 and 1000 so you can see the difference in how/when handleScroll is called.

BONUS: You can also accomplish this in an even more concise and reuseable manner with a library like vue-scroll. It is a great use case for you to learn about custom directives in Vue if you haven't seen those yet. Check out https://github.com/wangpin34/vue-scroll.

This is also a great tutorial by Sarah Drasner in the Vue docs: https://v2.vuejs.org/v2/cookbook/creating-custom-scroll-directives.html

For Vue 3 users

In vue3 you should use unmounted or beforeUnmount, instead of beforeDestroy.

Lifecycle hook beforeDestroy is not emitted in Vue3

Here's what works directly with Vue custom components.

 <MyCustomComponent nativeOnScroll={this.handleScroll}>

or

<my-component v-on:scroll.native="handleScroll">

and define a method for handleScroll. Simple!

Actually I found a solution. I add an event listener on the scroll event when the component is created and remove the event listener when the component is destroyed.

export default {
  created () {
    window.addEventListener('scroll', this.handleScroll);
  },
  destroyed () {
    window.removeEventListener('scroll', this.handleScroll);
  },
  methods: {
    handleScroll (event) {
      // Any code to be executed when the window is scrolled
    }
  }
}

Hope this helps!