VueLazily

The easiest way to lazy load your content.

Inspired by vue-promised, recommend to look at it if you need loading/errors handling without lazy loading.

Demo

Features

• ⚔️ Works for both Vue 3 and 2
• 👁️ Loads content when it becomes visible
• 📝 Manipulate data directly in the template
• 📍 Slots for loading and error states
• No dependencies.

Starting from v2 The minimum supported Vue version - 2.7. If you use older version of Vue, please install previous version of this library - ^1.0.0.

Why does this library exist?

Usually, on big pages, rendering all content at once can cause performance problems with big "Time to Interactive" or "Largest Contentful Paint" time, or even bigger problem if SSR used - server should render all the content before user could see the page.

And in most cases, the user will not even scroll to that content, but must wait to it to be rendered.

VueLazily solves these problems by loading data only when it becomes visible and handle loading/error state itself using slots 🙂.

Installation

yarn add vue-lazily

or

npm i vue-lazily

Usage

Global

// Vue 2

import Vue from 'vue'
import VueLazily from 'vue-lazily'

Vue.use(VueLazily, { /* options */ })


// Vue 3

import { createApp } from 'vue'
import VueLazily from 'vue-lazily'

const app = createApp(App)
app.use(VueLazily, { /* options */ }))

Local

<script>
import { Lazily } from 'vue-lazily'

export default {
  components: {
    Lazily
  }
}
</script>

Basic Example

Using url string:

<template>
  <Lazily
    action="https://rickandmortyapi.com/api/character/1"
    #default="{ data: { image, name, species } }"
  >
    <img :src="image" :alt="name" />
    <h2>{{ name }}</h2>
    <span>{{ species }}</span>
  </Lazily>
</template>

Using component's method:

<template>
  <Lazily :action="getCharacter" #default="{ data: { image, name, species } }">
    <img :src="image" :alt="name" />
    <h2>{{ name }}</h2>
    <span>{{ species }}</span>
  </Lazily>
</template>

<script>
export default {
  methods: {
    getCharacter() {
      return fetch('https://rickandmortyapi.com/api/character/1').then(res =>
        res.json()
      )
    }
  }
}
</script>

Using slots:

<template>
  <Lazily action="https://rickandmortyapi.com/api/character/1">
    <template #pending>Loading...</template>
    <template #error="{ error }">{{ error.message }}</template>
    <template #default="{ data: { image, name, species } }">
      <img :src="image" :alt="name" />
      <h2>{{ name }}</h2>
      <span>{{ species }}</span>
    </template>
  </Lazily>
</template>

API Reference

options

Name	Description	Type
name	Component name. Defaults to Lazily	String
props	Props which will be passed to component	Object

props

All of these props could be passed to global config as well as directly to component.

Name	Description	Type
action	Url string, method or promise for default action handler. Or anything else that could be passed to custom actionHandler	any
lazy	Enables lazy loading which uses Intersection Observer API under the hood. Defaults to true	Boolean
delay	Delay in ms to wait before displaying the pending slot. Disabled by default, if passed true - defaults to 200. If disabled - pending slot will be rendered in SSR	Boolean Number
margin	rootMargin option for IntersectionObserver class. Defaults to 0px. See docs	String
threshold	threshold option for IntersectionObserver class. Defaults to 0. See docs	String
height	Height of an element that is shown before pending slot. Defaults to 0px	String
watch	Reactive value or watch function to watch changes and rerun action	Number String Array Object Function
actionHandler	Custom action handler. F.e. to use custom fetch, axios or apollo. Gets action prop as argument	Function

slots

All slots can be used as scoped or regular slots.

Name	Description	Scope
pending	Content to display while the action is pending and before delay is over	previously resolved data, observed flag
default	Content to display once the action has been successfully resolved	resolved data
error	Content to display if the action is rejected	throwed error
combined	Combines all slots to provide a granular control over what should be displayed	context object

🤝 Contributing

Contributions, issues and feature requests are welcome!
Feel free to check issues page.

Show your support

Give a ⭐️ if this project helped you!

License

MIT