vue virtual scroll list

Table of contents

• Advantages
• Live demo
• Simple usage
• Props type
  • Required props
  • Optional props
  • Public methods
• Attentions

Advantages

• Only 3 required props, simple and very easy to use.

• Big data list with high render performance and efficient.

• You don’t have to care about item size, it will calculate automatic.

Live demo

https://tangbc.github.io/vue-virtual-scroll-list

https://codesandbox.io/s/live-demo-virtual-list-e1ww1

Simple usage

npm install vue-virtual-scroll-list --save

Root component:

<template>
  <div>
    <virtual-list style="height: 360px; overflow-y: auto;" // make list scrollable
      :data-key="'uid'"
      :data-sources="items"
      :data-component="itemComponent"
    />
  </div>
</template>

<script>
  import Item from './Item'
  import VirtualList from 'vue-virtual-scroll-list'

  export default {
    name: 'root',
    data () {
      return {
        itemComponent: Item,
        items: [{uid: 'unique_1', text: 'abc'}, {uid: 'unique_2', text: 'xyz'}, ...]
      }
    },
    components: { 'virtual-list': VirtualList }
  }
</script>

Item component:

<template>
  <div>{{ index }} - {{ source.text }}</div>
</template>

<script>
  export default {
    name: 'item-component',
    props: {
      index: { // index of current item
        type: Number
      },
      source: { // here is: {uid: 'unique_1', text: 'abc'}
        type: Object,
        default () {
          return {}
        }
      }
    }
  }
</script>

More usages or getting start you can refer to these clearly examples.

Props type

Required props

Prop	Type	Description
data-key	String|Function	The unique key get from data-sources in each data object. Or a function called with each data-source and return their unique key. Its value must be unique in data-sources, it is used for identifying item size.
data-sources	Array[Object]	The source array built for list, each array data must be an object and has an unique key get or generate for data-key property.
data-component	Component	The render item component created / declared by vue, and it will use the data object in data-sources as render prop and named: source.

Optional props

Commonly used

Prop	Type	Default	Description
keeps	Number	30	How many items you are expecting the virtual list to keep rendering in the real dom.
extra-props	Object	{}	Extra props assign to item component that are not in data-sources. Notice: index and source are both occupied inner.
estimate-size	Number	50	The estimate size of each item, if it is closer to the average size, the scrollbar length looks more accurately. It is recommended to assign the average that calculate by yourself.

Uncommonly used

Prop	Type	Default	Description
start	Number	0	Setting scroll position stay start index.
offset	Number	0	Setting scroll position stay offset.
scroll	Event		Emited when scrolling, param (event, range).
totop	Event		Emited when scrolled to top or left, no param.
tobottom	Event		Emited when scrolled to bottom or right, no param.
resized	Event		Emited when item resized (mounted), param (id, size).
direction	String	vertical	Scroll direction, available values are vertical and horizontal
page-mode	Boolean	false	Let virtual list using global document to scroll through the list.
top-threshold	Number	0	The threshold to emit totop event, attention to multiple calls.
bottom-threshold	Number	0	The threshold to emit tobottom event, attention to multiple calls.
root-tag	String	div	Root element tag name.
wrap-tag	String	div	List wrapper element (role=group) tag name.
wrap-class	String		List wrapper element class name.
wrap-style	Object	{}	List wrapper element inline style.
item-tag	String	div	Item wrapper element (role=item) tag name.
item-class	String		Item wrapper element class name.
item-class-add	Function		A function that you can return extra class (String) to item wrapper element, param (index).
item-style	Object	{}	Item wrapper element inline style.
item-scoped-slots	Object	{}	The $scopedSlots for item component.
header-tag	String	div	For using header slot, header slot wrapper element (role=header) tag name.
header-class	String		For using header slot, header slot wrapper element class name.
header-style	Object	{}	For using header slot, header slot wrapper element inline style.
footer-tag	String	div	For using footer slot, footer slot wrapper element (role=footer) tag name.
footer-class	String		For using footer slot, footer slot wrapper element class name.
footer-style	Object	{}	For using using footer slot, footer slot wrapper element inline style.

Public methods

Usefull public methods

You can call these methods via ref:

Method	Description
reset()	Reset all state back to initial.
scrollToBottom()	Manual set scroll position to bottom.
scrollToIndex(index)	Manual set scroll position to a designated index.
scrollToOffset(offset)	Manual set scroll position to a designated offset.
getSize(id)	Get the designated item size by id (from data-key value).
getSizes()	Get the total number of stored (rendered) items.
getOffset()	Get current scroll offset.
getClientSize()	Get wrapper element client viewport size (width or height).
getScrollSize()	Get all scroll size (scrollHeight or scrollWidth).
updatePageModeFront()	When using page mode and virtual list root element offsetTop or offsetLeft change, you need call this method manually.

Attentions

This component use an in-place patch strategy to render list instead of v-for and :key. This way achieves the best efficient, but only suitable when your list output does not rely on item component inner state or temporary DOM state (e.g. form input values).

But how to deal with such a situation? Without maintaining inner state, recommend to use props and dispatch (stateless component), here is an example keep-state.

Contributions

Welcome to improve this component with any issue, pull request or code review.

Changelogs

Maintain and update occasionally, for changes see release.

License

MIT License.