React Lazy Fastdom is a fork of React Lazy Load, an easy to use React component which helps you defer loading content in predictable way.
This fork uses fastdom to get the values of the css properties and avoid possible layout/reflow trashing.
Also, visibility of lazy load components is calculated using window
as reference by default. You can also use component inside scrolling container, such as div with scrollbar, but if you want to do that, the container element must be explicitly defined through the container
prop.
React Lazy Load requires React 0.14 or later.
npm install --save react-lazy-fastdom
import React from 'react';
import LazyLoad from 'react-lazy-fastdom';
const MyComponent = () => (
<div>
Scroll to load images.
<div className="filler" />
<LazyLoad height={762} offsetVertical={300}>
<img src='http://apod.nasa.gov/apod/image/1502/HDR_MVMQ20Feb2015ouellet1024.jpg' />
</LazyLoad>
<div className="filler" />
<LazyLoad height={683} offsetTop={200}>
<img src='http://apod.nasa.gov/apod/image/1502/2015_02_20_conj_bourque1024.jpg' />
</LazyLoad>
<div className="filler" />
<LazyLoad height={480} offsetHorizontal={50}>
<img src='http://apod.nasa.gov/apod/image/1502/MarsPlume_jaeschke_480.gif' />
</LazyLoad>
<div className="filler" />
<LazyLoad
height={720}
onContentVisible={() => console.log('look ma I have been lazyloaded!')}
>
<img src='http://apod.nasa.gov/apod/image/1502/ToadSky_Lane_1080_annotated.jpg' />
</LazyLoad>
<div className="filler" />
</div>
);
Type: Number|String
Default: 0
Aliases: threshold
The offset
option allows you to specify how far below, above, to the left, and to the right of the viewport you want to begin displaying your content. If you specify 0
, your content will be displayed as soon as it is visible in the viewport, if you want to load 1000px below or above the viewport, use 1000
.
Type: Number|String
Default: offset
's value
The offsetVertical
option allows you to specify how far above and below the viewport you want to begin displaying your content.
Type: Number|String
Default: offset
's value
The offsetHorizontal
option allows you to specify how far to the left and right of the viewport you want to begin displaying your content.
Type: Number|String
Default: offsetVertical
's value
The offsetTop
option allows you to specify how far above the viewport you want to begin displaying your content.
Type: Number|String
Default: offsetVertical
's value
The offsetBottom
option allows you to specify how far below the viewport you want to begin displaying your content.
Type: Number|String
Default: offsetVertical
's value
The offsetLeft
option allows you to specify how far to left of the viewport you want to begin displaying your content.
Type: Number|String
Default: offsetVertical
's value
The offsetRight
option allows you to specify how far to the right of the viewport you want to begin displaying your content.
Type: Number|String
Default: 250
The throttle is managed by an internal function that prevents performance issues from continuous firing of scroll
events. Using a throttle will set a small timeout when the user scrolls and will keep throttling until the user stops. The default is 250
milliseconds.
Type: Boolean
Default: true
By default the throttling function is actually a debounce function so that the checking function is only triggered after a user stops scrolling. To use traditional throttling where it will only check the loadable content every throttle
milliseconds, set debounce
to false
.
Type: String|Number
The height
option allows you to set the element's height even when it has no content.
Type: String|Number
The width
option allows you to set the element's width even when it has no content.
Type Function
A callback function to execute when the content appears on the screen.
Type Element|Window
A reference to a DOM element used for calculating visibility of LazyLoad components.
The default is window
.