React Lazy Fastdom - LazyLoad Component

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.

Installation

React Lazy Load requires React 0.14 or later.

npm install --save react-lazy-fastdom

Examples

• Basic

Usage

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>
);

Props

offset

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.

offsetVertical

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.

offsetHorizontal

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.

offsetTop

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.

offsetBottom

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.

offsetLeft

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.

offsetRight

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.

throttle

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.

debounce

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.

height

Type: String|Number

The height option allows you to set the element's height even when it has no content.

width

Type: String|Number

The width option allows you to set the element's width even when it has no content.

onContentVisible

Type Function

A callback function to execute when the content appears on the screen.

container

Type Element|Window

A reference to a DOM element used for calculating visibility of LazyLoad components. The default is window.