oberonamsterdam / react-image-loading

Load an image in React with loading placeholder and fallback

React Image Loading

Load an image in React with loading placeholder and fallback, with maximum customizability.

Installation

npm i react-image-loading

Quick usage

This will render the out of the box implementation of the ImageLoading component, including a loading placeholder and fallback that have absolute positioning to fill the dimensions of the parent container. See below on how to implement custom rendering and behavior.

import { Img } from 'react-image-loading';

const MyComponent = props =>
    <div style={{minHeight: 150, position: 'relative'}}>
        <Img src={props.src} srcSet={props.srcSet} />
    </div>

Custom implementation

The out of the box Img provides a basic use case for loading images with a loading placeholder and fallback. To customize you can implement your own version of the Img component specific to your project needs. Below is an example that mimics the basic behavior of the provided Img component, but changes the color of the Fallback and LoadingPlaceholder:

import * as React from 'react';
import ImageLoading, { Fallback, LoadingPlaceholder } from 'react-image-loading';

const Img = (props) => (
    <ImageLoading>
        {(ref, status) => (
            <React.Fragment>
                {status === 'error' || !props.src
                    ? <Fallback style={{ backgroundColor: 'red'}} />
                    : <React.Fragment>
                        <img ref={ref} {...props} />
                        <LoadingPlaceholder
                            style={{ 
                                transition: 'opacity 0.5s', 
                                opacity: status === 'loading' ? 1 : 0, 
                                backgroundColor: 'blue' 
                            }}
                            animate={status === 'loading'}
                        />
                    </React.Fragment>
                }
            </React.Fragment>
        )}
    </ImageLoading>
);

export default Img;

You can also choose to create your own implementations of the Fallback and LoadingPlaceholder, or implement an entirely different logic altogether. Note: rendering the image tag with the provided ref is what triggers the loading of the image.

API

<ImageLoading>

Props

• children RenderPropsFn

RenderPropsFn

Type: Function

Params

• ref Ref
• status LoadState

Returns

React.ReactNode

Ref

Type: Function

Params

• imageElement HTMLImageElement | null

Returns

void

LoadState

The loading state of the image. Will always start at "loading", even before first render of the image, so it will immediately be put into loading state.

Type: 'loading' | 'complete' | 'error'

<LoadingPlaceholder>

Props

• style React.CSSProperties?
• animationStyle React.CSSProperties?
• animationDuration number? Loop duration in ms
• animate boolean?

<Fallback>

Props

• style React.CSSProperties?

react-image-loading's Issues

getting a warning when component is unmounted before the image was loaded

getting a warning when component is unmounted before the image was loaded

react-dom.development.js:506 Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.

need to cancel the request on componentWillUnount