react-graceful-image

    1.5.0 • Public • Published

    React Graceful Image

    An image component for gracefully dealing with image errors, by providing optional lazy loading, optional placeholder and configurable retries on failure. Particularly useful in situations where your application might be used in poor signal areas such as when travelling on a train, a bus or a car.

    Example

    1 2 3 4
    browser broken image browser with placeholder image browser without placeholder image browser with working image after retry
    1. Default browser behaviour when image fails due to bad signal
    2. With react-graceful-image placeholder
    3. With react-graceful-image disabled placeholder
    4. With react-graceful-image retries - if the image fails to load, the package will gracefully re-attempt loading the image again

    (note: these are not mutually exclusive, for example the default behaviour makes use of both 2 & 4 together.)

    Installation

    npm install --save react-graceful-image

    Basic Usage

    <Image
        src='path_to_image'
        width='300'
        height='300'
        alt='My awesome image'
    />

    Default Behaviour

    1. Render an SVG placeholder - if environment doesn't support SVG, then avoid rendering the placeholder
    2. Check if placeholder is within the visible viewport - if so then load the image
    3. If image loads successfully - display the image by fading it in
    4. If image fails to load - retry loading the image starting with a 2 second delay and doubling it with every retry (by default retry stops after 8 tries)

    Prop Options

    Prop Description Default Type
    Any valid html image prop Any valid html image prop none valid html image prop
    placeholderColor Placeholder's color '#eee' string
    noPlaceholder Turn off placeholder rendering false bool
    customPlaceholder Provide a custom placeholder. This should be a function taking a ref and setting it on your custom placeholder so that its position could be observed within the viewport null Function returning a component
    retry Retry algorithm's configuration, consisting of count, delay and accumulate {count: 8, delay: 2, accumulate: 'multiply'} object
    onLoad Callback that will be invoked when an image loads none function
    onError Callback that will be invoked after the retry algorithm has finished and the image still hasn't been loaded none function
    noLazyLoad Turn off lazy loading false bool

    Retry

    You can modify the default retry algorithm by supplying a retry prop consisting of 3 properties: count, delay and accumulate:

    • count specifies the number of times you want to retry
    • delay specifies the delay between retries (in seconds)
    • accumulate specifies how the delay should increase with each retry, possible values: 'multiply' (default), 'add' or false (false can also be represented by simply omitting this property)

    Accumulate

    • accumulate: 'multiply' will multiply delay after each retry by the given delay value, i.e. if delay: 2 is given then 1st retry will be in 2 seconds, 2nd retry will be in 4 seconds, 3rd retry will be in 8 seconds, 4th retry will be in 16 seconds etc.
    • accumulate: 'add' will increment delay after each retry by the given delay value, i.e. if delay: 2 is given then 1st retry will be in 2 seconds, 2nd retry will be in 4 seconds, 3rd retry will be in 6 seconds, 4th retry will be in 8 seconds, etc.
    • accumulate: 'false' will keep the delay constant between retries, i.e. if delay: 2 is given then retry will run every 2 seconds

    Examples

    1: The below code snippet will display a grey placeholder until the user scrolls it into view at which point it will be lazily swapped in for the real image. If, however, the real image fails to load, then the retry algorithm is going to kick in and try loading the image again for a maximum of 8 times, with an initial delay of 2 seconds, which will then increase to 4 seconds, then to 8 seconds, then to 16 seconds, and so on (default retry configuration).

    <Image
        src='path_to_image'
        className='content-image'
        alt='My awesome image'
        onLoad={ onLoadCallback }
        onError={ onErrorCallback }
    />

    2: The below code snippet will display a grey placeholder until the user scrolls it into view at which point it will be lazily swapped in for the real image. If, however, the real image fails to load, then the retry algorithm is going to kick in and try loading the image again for a maximum of 10 times, with a fixed 2 second delay in-between each retry.

    <Image
        src='path_to_image'
        width='250'
        height='250'
        style={{ padding: '20px' }}
        alt='My awesome image'
        retry={{ count: 10, delay: 2 }}
        onLoad={ onLoadCallback }
        onError={ onErrorCallback }
    />

    3: The below code snippet will display, a custom, your own provided placeholder until the user scrolls it into view at which point it will be lazily swapped in for the real image. If, however, the real image fails to load, then the retry algorithm is going to kick in and try loading the image again for a maximum of 15 times, with initial delay of 3 seconds which will then increase to 6 seconds, then to 9 seconds, then to 12 seconds, and so on.

    <Image
        src='path_to_image'
        width='150'
        height='150'
        style={{ padding: '20px' }}
        alt='My awesome image'
        customPlaceholder={ ref => <SomePlaceholder refProp={ ref } /> }
        retry={{ count: 15, delay: 3, accumulate: 'add' }}
        onLoad={ onLoadCallback }
        onError={ onErrorCallback }
    />

    Install

    npm i react-graceful-image

    DownloadsWeekly Downloads

    2,233

    Version

    1.5.0

    License

    MIT

    Unpacked Size

    19.4 kB

    Total Files

    5

    Last publish

    Collaborators

    • linasmnew