js-cloudimg-responsive

v1.0.5

Published

3 years ago

Cloudimage Responsive will smartly resize, compress and accelerate images across the World in your site for all devices. The plugin supports lazy loading technique with fancy animation on image load.

Downloads

This plugin detects the width of any image container as well as the device pixel ratio density to load the optimal image size needed. Images are resized on-the-fly via the Cloudimage service, thus offering a comprehensive automated image optimization service.

When an image is first loaded on your website or mobile app, Cloudimage's resizing servers will download the origin image from the source, resize it for the client's screen size and deliver to your users through one or multiple Content Delivery Networks (CDNs). The generated image formats are cached in the CDN and will be delivered rocket fast on any subsequent request.

NOTE: Your original (master) images should be stored on a server or storage bucket (S3, Google Cloud, Azure Blob...) reachable over HTTP or HTTPS by Cloudimage. If you want to upload your master images to Cloudimage, contact us at [email protected].

Demo

To see the Cloudimage Responsive plugin in action, please check out the Demo page. Play with your browser's window size and observe your Inspector's Network tab to see how Cloudimage delivers the optimal image size to your browser, hence accelerating the overall page loading time.

Requirements

To use the Cloudimage Responsive plugin, you will need a Cloudimage token to deliver your images over CDN. Don't worry, it only takes seconds to get one by registering here. Once your token is created, you can configure it as described below. This token allows you to use 25GB of image cache and 25GB of worldwide CDN traffic per month for free.

Step 1: Installation

Add script tag with link to js-cloudimage-responsive

<script src="https://scaleflex.airstore.io/filerobot/js-cloudimage-responsive/v1.0.5.min.js"></script>

or using npm

$ npm install --save js-cloudimage-responsive

Step 2: Initialize

After adding the js-cloudimage-responsive lib, simply iniatialize it with your token and the baseUrl of your image storage:

<script>
    const ciResponsive = new window.CIResponsive({
      token: 'demo',
      baseUrl: 'https://cloudimage.public.airstore.io/demo/' // optional
    });
</script>

or in new style with npm:


import 'js-cloudimage-responsive';

const ciResponsive = new window.CIResponsive({
  token: 'demo',
  baseUrl: 'https://cloudimage.public.airstore.io/demo/' // optional
});

Step 3: Implement in img tag

Finally, just use the ci-src instead of the src attribute in image tag:

<img ci-src="magnus-lindvall.jpg" ratio="1.5"/>

NOTE: "ratio" is recommended to prevent page layout jumping. The parameter is used to calculate image height to hold the image position while image is loading.

Config

token

Type: String | Default: "demo" | required

Your Cloudimage customer token. Subscribe for a Cloudimage account to get one. The subscription takes less than a minute and is totally free.

baseUrl

Type: String | Default: "/" | optional

Your image folder on server, this alows to shorten your origin image URLs.

lazyLoading

Type: Bool | Default: false | optional

Only images close to the client's viewport will be loaded, hence accelerating the page loading time. If set to true, an additional script must be included, see Lazy loading

imgLoadingAnimation

Type: Bool | Default: true | optional

Applies a nice interlacing effect for preview transition

filters

Type: String | Default: 'n' | optional

Applies default Cloudimage filters to your image, e.g. fcontrast, fpixelate, fgaussian, backtransparent, rotation... Multiple filters can be applied, separated by "." (dot).

Full documentaiton here.

placeholderBackground

Type: String | Default: '#f4f4f4' | optional

Placeholder colored background while the image is loading

presets

Type: Object

Default:


<script>
const ciResponsive = new window.CIResponsive({
    token: 'demo',
    baseUrl: 'https://cloudimage.public.airstore.io/demo/',
    presets: {
	xs: '(max-width: 575px)', // up to 575    PHONE
	sm: '(min-width: 576px)', // 576 - 767    PHABLET
	md: '(min-width: 768px)', // 768 - 991    TABLET
	lg: '(min-width: 992px)', // 992 - 1199   SMALL_LAPTOP_SCREEN
	xl: '(min-width: 1200px)' // from 1200    USUALSCREEN
    }
});

ciResponsive.init();
</script>

Breakpoints shortcuts to use in image size property, can be overwridden.

Image properties

Cloudimage responsive plugin will make image on your page responsive if you replace the src with ci-src attribute in the <img> tag:

ci-src

Type: String | Default: undefined | required

Original image hosted on your web server. You can use absolute path or relative to baseUrl in your config.

NOTES:

The plugin uses a special algorithm to detect the width of image container and set the image size accordingly. This is the recommended way of using the Cloudimage Responsive plugin.

Images where ci-src is not used will be delivered in a standard, non-responsive way.

operation (or o)

Type: String | Default: width | optional

Operation allows to customize the behaviour of the plugin for specific images:

width - to resize with a specific width. This is useful when you want to have a fixed width, regardless of screen size.

height - to resize with a specific height. This is useful when you want to have a fixed height, regardless of screen size.

crop - to crop the image around the center

fit - to resize the image in a box and keeping the proportions of the source image

cover - to resize the image in a box without keeping the proportions of the source image

NOTES:

When you use an operation, you must specify the size for each screen size, see below

Full documentation of all operations available here

size (or s)

Type: String | Default: undefined | optional but required when using operation

Size of an image which is used as a base for creating retina ready and responsive image element.

Examples (PR - stands for your device Pixel Ratio):

[width]:

<img
  operation="width"
  ci-src="dino-reichmuth-1.jpg"
  size="250"/>

=> width: 250 * PR (px); height: auto;

[width x height]:

<img
  operation="width"
  ci-src="dino-reichmuth-1.jpg"
  size="125x200"/>

=> width: 125 * PR (px); height: 200 * PR (px);

[Width and height for different screen resolutions]:

<img
  operation="crop"
  ci-src="dino-reichmuth-1.jpg"
  size="
    sm 800x400,
    (min-width: 620px) 200x20,
    md 1000x1350,
    lg 1400x1200,
    xl 1600x1000
"/>

You can drop some breakpoints, for example:

<img
  operation="crop"
  ci-src="dino-reichmuth-1.jpg"
  size="md 1000x1350, lg 1400x1200"/>

NOTE: if size is not set, the plugin uses a special algorithm to detect the width of image container and set the image size accordingly. This is the recommended way of using the Cloudimage Responsive plugin.

For example:

<img ci-src="dino-reichmuth-1.jpg"/>

filters (or f)

Type: String | Default: none | optional

Filters allow you to modify the image's apperance and can be added on top of the resizing features above.

fgrey - apply a greyscale filter on the image

fgaussian[0..10] - apply a gaussian blur filter on the image

fcontrast[-100..100] - apply a contrast filter on the image

fbright[0..255] - apply a brightness filter on the image

fpixelate[0..100] - apply a pixelate filter on the image

fradius[0..500] - create a radius on the corners

Full documentation of all filters available here

ratio (or r)

Type: Number | optional

It is recommended to prevent page layout jumping. The parameter is used to calculate image height to hold the image position while image is loading.

To see the full cloudimage documentation click here

Lazy Loading

Lazy loading is not included into js-cloudimage-responsive by default. If you enable lazy loading in the configuration, you need to add an additional library.

The example below uses lazysizes library using Intersection Observer API.

Code Sandbox example

add the following scripts right after js-cloudimage-responsive script

<script>
  window.lazySizesConfig = window.lazySizesConfig || {};
  window.lazySizesConfig.init = false;
</script>
<script src="https://scaleflex.airstore.io/filerobot/js-cloudimage-responsive/v1.0.5.min.js"></script>
<script src="https://scaleflex.airstore.io/filerobot/js-cloudimage-responsive/lazysizes.min.js"></script>

the initialization script

<script>
    const ciResponsive = new window.CIResponsive({
      token: 'demo',
      baseUrl: 'https://cloudimage.public.airstore.io/demo/', // optional
      lazyLoading: true                                       // optional
    });

    window.lazySizes.init();
</script>

Browser support

Tested in all modern browsers and IE 11.

NOTE: If you use lazy loading with IntersectionObserver, you must manually add the IntersectionObserver polyfill for cross-browser support.