React
Use TwicPics React Components to get images and videos integration best practices out-of-the-box.
You can find usage examples in our online demo project.
Installation
Add the @twicpics/components
package to your project:
# Using yarn
yarn add @twicpics/components
# Or using npm
npm install @twicpics/components
Setup
React
project
Setting-up TwicPics Components into your While we recommend going the ES module
route and use import
statements, TwicPics Components is also backward compatible with CommonJS
and require
statements.
Add the import part
// import TwicPics react components
import { installTwicPics } from '@twicpics/components/react'
// import TwicPics components css
import '@twicpics/components/style.css'
and the configuration part (see Setup Options)
installTwicPics({
// domain is mandatory
domain: 'https://<your-domain>.twic.pics',
})
into the app startup of your React
project.
index.jsx (React 16+)
// Here is an example of a `React 16+` app startup configured with TwicPics.
import React from 'react'
import ReactDOM from 'react-dom'
import Root from './root.jsx'
// TwicPics Components importation
import { installTwicPics } from '@twicpics/components/react'
import '@twicpics/components/style.css'
// TwicPics Components configuration (see Setup Options)
installTwicPics({
// domain is mandatory
domain: 'https://<your-domain>.twic.pics',
})
ReactDOM.render(
<React.StrictMode>
<Root />
</React.StrictMode>,
document.getElementById('root')
)
index.jsx (React 18+)
// Here is an example of a `React 18+` app startup configured with TwicPics.
import React from 'react'
import { createRoot } from 'react-dom/client'
import Root from './root.jsx'
// TwicPics Components importation
import { installTwicPics } from '@twicpics/components/react'
import '@twicpics/components/style.css'
// TwicPics Components configuration (see Setup Options)
installTwicPics({
// domain is mandatory
domain: 'https://<your-domain>.twic.pics',
})
const container = document.getElementById('root')
const root = createRoot(container)
root.render(<Root />)
Setup Options
Option | Description | Type | Default |
---|---|---|---|
anticipation | TwicPics will lazy-load images by default. To avoid too abrupt a transition with elements appearing into view and then images very obviously loading afterwards, TwicPics will "anticipate" lazy loading by a factor of the actual viewport. This behavior is controlled by this setting. | Number | 0.2 |
domain | This is your very own TwicPics domain. Providing it is mandatory. | String | |
env | Can be debug , offline or production . When set to debug , a gray lightweight svg placeholder that displays its intrinsic dimensions is displayed in place of all medias targeted by their src value. When set to offline , these medias are replaced by a simple placeholder that allows to visualise their display area. | String | "production" |
handleShadowDom | Must be set to true when using TwicComponents within a shadow DOM. | boolean | false |
maxDPR | TwicPics will take the "Device Pixel Ratio" (DPR ) of the current device into consideration when determining the sizes of images to load. By default, it will not take a DPR greater than 2 into consideration. If the DPR of the device is higher than 2 , TwicPics will assume it to be 2 . Using maxDPR , you can lower this limit down to 1 or be more permissive (for instance by setting it to 3 or 4 ). | Number | 2 |
path | Path to prepend to all src attributes. For instance, if path is "some/folder" then a src attribute set to "image.jpg" will be expanded into "some/folder/image.jpg" | String | |
step | To avoid requesting too may variants of the same image, TwicPics will round the width of images to the closest multiple of step. The height will then be computed in order to respect the original aspect ratio. | Integer | 10 |
Usage
Import TwicPics Components TwicImg
and TwicVideo
in your template files and use them in place of img
or video
tags.
Add the import part
// this component will be used in place of an img element.
import { TwicImg } from '@twicpics/components/react'
// this component will be used in place of an video element.
import { TwicVideo } from '@twicpics/components/react'
then, use <TwicImg>
or <TwicVideo>
in place of standard tags <img>
or <video>
(see Components Properties).
Basic usage
NB : TwicPics Components can also be used in js
, jsx
, ts
, tsx
files.
// component.jsx
import React from 'react'
import { TwicImg } from '@twicpics/components/react'
const YourTemplate = () => <TwicImg src="path/to/your/image" />
export default YourTemplate
Bulk loading with TwicView
By default, <TwicImg>
and <TwicVideo>
will only start loading when they come into the viewport. But sometimes, you may want to load multiple assets in bulk instead of lazy loading them. This is where <TwicView>
comes into play.
The <TwicView>
components eager loads all of his <TwicImg>
and <TwicVideo>
children as soon as it comes into the viewport (depending on your anticipation settings.)
For example, if you're building a carousel, you might want to bulk load all images. In the following code, all three images will be loaded when TwicView
comes into the viewport:
<TwicView>
<TwicImg src="image1.jpg" />
<TwicImg src="image2.jpg" />
<TwicImg src="image3.jpg" />
</TwicView>
Style-Driven Approach
You can set up components using pure CSS and the power of CSS variables
styles.css
.landscape {
--twic-ratio: calc(4 / 3);
}
.portrait {
--twic-ratio: calc(3 / 4);
}
.square {
--twic-ratio: calc(1);
}
.contain {
--twic-mode: contain;
}
.cover {
--twic-mode: cover;
}
.left {
--twic-position: left;
}
.right {
--twic-position: right;
}
.lg {
width: 300px;
}
.md {
width: 150px;
}
.sm {
width: 100px;
}
<!-- component.jsx -->
<div className="landscape">
<TwicImg src=path/to/your/image></TwicImg>
</div>
<div className="square">
<TwicImg src=path/to/your/image></TwicImg>
</div>
<div className="portrait">
<TwicImg src=path/to/your/image></TwicImg>
</div>
<div className="contain left">
<TwicImg src=path/to/your/image ratio="16/9"></TwicImg>
</div>
<div className="contain right">
<TwicImg src=path/to/your/image ratio="16/9"></TwicImg>
</div>
<!---
Attributes take precedence over CSS.
In the next example, ratio will 16/9 AND NOT 1 as defined in square css class
--->
<div className="cover square">
<TwicImg src=path/to/your/image ratio="16/9"></TwicImg>
</div>
Responsive Example
Setting up components using CSS and CSS variables enables hassle-free responsive designs.
styles.css
.style-driven {
--twic-ratio: 1.9;
}
@media (min-width: 640px) {
.style-driven {
--twic-mode: contain;
}
}
@media (min-width: 768px) {
.style-driven {
--twic-mode: cover;
--twic-ratio: calc(4 / 3);
}
}
@media (min-width: 1024px) {
.style-driven {
--twic-ratio: calc(16 / 9);
}
}
@media (min-width: 1280px) {
.style-driven {
--twic-ratio: calc(21 / 9);
}
}
@media (min-width: 1536px) {
.style-driven {
--twic-ratio: calc(36 / 9);
}
}
Your template features a single component that will follow your CSS directives and behave responsively.
<!-- component.jsx -->
<TwicImg className="style-driven" src="path/to/your/image"></TwicImg>
Working with ratio="none"
Particularly useful when creating hero banner, you can specify the height of your image while respecting its natural aspect ratio and optimizing your Cumulative Layout Shift (CLS) metric.
styles.css
/* You are responsible for properly sizing the component. */
.hero-image {
height: 500px;
}
@media (min-width: 1024px) {
.hero-image {
height: 300px;
width: 100%;
}
}
<!-- component.jsx -->
<TwicImg src="path/to/your/image" className="hero-image" ratio="none"></TwicImg>
Lifecycle
Passing a callback function to onStateChange
gives access to the loading state of your image or video.
Here are the values the Component will emit (see State Type definition) :
new
: when theimg
orvideo
source has not started loadingloading
: when theimg
orvideo
source is loadingdone
: when theimg
orvideo
source has successfully loadederror
: when an error occurred while loading theimg
orvideo
source
// component.jsx
const [state, setState] = useState(undefined)
const handleStateChange = (stateEvent) => {
// Implement the logic here
const { state } = stateEvent
console.log(`TwicComponent emits a new state`, state)
setState(state)
}
return <TwicImg onStateChange={handleStateChange} src="path/to/your/image" />
Image magnifier
The <TwicImg>
component allows to display a lazy loaded zoomed version of your image on mouse over.
To activate the zoom feature, simply set the zoom
property to a number strictly greater than 1. This number represents the magnification factor of your image.
For example:
<TwicImg src="image1.jpg" zoom="2" /> <TwicImg src="image2.jpg" zoom="2.5" />
The zoom factor can also be configured through the --twic-zoom
CSS variable.
To activate the style-driven zoom, simply set zoom
property to'css'
and add a new rule to your stylesheet.
For example:
<TwicImg src="image3.jpg" zoom="css" className=".zoom-3" />
.zoom-3 {
--twic-zoom: 3;
}
It applies only to TwicImg
component in cover mode
.
Components Properties
TwicImg
This component can be used in place of an img
element.
<TwicImg
src="<path>"
alt="<String>"
anchor="<String>"
bot="<String>"
eager="<boolean>"
focus="<auto|coordinates>"
intrinsic="<String>"
mode="<contain|cover>"
onStateChange="<function>"
position="<css position>"
placeholder="<preview|maincolor|meancolor|none>"
preTransform="<String>"
ratio="<ratio>"
step="<integer>"
title="<String>"
transition="<fade|zoom|none>"
transitionDelay="<String>"
transitionDuration="<String>"
transitionTimingFunction="<String>"
zoom="<String | Number>"
/>
Attribute | Description | Type | Default |
---|---|---|---|
alt | alt attribute content | String | based on src |
anchor | Positions the image in both contain and cover mode. Accepted values are top , bottom , left , right , top-left , top-right , bottom-left , bottom-right and center . position and focus take precedence in contain and cover mode respectively. Please note that anchor is applied after an eventual preTransform . | String | |
bot | A slash-separated list of TwicPics API transformations to be performed for search engine bots. This overrides all other transformations when provided, even if empty (i.e bot="" ). See the TwicPics bot attribute documentation for more information. | String | |
eager | Load the image as soon as the component is mounted. This effectively means disabling lazy loading for this image. | boolean | false |
focus | Sets the focus point in cover mode. focus takes precedence over anchor when both are provided. See the TwicPics focus attribute documentation for more information. Only use this attribute if you need a specific focus point or if you want to leverage smart cropping with focus="auto" : if you only need border-based positionning (top , bottom , left , right , etc), use anchor instead. | String | |
onStateChange | A callback function triggered each time the asset loading state is updated. State can be new , loading , done or error . | ( stateEvent: StateEvent ) => void | |
intrinsic | Dimensions in pixels of the original image, formatted <width>x<height> (eg. 1920x1080). It prevents image upscaling and limits the number of generated variants. If using preTransform , you should specify the intrinsic dimensions of the resulting image. Using incorrect values can lead to display issues, see the intrinsic attribute documentation. | String | |
mode | Can be contain or cover and determines if the image fills the area and is cropped accordingly (cover ) or if the image will sit inside the area with no cropping (contain ). | String | cover |
placeholder | Can be preview , meancolor , maincolor or none . See the TwicPics output transformation documentation for more information. Setting will be overridden to none when using zoom transition . | String | preview |
position | Positions the image in contain mode. position takes precedence over anchor when both are provided. Syntax is the same as for CSS position properties background-position and object-position . Only use this attribute if you need precise positionning: if you only need border-based positionning (top , bottom , left , right , etc), use anchor instead. | String | center |
preTransform | A slash-separated list of TwicPics API transformations to be performed before resizing the image (see the TwicPics Manipulation documentation). Note that anchor and focus are applied after preTransform : if you need to specify a specific focus point for your preTransform then it needs to be part of the expression (like preTransform="focus=auto/crop=50px50p" for instance). Be aware that using this option can lead to unexpected results so use with caution! | String | |
ratio | A unitless width/height or width:height value pair (as in 4/3 or 4:3 ) that defines the aspect ratio of the display area. If height is not specified, it is assumed to be 1 . A square area will be created by default. When set to none , ratio is determined based on width and height as computed by the browser following your CSS definitions. The --twic-ratio CSS variable is ignored in this instance. You are responsible for properly sizing the component when ratio="none" . | String or number | 1 |
src | Path to the image. When not provided, a red lightweight svg placeholder that displays its intrinsic dimensions is displayed in place of the absent image. When env is set to offline , that red lightweight svg is replaced by a simple red placeholder. | String | |
step | See the TwicPics step attribute documentation for more information. | Integer | 10 |
title | title representing information related to the image. See global attribute title . | String | |
transition | Determines how the image will be revealed once loaded. With a fade in effect (fade ), a zoom effect (zoom ) or without any transition (none ). Unsupported values are handled as fade . | String | fade |
transitionDuration | Duration of the transition effect. | String | 400ms |
transitionTimingFunction | CSS timing function applied to the transition effect. | String | ease |
transitionDelay | Transition delay of the transition effect. | String | 0ms |
zoom | Enables zoom feature and sets the magnification factor. Must be a number strictly greater than 1 as in "1.5" or 1.5 . When set to 'css' magnification factor is defined through the CSS variable --twic-zoom . Should only be applied to images in cover mode . See Image magnifier. | `String | number` |
TwicVideo
This component can be used in place of a video
element.
<TwicVideo
src="<path>"
anchor="<String>"
bot="<String>"
duration="<String|number>"
eager="<boolean>"
from="<String|number>"
focus="<auto|coordinates>"
intrinsic="<String>"
mode="<contain|cover>"
position="<css position>"
posterFrom="<String|number>"
placeholder="<preview|maincolor|meancolor|none>"
preTransform="<String>"
ratio="<ratio>"
(stateChangeEvent)="<function>"
step="<integer>"
title="<String>"
to="<String|number>"
transition="<fade|zoom|none>"
transitionDelay="<String>"
transitionDuration="<String>"
transitionTimingFunction="<String>"
/>
Attribute | Description | Type | Default |
---|---|---|---|
anchor | Positions the video in both contain and cover mode. Accepted values are top , bottom , left , right , top-left , top-right , bottom-left , bottom-right and center . position and focus take precedence in contain and cover mode respectively. Please note that anchor is applied after an eventual preTransform . | String | |
bot | A slash-separated list of TwicPics API transformations to be performed for search engine bots. This overrides all other transformations when provided, even if empty (i.e bot="" ). See the TwicPics bot attribute documentation for more information. | String | |
duration | Limits the duration of the video. duration is expressed in seconds and must be a positive number. duration will not move the starting point of the video: to do so, you'll have to use the from property. See duration documentation. | String or number | |
eager | Load the video as soon as the component is mounted. This effectively means disabling lazy loading for this video. | boolean | false |
focus | Sets the focus point in cover mode. focus takes precedence over anchor when both are provided. See the TwicPics focus attribute documentation for more information. Only use this attribute if you need a specific focus point or if you want to leverage smart cropping with focus="auto" : if you only need border-based positionning (top , bottom , left , right , etc), use anchor instead. | String | |
from | Moves the starting point of the video. from is expressed in seconds and must be a positive number. from will not move the end point of the video: to do so, you'll have to use the duration or to properties. See from documentation. See from documentation. | String or number | |
intrinsic | Dimensions in pixels of the original video, formatted <width>x<height> (eg. 1920x1080). It prevents video upscaling and limits the number of generated variants. If using preTransform , you should specify the intrinsic dimensions of the resulting video. Using incorrect values can lead to display issues, see the intrinsic attribute documentation. | String | |
mode | Can be contain or cover and determines if the video fills the area and is cropped accordingly (cover ) or if the video will sit inside the area with no cropping (contain ). | String | cover |
placeholder | Can be preview , meancolor , maincolor or none . See the TwicPics output transformation documentation for more information. Setting will be overridden to none when using zoom transition . | String | preview |
position | Positions the video in contain mode. position takes precedence over anchor when both are provided. Syntax is the same as for CSS position properties background-position and object-position . Only use this attribute if you need precise positionning: if you only need border-based positionning (top , bottom , left , right , etc), use anchor instead. | String | center |
posterFrom | Determines which frame of the source video should be used as a poster / preview. posterFrom is expressed in seconds and must be a positive number. By default posterFrom is equal to 0, meaning the very first frame of the video is used. posterFrom will not modify the video in any way: to do so, you'll have to use the duration , from or to properties. | String or number | |
preTransform | A slash-separated list of TwicPics API transformations to be performed before resizing the video (see the TwicPics Manipulation documentation). Note that anchor and focus are applied after preTransform : if you need to specify a specific focus point for your preTransform then it needs to be part of the expression (like preTransform="focus=auto/crop=50px50p" for instance). Be aware that using this option can lead to unexpected results so use with caution! | String | |
ratio | A unitless width/height or width:height value pair (as in 4/3 or 4:3 ) that defines the aspect ratio of the display area. If height is not specified, it is assumed to be 1 . A square area will be created by default. When set to none , ratio is determined based on width and height as computed by the browser following your CSS definitions. The --twic-ratio CSS variable is ignored in this instance. You are responsible for properly sizing the component when ratio="none" . | String or number | 1 |
src | Path to the video. When not provided, a red lightweight svg placeholder that displays its intrinsic dimensions is displayed in place of the absent video. When env is set to offline , that red lightweight svg is replaced by a simple red placeholder. | String | |
stateChangeEvent | An event emitter triggered each time the asset loading state is updated. State can be new , loading , done or error . | EventEmitter<StateEvent> | |
step | See the TwicPics step attribute documentation for more information. | Integer | 10 |
title | title representing information related to the video. See global attribute title . | String | |
to | Moves the end point of the video. to is expressed in seconds and must be a positive number. to will not move the starting point of the video: to do so, you'll have to use the from property. See to documentation. | String or number | |
transition | Determines how the video will be revealed once loaded. With a fade in effect (fade ), a zoom effect (zoom ) or without any transition (none ). Unsupported values are handled as fade . | String | fade |
transitionDuration | Duration of the transition effect. | String | 400ms |
transitionTimingFunction | CSS timing function applied to the transition effect. | String | ease |
transitionDelay | Transition delay of the transition effect. | String | 0ms |
Loading State Values
Union type for all possible image or video loading state.
type State = `error` | `done` | `loading` | `new`
new
: when theimg
orvideo
source has not started loadingloading
: when theimg
orvideo
source is loadingdone
: when theimg
orvideo
source has successfully loadederror
: when an error occurred while loading theimg
orvideo
source
State Change Event
Data type passed as parameter to onStateChange
function.
export type StateEvent = {
target: TwicImg | TwicVideo
state: State
}
CSS Variables
List of variables that can be used to configure your components using pure CSS.
<selector > {
--twic-ratio: <ratio>;
--twic-mode: <contain|cover>;
--twic-position: <css position>;
--twic-transition-delay: <string>;
--twic-transition-duration: <string>;
--twic-transition-timing-function: <string>;
--twic-zoom: <number>;
}
Each CSS variable corresponds to one of the components attributes listed in the Components Properties section. If present, the attribute takes precedence over the corresponding CSS variable.
Variable | Description | HTML Attribute | Default |
---|---|---|---|
--twic-mode | Can be contain or cover and determines if the image fills the area and is cropped accordingly (cover ) or if the image will sit inside the area with no cropping (contain ). | mode | cover |
--twic-position | Only useful in contain mode. Locates the image inside the area. Syntax is the same as for CSS position properties like background-position or object-position. Useful values are top , bottom , left , right , left top , left bottom and so on. | position | center |
--twic-ratio | Floating point value corresponding to a unitless width/height ratio (as in calc(4/3) or 1.333 ). Ratio will correspond to a square area by default. | ratio | 1 |
--twic-transition-delay | Transition delay of the transition effect. | transitionDelay | 0ms |
--twic-transition-duration | Duration of the transition effect. | transitionDuration | 400ms |
--twic-transition-timing-function | CSS timing function applied to the transition effect. | transitionTimingFunction | ease |
--twic-zoom | Strictly greater than 1 floating point value corresponding to the zoom factor to be applied. Only applies to TwicImg with zoom property set to 'css' . | number |
Feedback and support
TwicPics Components are open-source on GitHub. For features requests and bugs, open an issue. The TwicPics team also remains available for support via the live chat (at the bottom right.)