Research
Security News
Malicious npm Packages Inject SSH Backdoors via Typosquatted Libraries
Socket’s threat research team has detected six malicious npm packages typosquatting popular libraries to insert SSH backdoors.
styled-jsx
Advanced tools
The styled-jsx npm package is a CSS-in-JS library that allows you to write encapsulated and scoped CSS to style your components in a React application. It is specifically designed to work with React and Next.js and provides a way to include styles directly within JavaScript or TypeScript files.
Scoped Styles
This feature allows you to write CSS that is scoped to a component. The styles will not leak to other parts of the application.
<style jsx>{`p { color: red; }`}</style>
Global Styles
With styled-jsx, you can also define global styles that apply to the entire application, not just scoped to a single component.
<style jsx global>{`body { background: black; }`}</style>
Dynamic Styles
styled-jsx supports dynamic styles, allowing you to use JavaScript variables and expressions to determine the styles at runtime.
`<style jsx>{
`p { color: ${color}; }`
}</style>`
Preprocessing
You can use preprocessors with styled-jsx to include external stylesheets or use features like nesting or variables.
<style jsx>{`
@import 'styles/shared.css';
p { color: red; }
`}</style>
styled-components is another CSS-in-JS library that allows you to use template literals to write actual CSS code in your JavaScript files. It also handles scoping and supports dynamic styling. It differs from styled-jsx in its API and the way styles are applied to components.
Emotion is a performant and flexible CSS-in-JS library. It allows you to style applications quickly with string or object styles. It has a similar API to styled-components and includes features like composition, theming, and server-side rendering.
Linaria is a zero-runtime CSS-in-JS library that extracts CSS to separate files during the build process, rather than including styles in the JavaScript bundle. This can result in better performance compared to styled-jsx, which includes styles in the JS bundle.
Full, scoped and component-friendly CSS support for JSX (rendered on the server or the client).
Code and docs are for v3 which we highly recommend you to try. Looking for styled-jsx v2? Switch to the v2 branch.
Firstly, install the package:
npm install --save styled-jsx
Next, add styled-jsx/babel
to plugins
in your babel configuration:
{
"plugins": ["styled-jsx/babel"]
}
Now add <style jsx>
to your code and fill it with CSS:
export default () => (
<div>
<p>only this paragraph will get the style :)</p>
{/* you can include <Component />s here that include
other <p>s that don't get unexpected styles! */}
<style jsx>{`
p {
color: red;
}
`}</style>
</div>
)
The following are optional settings for the babel plugin.
optimizeForSpeed
Blazing fast and optimized CSS rules injection system based on the CSSOM APIs.
{
"plugins": [["styled-jsx/babel", { "optimizeForSpeed": true }]]
}
When in production* this mode is automatically enabled.
Beware that when using this option source maps cannot be generated and styles cannot be edited via the devtools.
* process.env.NODE_ENV === 'production'
sourceMaps
Generates source maps (default: false
)
styleModule
Module that the transpiled files should import (default: styled-jsx/style
)
vendorPrefixes
Turn on/off automatic vendor prefixing (default: true
)
Next.js automatically configures styled-jsx
with babel or swc, you don't have to configure it manually.
The example above transpiles to the following:
import _JSXStyle from 'styled-jsx/style'
export default () => (
<div className="jsx-123">
<p className="jsx-123">only this paragraph will get the style :)</p>
<_JSXStyle id="123">{`p.jsx-123 {color: red;}`}</_JSXStyle>
</div>
)
Unique classnames give us style encapsulation and _JSXStyle
is heavily optimized for:
Notice that the outer <div>
from the example above also gets a jsx-123
classname. We do this so that
you can target the "root" element, in the same manner that
:host
works with Shadow DOM.
If you want to target only the host, we suggest you use a class:
export default () => (
<div className="root">
<style jsx>{`
.root {
color: green;
}
`}</style>
</div>
)
To skip scoping entirely, you can make the global-ness of your styles explicit by adding global.
export default () => (
<div>
<style jsx global>{`
body {
background: red;
}
`}</style>
</div>
)
The advantage of using this over <style>
is twofold: no need
to use dangerouslySetInnerHTML
to avoid escaping issues with CSS
and take advantage of styled-jsx
's de-duping system to avoid
the global styles being inserted multiple times.
Sometimes it's useful to skip selectors scoping. In order to get a one-off global selector we support :global()
, inspired by css-modules.
This is very useful in order to, for example, generate a global class that
you can pass to 3rd-party components. For example, to style
react-select
which supports passing a custom class via optionClassName
:
import Select from 'react-select'
export default () => (
<div>
<Select optionClassName="react-select" />
<style jsx>{`
/* "div" will be prefixed, but ".react-select" won't */
div :global(.react-select) {
color: red;
}
`}</style>
</div>
)
To make a component's visual representation customizable from the outside world there are three options.
Any value that comes from the component's render
method scope is treated as dynamic. This makes it possible to use props
and state
for example.
const Button = props => (
<button>
{props.children}
<style jsx>{`
button {
padding: ${'large' in props ? '50' : '20'}px;
background: ${props.theme.background};
color: #999;
display: inline-block;
font-size: 1em;
}
`}</style>
</button>
)
New styles' injection is optimized to perform well at runtime.
That said when your CSS is mostly static we recommend to split it up in static and dynamic styles and use two separate style
tags so that, when changing, only the dynamic parts are recomputed/rendered.
const Button = props => (
<button>
{props.children}
<style jsx>{`
button {
color: #999;
display: inline-block;
font-size: 2em;
}
`}</style>
<style jsx>{`
button {
padding: ${'large' in props ? '50' : '20'}px;
background: ${props.theme.background};
}
`}</style>
</button>
)
className
togglingThe second option is to pass properties that toggle class names.
const Button = props => (
<button className={'large' in props && 'large'}>
{props.children}
<style jsx>{`
button {
padding: 20px;
background: #eee;
color: #999;
}
.large {
padding: 50px;
}
`}</style>
</button>
)
Then you would use this component as either <Button>Hi</Button>
or <Button large>Big</Button>
.
style
*best for animations
Imagine that you wanted to make the padding in the button above completely customizable. You can override the CSS you configure via inline-styles:
const Button = ({ padding, children }) => (
<button style={{ padding }}>
{children}
<style jsx>{`
button {
padding: 20px;
background: #eee;
color: #999;
}
`}</style>
</button>
)
In this example, the padding defaults to the one set in <style>
(20
), but the user can pass a custom one via <Button padding={30}>
.
It is possible to use constants like so:
import { colors, spacing } from '../theme'
import { invertColor } from '../theme/utils'
const Button = ({ children }) => (
<button>
{children}
<style jsx>{`
button {
padding: ${spacing.medium};
background: ${colors.primary};
color: ${invertColor(colors.primary)};
}
`}</style>
</button>
)
Please keep in mind that constants defined outside of the component scope are treated as static styles.
styled-jsx
v5 introduced StyledRegistry
component and useStyleRegistry
hook to let you scope styles rendering in each SSR render to keep concurrent-safe.
registry.styles()
will return the array of react components for style tags.registry.flush()
can clean the existing styles in the registry, it's optional for SSR when you have a standalone registry for each SSR render.Next.js 12 integrates with
styled-jsx
v5 and manages the registry for you.
import React from 'react'
import ReactDOM from 'react-dom/server'
import { StyleRegistry, useStyleRegistry } from 'styled-jsx'
import App from './app'
function Styles() {
const registry = useStyleRegistry()
const styles = registry.styles()
return <>{styles}</>
}
export default (req, res) => {
const app = ReactDOM.renderToString(<App />)
const html = ReactDOM.renderToStaticMarkup(
<StyleRegistry>
<html>
<head>
<Styles />
</head>
<body>
<div id="root" dangerouslySetInnerHTML={{ __html: app }} />
</body>
</html>
</StyleRegistry>
)
res.end('<!doctype html>' + html)
}
There's also a new API createStyleRegistry
that is introduced when you have to create a registry manually. In this way you can operate the registry yourself to extract the rendered styles (registry.styles()
) or flush them out (registry.flush()
).
const registry = createStyleRegistry()
const styles = registry.styles() // access styles
function Page() {
return (
<StyleRegistry registry={registry}>
<App />
</StyleRegistry>
)
}
By default <StyleRegistry />
will use the registry
from root top StyleRegistry
, which means there's only one registry
in the react tree.
It's paramount that you use one of these two functions so that the generated styles can be diffed when the client loads and duplicate styles are avoided.
Strict CSP is supported.
You should generate a nonce per request.
import nanoid from 'nanoid'
const nonce = Buffer.from(nanoid()).toString('base64') //ex: N2M0MDhkN2EtMmRkYi00MTExLWFhM2YtNDhkNTc4NGJhMjA3
You must then pass a nonce to registry.styles({ nonce })
and set a <meta property="csp-nonce" content={nonce} />
tag.
Your CSP policy must share the same nonce as well (the header nonce needs to match the html nonce and remain unpredictable).
Content-Security-Policy: default-src 'self'; style-src 'self' 'nonce-N2M0MDhkN2EtMmRkYi00MTExLWFhM2YtNDhkNTc4NGJhMjA3';
In styled-jsx styles can be defined outside of the component's render method or in separate JavaScript modules using the styled-jsx/css
library. styled-jsx/css
exports three tags that can be used to tag your styles:
css
, the default export, to define scoped styles.css.global
to define global styles.css.resolve
to define scoped styles that resolve to the scoped className
and a styles
element.In an external file:
/* styles.js */
import css from 'styled-jsx/css'
// Scoped styles
export const button = css`
button {
color: hotpink;
}
`
// Global styles
export const body = css.global`body { margin: 0; }`
// Resolved styles
export const link = css.resolve`a { color: green; }`
// link.className -> scoped className to apply to `a` elements e.g. jsx-123
// link.styles -> styles element to render inside of your component
// Works also with default exports
export default css`
div {
color: green;
}
`
You can then import and use those styles:
import styles, { button, body } from './styles'
export default () => (
<div>
<button>styled-jsx</button>
<style jsx>{styles}</style>
<style jsx>{button}</style>
<style jsx global>
{body}
</style>
</div>
)
N.B. All the tags except for resolve
don't support dynamic styles.
resolve
and global
can also be imported individually:
import { resolve } from 'styled-jsx/css'
import { global } from 'styled-jsx/css'
If you use Prettier we recommend you to use the default css
export syntax since the tool doesn't support named imports.
The css
tag from styled-jsx/css
can be also used to define styles in your components files but outside of the component itself. This might help with keeping render
methods smaller.
import css from 'styled-jsx/css'
export default () => (
<div>
<button>styled-jsx</button>
<style jsx>{button}</style>
</div>
)
const button = css`
button {
color: hotpink;
}
`
Like in externals styles css
doesn't work with dynamic styles. If you have dynamic parts you might want to place them inline inside of your component using a regular <style jsx>
element.
resolve
tagThe resolve
tag from styled-jsx/css
can be used when you need to scope some CSS - for example, if you need to style nested components from the parent, such as the Link
component in the example below.
It works by returning the generated scoped className
and related styles
.
import React from 'react'
import Link from 'some-library'
import css from 'styled-jsx/css'
const { className, styles } = css.resolve`
a { color: green }
`
export default () => (
<div>
{/* use the className */}
<Link className={className}>About</Link>
{/* render the styles for it */}
{styles}
</div>
)
The resolve
tag also supports dynamic styles, via template string interpolation:
import React from 'react'
import css from 'styled-jsx/css'
function getLinkStyles(color) {
return css.resolve`
a { color: ${color} }
`
}
export default props => {
const { className, styles } = getLinkStyles(props.theme.color)
return (
<div>
<Link className={className}>About</Link>
{styles}
</div>
)
}
resolve
as a Babel macroIf you can't (or would rather not) make changes to your .babelrc
, the resolve
tag can be used as a Babel macro, thanks to the babel-plugin-macros
system.
To set this up, first of all, install styled-jsx
and babel-plugin-macros
:
npm i --save styled-jsx
npm i --save-dev babel-plugin-macros
Next, add babel-plugin-macros
to your Babel configuration:
{
"plugins": ["babel-plugin-macros"]
}
You can then use resolve
by importing it from styled-jsx/macro
.
import css from 'styled-jsx/macro'
const { className, styles } = css.resolve`
a { color: green }
`
export default () => (
<div>
<Link className={className}>About</Link>
{styles}
</div>
)
create-react-app
Create React App comes with babel-plugin-macros
already installed, so the only thing that needs to be done is to install styled-jsx
:
npm i --save styled-jsx
Then resolve
can be imported from styled-jsx/macro
and used the same way as in the example in the Using resolve
as a Babel macro section above.
styled-jsx v3 comes with a webpack loader that lets you write styles in regular css
files and consume them in React.
import styles from '../components/button/styles.css'
export default () => (
<div>
<button>styled-jsx</button>
<style jsx>{styles}</style>
</div>
)
To consume the styles in your component you can import them from your CSS file and render them using a <style jsx>
tag. Remember to add the global
prop if you want your styles to be global.
To use this feature you need to register the loader in your webpack config file, before babel-loader
which will then transpile the styles via styled-jsx/babel
config: {
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: require('styled-jsx/webpack').loader,
options: {
type: 'scoped'
}
}
]
}
]
}
}
The plugin accepts a type
option to configure whether the styles should be scoped
, global
or resolve
(see above). By default its values is set to scoped
. type
can also be a function
which takes the fileName
and the fileNameQuery
that is being transpiled and must return a valid type.
type validTypes = 'scoped' | 'global' | 'resolve'
type fileName = string
type Options = {|
type: validTypes | ((fileName, options) => validTypes)
|}
import styles from './styles.css?type=global'
// webpack
config: {
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: require('styled-jsx/webpack').loader,
options: {
type: (fileName, options) => options.query.type || 'scoped'
}
}
]
}
]
}
}
The type can also be set per individual CSS file via CSS comment:
/* @styled-jsx=scoped */
button {
color: red;
}
The CSS comment option will override the one in the webpack configuration only for this specific file.
Example of next.config.js
to integrate styled-jsx/webpack
:
module.exports = {
webpack: (config, { defaultLoaders }) => {
config.module.rules.push({
test: /\.css$/,
use: [
defaultLoaders.babel,
{
loader: require('styled-jsx/webpack').loader,
options: {
type: 'scoped'
}
}
]
})
return config
}
}
Styles can be preprocessed via plugins.
Plugins are regular JavaScript modules that export a simple function with the following signature:
function plugin(css: string, options: Object): string
Basically they accept a CSS string in input, optionally modify it and finally return it.
Plugins make it possible to use popular preprocessors like SASS, Less, Stylus, PostCSS or apply custom transformations to the styles at compile time.
To register a plugin add an option plugins
for styled-jsx/babel
to your .babelrc
. plugins
must be an array of module names or full paths for local plugins.
{
"plugins": [
[
"styled-jsx/babel",
{
"plugins": [
"my-styled-jsx-plugin-package",
"/full/path/to/local/plugin"
]
}
]
]
}
{
"presets": [
[
"next/babel",
{
"styled-jsx": {
"plugins": ["styled-jsx-plugin-postcss"]
}
}
]
]
}
This is a fairly new feature so make sure that you using a version of Next.js that supports passing options to styled-jsx
.
Plugins are applied in definition order left to right before styles are scoped.
In order to resolve local plugins paths you can use NodeJS' require.resolve.
N.B. when applying the plugins styled-jsx replaces template literals expressions with placeholders because otherwise CSS parsers would get invalid CSS E.g.
/* `ExprNumber` is a number */
%%styled-jsx-placeholder-ExprNumber%%
Plugins won't transform expressions (eg. dynamic styles).
When publishing a plugin you may want to add the keywords: styled-jsx
and styled-jsx-plugin
.
We also encourage you to use the following naming convention for your plugins:
styled-jsx-plugin-<your-plugin-name>
Users can set plugin options by registering a plugin as an array that contains the plugin path and an options object.
{
"plugins": [
[
"styled-jsx/babel",
{
"plugins": [
["my-styled-jsx-plugin-package", { "exampleOption": true }]
],
"sourceMaps": true
}
]
]
}
Each plugin receives a options
object as second argument which contains
the babel and user options:
;(css, options) => {
/* ... */
}
The options
object has the following shape:
{
// user options go here
// eg. exampleOption: true
// babel options
babel: {
sourceMaps: boolean,
vendorPrefixes: boolean,
isGlobal: boolean,
filename: ?string, // defined only when the filename option is passed to Babel, such as when using Babel CLI or Webpack
location: { // the original location of the CSS block in the JavaScript file
start: {
line: number,
column: number,
},
end: {
line: number,
column: number,
}
}
}
}
The following plugins are proof of concepts/sample:
If you're using a tool such as Enzyme, you might want to avoid compiling your styles in test renders. In general, styled-jsx artifacts like jsx-123
classnames and vendor prefixing are not direct concerns of your component, and they generate a lot of snapshot noise.
One option is to exclude the styled-jsx/babel
plugin from the test
environment using env
in your Babel config (see Config Merging options).
But this can cause noise in your terminal output when rendering:
console.error node_modules/react-dom/cjs/react-dom.development.js:527
Warning: Received `true` for a non-boolean attribute `jsx`.
The styled-jsx/babel-test
solves this problem. It simply strips jsx
attributes from all <style>
tags. Be sure to target each environment with the appropriate plugin:
{
"env": {
"production": {
"plugins": ["styled-jsx/babel"]
},
"development": {
"plugins": ["styled-jsx/babel"]
},
"test": {
"plugins": ["styled-jsx/babel-test"]
}
}
}
When using styled-jsx/babel-test
, styled-jsx/css
throws the following error:
styled-jsx/css: if you are getting this error it means that your `css` tagged template literals were not transpiled.
to solve this issue you need to mock styled-jsx/css
. You can find a guide at the following link https://kevinjalbert.com/jest-snapshots-reducing-styled-jsx-noise/
jsx
prop on <style> tagIf you get this warning it means that your styles were not compiled by styled-jsx.
Please take a look at your setup and make sure that everything is correct and that the styled-jsx transformation is ran by Babel.
No, this feature is not supported. However we support React Fragments, which are available in React 16.2.0
and above.
const StyledImage = ({ src, alt = '' }) => (
<React.Fragment>
<img src={src} alt={alt} />
<style jsx>{`
img {
max-width: 100%;
}
`}</style>
</React.Fragment>
)
When the component accepts a className
(or ad-hoc) prop as a way to allow customizations then you can use the resolve
tag from styled-jsx/css
.
When the component doesn't accept any className
or doesn't expose any API to customize the component, then your only option is to use :global()
styles:
export default () => (
<div>
<ExternalComponent />
<style jsx>{`
/* "div" will be prefixed, but ".nested-element" won't */
div > :global(.nested-element) {
color: red;
}
`}</style>
</div>
)
Please keep in mind that :global()
styles will affect the entire subtree, so in many cases you may want to be careful and use the children (direct descendant) selector >
.
There's an article explaining how to bundle React components with Rollup and styled-jsx as an external dependency.
When working with template literals a common drawback is missing syntax highlighting. The following editors currently have support for highlighting CSS inside <style jsx>
elements.
If you have a solution for an editor not on the list please open a PR and let us now.
The language-babel
package for the Atom editor has an option to extend the grammar for JavaScript tagged template literals.
After installing the package add the code below to the appropriate settings entry. In a few moments you should be blessed with proper CSS syntax highlighting. (source)
"(?<=<style jsx>{)|(?<=<style jsx global>{)|(?<=css)":source.css.styled
The IDE let you inject any language in place with Inject language or reference in an Intention Actions (default alt+enter). Simply perform the action in the string template and select CSS. You get full CSS highlighting and autocompletion and it will last until you close the IDE.
Additionally you can use language injection comments to enable all the IDE language features indefinitely using the language comment style:
import { colors, spacing } from '../theme'
import { invertColor } from '../theme/utils'
const Button = ({ children }) => (
<button>
{children}
{/*language=CSS*/}
<style jsx>{`
button {
padding: ${spacing.medium};
background: ${colors.primary};
color: ${invertColor(colors.primary)};
}
`}</style>
</button>
)
If you're using Emmet you can add the following snippet to ~/emmet/snippets-styledjsx.json
This will allow you to expand style-jsx
to a styled-jsx block.
{
"html": {
"snippets": {
"style-jsx": "<style jsx>{`\n\t$1\n`}</style>"
}
}
}
Launch VS Code Quick Open (⌘+P), paste the following command, and press enter.
ext install Divlo.vscode-styled-jsx-syntax
If you use Stylus instead of plain CSS, install vscode-styled-jsx-stylus or paste the command below.
ext install vscode-styled-jsx-stylus
Launch VS Code Quick Open (⌘+P), paste the following command, and press enter.
ext install Divlo.vscode-styled-jsx-languageserver
Install vim-styled-jsx with your plugin manager of choice.
If you're using eslint-plugin-import
, the css
import will generate errors, being that it's a "magic" import (not listed in package.json). To avoid these, simply add the following line to your eslint configuration:
"settings": {"import/core-modules": ["styled-jsx/css"] }
If you're using TypeScript, then in order to allow <style jsx>
tags to be properly understood by it, create a file named "styled-jsx.d.ts" anywhere within your project containing the following, or add this line to the top of any single existing .ts file within your project:
/// <reference types="styled-jsx" />
If you're using babel to transform styled-jsx code with TypeScript, you need to specify
"jsx": "preserve"
in your tsconfig.json to keep the original JSX and let babel parse and transform with styled-jsx babel plugin.
murmurhash2
(minimal and fast hashing) and an efficient style injection logic.FAQs
Full CSS support for JSX without compromises
We found that styled-jsx demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 3 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Research
Security News
Socket’s threat research team has detected six malicious npm packages typosquatting popular libraries to insert SSH backdoors.
Security News
MITRE's 2024 CWE Top 25 highlights critical software vulnerabilities like XSS, SQL Injection, and CSRF, reflecting shifts due to a refined ranking methodology.
Security News
In this segment of the Risky Business podcast, Feross Aboukhadijeh and Patrick Gray discuss the challenges of tracking malware discovered in open source softare.