Using Emotion for a React project I'm styling a particular div element with padding-bottom as the following:
export const StyledItem = styled('div')(() => ({
'&:nth-child(1) > div:nth-child(1)': {
paddingBottom: '1px'
}
}))
And getting the following error message in Chrome's console:
The pseudo class ":nth-child" is potentially unsafe when doing server-side rendering. Try changing it to ":nth-of-type".
See the screenshot from the console:
The following change resolves the issue and removes the error message from the console:
export const StyledItem = styled('div')(() => ({
'&:nth-of-type(1) > div:nth-of-type(1)': {
paddingBottom: '1px'
}
}))
See the dependencies from package.json:
"dependencies": {
"#emotion/core": "^10.0.28",
"#emotion/styled": "^10.0.27",
"react": "^16.13.1",
"#storybook/react": "^5.3.13",
/* other dependencies */
}
Question:
So the suggested change for the error message resolved the issue. Also checked this question and this GitHub issue already which are not giving me a clear explanation.
The question is why is that error message has shown if the things are happening on client side and not on server side as the message states? Thank you!
When SSR renders the components, it also renders style elements along with it. The first child of the component may be a style element and using n-th-child could potentially be unsafe as it would be unintended behaviour.
EmotionJS GitHub Issue
Related
I'm trying to use Next.js next/future/image experimental component.
I upgraded the Next.js version in package.json to "next": "^12.2.0".
Here's my next.config.js file:
/** #type {import('next').NextConfig} */
const nextConfig = {
strictMode: true,
experimental: {
images: {
allowFutureImage: true,
},
},
images: {
domains: ['firebasestorage.googleapis.com',],
},
};
module.exports = nextConfig;
It doesn't allow me to use this feature. Here's the error message in the browser console:
Error: The "next/future/image" component is experimental and may be subject to breaking changes. To enable this experiment, please include `experimental: { images: { allowFutureImage: true } }` in your next.config.js file.
For Next v13 users:
I believe next/future/image is now the default Image component. So no additional work necessary! Just import and use
import Image from 'next/image'
For Next v12.3 users(like the author of this question)
You don't need to add anything to the config to use future/image. The future image is now stable. Just use it directly by importing
import Image from 'next/future/image'
In fact, adding an images property to the config will cause an error, since the config schema has been updated. So don't do that.
// next.config.js
module.exports = {
experimental: {
images: { // This will cause an error
allowFutureImage: true,
},
},
}
The solution that worked for me was to add the experimental rule and stop the nextjs server and restart it. Then it would start working
module.exports = {
experimental: {
images: {
allowFutureImage: true,
},
},
}
I'm currently working with NextJS version 12.3.1, and if I enable it in the next.config.js then I get an ugly warning on the terminal. So it is best to just import Image from "next/future/image" and not add the config to avoid the Warning. Hope others using 12.3.1 find this useful ( using future/image gets rid of the nasty wrapper divs/spans around the )
Warning I'm seeing with config in place:
ready - started server on 0.0.0.0:3000, url: http://localhost:3000
warn - Invalid next.config.js options detected:
- The value at .experimental has an unexpected property, images, which is not in the list of allowed properties (adjustFontFallbacks, amp, appDir, browsersListForSwc, cpus, craCompat, disableOptimizedLoading, disablePostcssPresetEnv, esmExternals, externalDir, fallbackNodePolyfills, forceSwcTransforms, fullySpecified, gzipSize, incrementalCacheHandlerPath, isrFlushToDisk, isrMemoryCacheSize, largePageDataBytes, legacyBrowsers, manualClientBasePath, modularizeImports, newNextLinkBehavior, nextScriptWorkers, optimizeCss, optimisticClientCache, outputFileTracingRoot, pageEnv, profiling, proxyTimeout, runtime, scrollRestoration, serverComponents, sharedPool, sri, swcFileReading, swcMinify, swcMinifyDebugOptions, swcPlugins, swcTraceProfiling, urlImports, workerThreads).
See more info here: https://nextjs.org/docs/messages/invalid-next-config
warn - You have enabled experimental feature (images) in next.config.js.
warn - Experimental features are not covered by semver, and may cause unexpected or broken application behavior. Use at your own risk.
I wanted to use Emotion with CRA so I installed it following the documentation and tried to use the css prop as shown in the example below :
import { FC } from "react";
import { TypographyProps } from "./Typography.propTypes";
import * as styles from "./Typography.styles";
export const Typography: FC<TypographyProps> = ({
children,
}) => {
return <h1 css={styles.typography}>{children}</h1>;
};
but it didn't work.
By inspecting the code, I found this :
<h1 css="You have tried to stringify object returned from `css` function.
It isn't supposed to be used directly (e.g. as value of the `className` prop),
but rather handed to emotion so it can handle it (e.g. as value of `css` prop).">
Header</h1>
I tried following the solution from this blog article, but still didn't work :
https://harryhedger.medium.com/quick-how-to-use-the-emotion-css-prop-with-create-react-app-5f6aa0f0c5c5
Any thing I can do to fix it?
Thanks!
The easiest way to fix this is to add the following line at the beginning of your file.
/** #jsxImportSource #emotion/react */
I use material UI (verison: ^4.12.3) Select, with custom input.
For some reason the prod env Select input has a black background and :before element with white background.
I don't know from where it comes from.
this is image of the prod:
this is image of the dev Select:
when comparing the 2 css & html of the envs Select element, it's is shown that there is a ::before element added in prod that is not presented in dev
also, the background color is different. in prod there is another class added to the InputBase element, which doesn't exist in dev. this class adds a background-color black:
Edit 1
it seems like MUI inject <style>. in the prod html i see the background-color: black and the ::before. ill try adding the index solution, but my problem is not precedence (the style that i do use override the injected style). also, it wont help the ::before element. how to disable the injected styles ? or work around it ?
the injected bad css:
Please refer to this question. As answered by user Mordechai.
It seems like webpack could mess with MUI's rules on JSS precedence... This could be solved by adding an index of one to MUI's methods.
//Hook
const useStyles = makeStyles({
// your styles here
}, {index: 1})
// HOC
MyComponent = withStyles({
// your styles here
}, {index: 1})(MyComponent)
adding <StylesProvider /> wrapper to the app fixed it. we use micro-frontend infrastructure. and one of the frontends app also had makeStyles. this is causing classNames conflicts in MUI.
in the root component <App/>:
import {
StylesProvider,
createGenerateClassName
} from '#material-ui/core/styles';
const generateClassName = createGenerateClassName({
seed: 'app1'
});
const App = () => {
return (
<StylesProvider generateClassName={generateClassName}>
<OtherAppComponents />
</StylesProvider>
)
}
if you have more then 2 add a provider and a generator to each, with different seed
I want to display Flags icons inside a React Bootstrap selection Option. I have tried both CSS based and React based libraries to do so and in each case I get only [object object]
I have tried with the https://github.com/lipis/flag-icon-css CSS library
<Form.Control as="select">
<option><span className="flag-icon flag-icon-gr"></span></option>
</Form.Control>
Which gives me a warning and the same [Object object]
Warning: Only strings and numbers are supported as <option> children.
I have also attempted with the React wrapper for the same library https://www.npmjs.com/package/react-flag-icon-css
<Form.Control as="select">
<option><FlagIcon className="countryIcon" code="us" size="lg"/></option>
</Form.Control>
Which does not generate a warning but no results either
Does anyone know how I can get something else than string or number in the Option, or another way to include an icon ?
Option HTML tag accepts text only, it can't accept any other HTML, it will strip it. You can check this React issue [bug][16.5.0] option returns [object Object] instead of string and read the comment by Dan Abramov:
I don't think it was strictly a regression. This is kind of a thorny
area. It was never intentionally supported. It accidentally worked on
initial mount but then crashed on updates (#13261). Fixing the crash
was more important, so we fixed it to be treated as text content
(which it should be). Unfortunately this means putting custom
components in the middle is not supported. That's consistent with how
textarea and similar elements work.
I think it's better to show invalid output and warn about something
that breaks on updates, than to let people use it only to discover it
crashes in production. But I can see arguments for why this should be
supported when the custom component returns a string. Unfortunately I
don't know how to fix it in a way that would both solve the update
crashes and support text-only content. I think for now it's reasonable
to say putting custom components into doesn't really work
(and never quite worked correctly), and ask you to manually provide a
string to it.
Alternatively, you can use Bootstrap Dropdowns to create a dropdown button with a list of countries using the code below:
App.js:
...
import Dropdown from 'react-bootstrap/Dropdown';
import FlagIcon from './FlagIcon.js'
function App() {
const [countries] = useState([
{ code: 'gr', title: 'Greece'},
{ code: 'gb', title: 'United Kingdom'},
{ code: 'us', title: 'United States'}
]);
const [toggleContents, setToggleContents] = useState("Select a country");
const [selectedCountry, setSelectedCountry] = useState();
return (
<div className="App">
<Form>
<Dropdown
onSelect={eventKey => {
const { code, title } = countries.find(({ code }) => eventKey === code);
setSelectedCountry(eventKey);
setToggleContents(<><FlagIcon code={code}/> {title}</>);
}}
>
<Dropdown.Toggle variant="secondary" id="dropdown-flags" className="text-left" style={{ width: 300 }}>
{toggleContents}
</Dropdown.Toggle>
<Dropdown.Menu>
{countries.map(({ code, title }) => (
<Dropdown.Item key={code} eventKey={code}><FlagIcon code={code}/> {title}</Dropdown.Item>
))}
</Dropdown.Menu>
</Dropdown>
</Form>
</div>
);
}
FlagIcon.js:
import React from 'react';
import FlagIconFactory from 'react-flag-icon-css';
// const FlagIcon = FlagIconFactory(React);
// If you are not using css modules, write the following:
const FlagIcon = FlagIconFactory(React, { useCssModules: false })
export default FlagIcon;
You'll get a dropdown button like this:
You can also check this working Stackblitz: https://stackblitz.com/edit/react-bootstrap-flags-dropdown-menu
Are you closing the tag
<Form.Control as="select">
[object Object] is displayed e.g when you are concatenating a string with an object, for example:
console.log(""+{})
I am writing a custom component that I would like to define other component dependencies.
The dependencies are different animations types.
Let's say they have the names "animation__x" and "animation__y"
x and y can be any name, so I am looking for something like animation__*
or /animation__\s*/
The only way I have made this work at the moment is either ensuring my component is placed after the animation components on the HTML or alternatively to force update components using this.el.updateComponents()
Neither of these solutions feels right to me.
AFRAME.registerComponent('cool-component', {
dependencies: ['animation'],
update: functions(data){
//detect available animations and do some stuff with them
let animations = Object.keys(components).filter((key) => {
return /(^animation__\w*)/.test(key);
});
//animations results in an empty array
}
});
html that is not working
<a-scene cool-component animation__x="" animation__y="" animation__z=""></a-scene>
html that is working (but its not good as I cant ensure my component is always last in the list
<a-scene animation__x="" animation__y="" animation__z="" cool-component></a-scene>
js that works, but doesnt feel write as I am using the entities internal functions
AFRAME.registerComponent('cool-component', {
dependencies: ['animation'],
update: functions(data){
this.el.updateComponents(); //<-- I DONT LIKE THIS BUT IT WORKS
//detect available animations and do some stuff with them
//now all animations are available as this.el.components
let animations = Object.keys(components).filter((key) => {
return /(^animation__\w*)/.test(key);
});
}
});
Three options:
Depend on the specific component names: dependencies: ['animation__xxx']
Make cool-component set those animations:
AFRAME.registerComponent('cool-component', {
init: functions(data){
this.el.setAttribute('animation__xxx', {...});
}
});
You can also defer cool-component logic until the entity has loaded and all the components have initialized:
init: function () {
this.el.addEvenListener(‘loaded’, this.doStuffAferComponentsLoad.bind(this));
}
More details in what cool-component is trying to accomplish will help to get a more precise answer.