I am using react and axios for frontend, and nextjs with prisma for backend. I have in the database 4000 exercices that contain fitness exercices. I want to create a function where by each key stroke, the api will look for the relevant exercice. I finished creating it, but i have some issues:
The main problem is that the response is delayed from the first keystrokes, because the payload response is tooo large. I created a scrollable UL element to render the elements, because I want to get also the Gif images. So the elements, if the API will find those, will be rendered on the screen.
If I add to each element an on click event, to select the exercice's Id, I get an error "too many re-rendering on the screen".
How can I optimise the function, and how can I solve the error of too many re-render on the screen? Nextjs tells me that it will create an infinite loop....
The frontend looks like this:
const [open, setOpen] = useState(false);
const [keyWord, setKeyWord] = useState('');
const [array, setArray] = useState([]);
const [exerciceId, setExerciceId] = useState('');
// Add exercice
const hadnleAddExercie = async event => {
event.preventDefault();
console.log('exercice added');
}
// Look for exercices
const searchExercices = async event => {
event.preventDefault();
setKeyWord(event.target.value);
const arrayExercices = await getExercicesByKeyWords(keyWord);
setArray(arrayExercices);
console.log(arrayExercices);
}
<div className='flex mt-3 flex-col'>
<input onChange={searchExercices} required placeholder='Search by word...' className='border border-slate-400 p-1 rounded-md flex-1 max-w-sm my-2'/>
<ul className='border border-slate-400 p-1 rounded-md max-w-sm my-2 max-h-52 overflow-scroll'>
{
array.length > 1 && array.map(exercice => (
<li key={exercice.id} className='flex flex-wrap p-2 bg-slate-200 m-2 items-center rounded-md'>
<span><Image className='rounded-xl mr-2' priority width={40} height={40} src={exercice.gifUrl} alt={exercice.name}/></span>
<span>{ exercice.name }</span>
</li>
))
}
</ul>
</div>
The backend Uses prisma and I use the OR clause to look for a word in different rows:
export default async function handler(req, res) {
try {
const param = req.query.slug[0];
console.log(param);
// Get exercices where the two rows contains a single parametter
const exercices = await prisma.exercices.findMany({
where: {
OR: [
{
name: {
contains: param
}
},
{
target: {
contains: param
}
},
{
equipment: {
contains: param
}
}
]
}
});
res.status(200).send(exercices);
}
catch (error) {
console.log(error);
res.status(500).send(error);
}
}
An example can be this:
Only for finding an exercice I used 500mb...
Here are a few ways I can think of to optimize this:
Use pagination and fetch more results as user scrolls down or actually separate it by using pages. You can read more on how to implement pagination in Prisma here.
Add debounce to your search term so it doesn't actually fire on every single keystroke, you could use something like useDebounce.
Use React.memo to prevent the list from being re-rendered every time some state changes, only re-render it when the actual list changes.
I want to test a stencil component and configure a global variable in my test like this:
describe('my-component', () => {
const myVarMock = 1;
let page;
let shadowRoot: ShadowRoot;
beforeEach(async () => {
page = await newSpecPage({
components: [MyComponent],
html: `<my-component></my-component>`,
supportsShadowDom: true,
autoApplyChanges: true
});
shadowRoot = page.root.shadowRoot;
});
it('should test', () => {
page.rootInstance.myVar= myVarMock;
page.rootInstance.componentWillLoad();
page.rootInstance.render();
console.log(shadowRoot.innerHTML.toString());
const buttonElement = shadowRoot.querySelector('.my-button'); //is null because shadow root is empty
});
});
My Component only renders something, when myVar is set. In the console.log of my test, shadowRoot is always empty, although I explicitly call render() in the test and when I go through the render function in debug-mode it has a value for myVar and renders everything. But why is shadowRoot then empty and my buttonElement is undefined?
Component:
#Component({
tag: 'my-component',
shadow: true,
})
export class MyComponent{
public myVar;
componentWillLoad() {
...
}
render() {
return (
<Host>
{this.myVar? (
<div class="my-button"></div>
): null}
</Host>
)
}
}
Calling those life-cycle hooks like componentWillLoad and render manually does not do what I think you're expecting it to do. The Stencil runtime calls render and uses the return value (JSX) to eventually render your component. Manually calling render does not render or re-render your component. In fact, it doesn't do anything except returning some JSX to you but you're not doing anything with the return value.
I think the main issue in your case is that myVar is not declared as a property with the #Prop() decorator. So even though you have marked your class member as public and are able to change it from the outside, Stencil will not wire up anything for you regarding that prop. See https://stenciljs.com/docs/properties.
Instead, you'll have to define it as:
#Prop() myVar?: number;
That way it will cause Stencil to re-render your component every time you update the prop's value.
Your test case should just look like
it('should test', () => {
page.root.myVar = myVarMock;
console.log(shadowRoot.innerHTML.toString());
const buttonElement = shadowRoot.querySelector('.my-button');
expect(buttonElement).not.toBeNull();
});
I'm having difficulty with differences between client-side and server-side rendering of styles in Material-UI components due to classNames being assigned differently.
The classNames are assigned correctly on first loading the page, but after refreshing the page, the classNames no longer match so the component loses its styling. This is the error message I am receiving on the Console:
Warning: Prop className did not match.
Server: "MuiFormControl-root-3 MuiFormControl-marginNormal-4
SearchBar-textField-31"
Client: "MuiFormControl-root-3 MuiFormControl-marginNormal-4
SearchBar-textField-2"
I've followed the Material-UI TextField example docs, and their accompanying Code Sandbox example, but I can't seem to figure out what is causing the difference between the server and client classNames.
I experienced a similar issue when adding Material-UI Chips with a delete 'x' icon. The 'x' icon rendered with a monstrous 1024px width after refreshing. The same underlying issue being that icon was not receiving the correct class for styling.
There are a few questions on Stack Overflow addressing why the client and server might render classNames differently (e.g. need to upgrade to #Material-UI/core version ^1.0.0, using a custom server.js, and using Math.random in setState), but none of these apply in my case.
I don't know enough to tell whether this Github discussion might help, but likely not since they were using a beta version of Material-UI.
Minimal steps to reproduce:
Create project folder and start Node server:
mkdir app
cd app
npm init -y
npm install react react-dom next #material-ui/core
npm run dev
edit package.json:
Add to 'scripts': "dev": "next",
app/pages/index.jsx:
import Head from "next/head"
import CssBaseline from "#material-ui/core/CssBaseline"
import SearchBar from "../components/SearchBar"
const Index = () => (
<React.Fragment>
<Head>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/css?family=Roboto:300,400,500"
/>
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta charSet="utf-8" />
</Head>
<CssBaseline />
<SearchBar />
</React.Fragment>
)
export default Index
app/components/SearchBar.jsx:
import PropTypes from "prop-types"
import { withStyles } from "#material-ui/core/styles"
import TextField from "#material-ui/core/TextField"
const styles = (theme) => ({
container: {
display: "flex",
flexWrap: "wrap",
},
textField: {
margin: theme.spacing.unit / 2,
width: 200,
border: "2px solid red",
},
})
class SearchBar extends React.Component {
constructor(props) {
super(props)
this.state = { value: "" }
this.handleChange = this.handleChange.bind(this)
this.handleSubmit = this.handleSubmit.bind(this)
}
handleChange(event) {
this.setState({ value: event.target.value })
}
handleSubmit(event) {
event.preventDefault()
}
render() {
const { classes } = this.props
return (
<form
className={classes.container}
noValidate
autoComplete="off"
onSubmit={this.handleSubmit}
>
<TextField
id="search"
label="Search"
type="search"
placeholder="Search..."
className={classes.textField}
value={this.state.value}
onChange={this.handleChange}
margin="normal"
/>
</form>
)
}
}
SearchBar.propTypes = {
classes: PropTypes.object.isRequired,
}
export default withStyles(styles)(SearchBar)
Visit page in browser localhost:3000 and see this:
red border around TextField component
Refresh the browser and see this:
TextField component's styles are gone
Notice that the red border around TextField disappears.
Relevant Libs:
"react": 16.4.0
"react-dom": 16.4.0
"next": 6.0.3
"#material-ui/core": 1.2.0
The problem is the SSR rendering in Next.js, which produces the style fragment before the page is rendered.
Using Material UI and Next.js (as the author is using), adding a file called _document.js solved the problem.
Adjusted _document.js (as suggested here):
import React from 'react';
import Document, { Html, Head, Main, NextScript } from 'next/document';
import { ServerStyleSheets } from '#material-ui/styles'; // works with #material-ui/core/styles, if you prefer to use it.
import theme from '../src/theme'; // Adjust here as well
export default class MyDocument extends Document {
render() {
return (
<Html lang="en">
<Head>
{/* Not exactly required, but this is the PWA primary color */}
<meta name="theme-color" content={theme.palette.primary.main} />
</Head>
<body>
<Main />
<NextScript />
</body>
</Html>
);
}
}
// `getInitialProps` belongs to `_document` (instead of `_app`),
// it's compatible with server-side generation (SSG).
MyDocument.getInitialProps = async (ctx) => {
// Resolution order
//
// On the server:
// 1. app.getInitialProps
// 2. page.getInitialProps
// 3. document.getInitialProps
// 4. app.render
// 5. page.render
// 6. document.render
//
// On the server with error:
// 1. document.getInitialProps
// 2. app.render
// 3. page.render
// 4. document.render
//
// On the client
// 1. app.getInitialProps
// 2. page.getInitialProps
// 3. app.render
// 4. page.render
// Render app and page and get the context of the page with collected side effects.
const sheets = new ServerStyleSheets();
const originalRenderPage = ctx.renderPage;
ctx.renderPage = () =>
originalRenderPage({
enhanceApp: (App) => (props) => sheets.collect(<App {...props} />),
});
const initialProps = await Document.getInitialProps(ctx);
return {
...initialProps,
// Styles fragment is rendered after the app and page rendering finish.
styles: [...React.Children.toArray(initialProps.styles), sheets.getStyleElement()],
};
};
This problem is related to MUI using dynamic class name which contain an ID. The IDs from the server side rendered CSS are not the same as the client side CSS, hence the mismatch error. A good start is to read the MUI SSR documentation
If you have this problem with nextjs (as I did) follow the example provided by the MUI team, which can be found here: material-ui/examples/nextjs
The most important part is in "examples/nextjs/pages/_app.js":
componentDidMount() {
// Remove the server-side injected CSS.
const jssStyles = document.querySelector('#jss-server-side');
if (jssStyles) {
jssStyles.parentElement.removeChild(jssStyles);
}
}
the related ticket can be found here: mui-org/material-ui/issues/15073
what it does, is remove the server side rendered stylesheet and replace it by a new client side rendered one
The issue is the server side generates the class names but style sheets are not automatically included in the HTML. You need to explicitly extract the CSS and append it to the UI for the server side rendered components. The whole process is explained here: https://material-ui.com/guides/server-rendering/
There is one other important, separate issue here: Material UI V4 is not React Strict Mode compatible. Strict mode compatibility is slated for version 5 with the adoption of the Emotion style engine.
Until then, be sure you disable React Strict Mode. If you're using Next.js, this is turned on by default if you've created your app using create-next-app.
// next.config.js
module.exports = {
reactStrictMode: false, // or remove this line completely
}
I had the same problem with Next.js and styled component, with the transpilation by Babel. Actually, the class names are different on the client and the server side.
Fix it in writing this in your .babelrc :
{
"presets": ["next/babel"],
"plugins": [
[
"styled-components",
{ "ssr": true, "displayName": true, "preprocess": false }
]
]
}
I met this problem on Material-ui V5. The solution to fix this problem is to make sure that class name generator needs to behave identically on the server and on the client.
so adding the code below in your _app.js:
import { StylesProvider, createGenerateClassName } from '#mui/styles';
const generateClassName = createGenerateClassName({
productionPrefix: 'c',
});
export default function MyApp(props) {
return <StylesProvider generateClassName={generateClassName}>...</StylesProvider>;
}
// 1 . Warning: prop classname did not match. Material ui with React Next.js
// 2 . Use your customization css here
const useStyles = makeStyles((theme) => ({
root: {
flexGrow: 1,
},
title: {
flexGrow: 1,
},
my_examle_classssss: {
with: "100%"
}
}));
// 3 . Here my Component
const My_Example_Function = () => {
const classes = useStyles();
return (
<div className={classes.root}>
<Container>
<Examle_Component> {/* !!! Examle_Component --> MuiExamle_Component*/}
</Examle_Component>
</Container>
</div>
);
}
export default My_Example_Function
// 4. Add name parameter to the makeStyles function
const useStyles = makeStyles((theme) => ({
root: {
flexGrow: 1,
},
title: {
flexGrow: 1,
},
my_examle_classssss: {
with: "100%"
},
}), { name: "MuiExamle_ComponentiAppBar" });
{/* this is the parameter you need to add { name: "MuiExamle_ComponentiAppBar" } */ }
{/* The problem will probably be resolved if the name parameter matches the first className in the Warning: you recive..
EXAMPLE :
Warning: Prop `className` did not match.
Server: "MuiSvgIcon-root makeStyles-root-98"
Client: "MuiSvgIcon-root makeStyles-root-1"
The name parameter will be like this { name: "MuiSvgIcon" }
*/ }
I like to share this mismatching case:
next-dev.js?3515:32 Warning: Prop className did not match. Server:
"MuiButtonBase-root MuiIconButton-root PrivateSwitchBase-root-12
MuiSwitch-switchBase MuiSwitch-colorSecondary" Client:
"MuiButtonBase-root MuiIconButton-root PrivateSwitchBase-root-12
MuiSwitch-switchBase MuiSwitch-colorSecondary
PrivateSwitchBase-checked-13 Mui-checked"
On client there are two more classes which means that the behavior on client-side is different. In this case, this component shouldn't render on server-side. The solution is to dynamically render this component:
export default dynamic(() => Promise.resolve(TheComponent), { ssr: false });
I had a problem with different classNames for client and server. I was using React, Material-UI, makeStyles and SSR (server-side rendering).
The error was:
Warning: Prop `className` did not match. Server: "jss3" Client: "App-colNav-3"
I spent several hours before I figured out that I had discrepancy in webpack mode for client and server. The scripts in package.json were:
"devServer": "webpack --config webpack.server.config.js --mode=production --watch",
"devClient": "webpack --mode=development --watch",
After I changed both to have development mode, the problem was solved :)
"devServer": "webpack --config webpack.server.config.js --mode=development --watch",
"devClient": "webpack --mode=development --watch",
If somebody is still struggling even after trying above solutions, Try this
If you have used noSsr prop in any of your components or theme, then remove it.
I had the following config in mui theme object, which was causing this problem.
import { createTheme, responsiveFontSizes } from "#mui/material/styles";
let theme = createTheme({
components: {
MuiUseMediaQuery: {
defaultProps: {
noSsr: true,
},
},
},
palette: {
mode: "light",
common: {
black: "#000",
white: "#fff",
},
primary: {
main: "#131921",
contrastText: "#fff",
},
secondary: {
main: "#fb6a02",
contrastText: "#fff",
}
}
})
RemovingnoSSr fixed all of the issues in my app including style mismatch between client and server.
The problem is cause by Nextjs server side rendering. In order to solve I do as following:
Make a component to detect whether is it from Client side
import { useState, useEffect } from "react";
interface ClientOnlyProps {}
// #ts-ignore
const ClientOnly = ({ children }) => {
const [mounted, setMounted] = useState<boolean>(false);
useEffect(() => {
setMounted(true);
}, []);
return mounted ? children : null;
};
export default ClientOnly;
Wrap my page component using ClientOnly component
export default function App() {
return (
<ClientOnly>
<MyOwnPageComponent>
</ClientOnly>
);
}
So the idea is, if it is client side then only render the component on the page. Therefore if current rendering is from Client side, render <MyOwnPageComponent>, else render nothing
In my case the issue happened because of different compilation modes of webpack for client-side code and server-side: client's bundle was generated by webpack using "production" mode, while server ran some SSR code from a package optimized for "development". This created a different "className" hash in styled-components in generateAndInjectStyles():
if (process.env.NODE_ENV !== 'production') dynamicHash = phash(dynamicHash, partRule + i);
So my fix was just to align the webpack modes.
You can add the name in anywhere you use makeStyles, like this:
const useStyles = makeStyles({
card: {
backgroundColor: "#f7f7f7",
width: "33%",
},
title: {
color: "#0ab5db",
fontWeight: "bold",
},
description: {
fontSize: "1em"
}
}, { name: "MuiExample_Component" });
I am not sure how it works, but I found it here: Warning: Prop `className` did not match ~ Material UI css arbitrarily breaks on reload
I'm also using NextJS + MUI v5 and I ran into this exact error right after merging Git branches. I suspect the merge corrupted something in the cache. I deleted the contents of .next/ and restarted the dev server and the error went away.
#Leonel Sanches da Silva's answer didn't work for me, as #material-ui/styles is deprecated, but using a snippet I found for another (non-material UI) project seems to have worked just fine for me:
Hat tip to Raul Sanchez on dev.to for the answer to this one.
Next doesn't fetch styled-components styles on the server, to do that you need to add this page to pages/_document.js:
import Document from 'next/document'
import { ServerStyleSheet } from 'styled-components'
export default class MyDocument extends Document {
static async getInitialProps(ctx) {
const sheet = new ServerStyleSheet()
const originalRenderPage = ctx.renderPage
try {
ctx.renderPage = () =>
originalRenderPage({
enhanceApp: (App) => (props) =>
sheet.collectStyles(<App {...props} />),
})
const initialProps = await Document.getInitialProps(ctx)
return {
...initialProps,
styles: (
<>
{initialProps.styles}
{sheet.getStyleElement()}
</>
),
}
} finally {
sheet.seal()
}
}
}
This code may update, so check Next's styled-components example for the latest.
I used to compile and insert JSX components via
<div key={ ID } dangerouslySetInnerHTML={ { __html: HTML } } />
which wrapped my HTML into a <div>:
<div>my html from the HTML object</div>
Now react > 16.2.0 has support for Fragments and I wonder if I can use that somehow to avoid wrapping my HTML in a <div> each time I get data from the back end.
Running
<Fragment key={ ID } dangerouslySetInnerHTML={ { __html: HTML } } />
will throw a warning
Warning: Invalid prop `dangerouslySetInnerHTML` supplied to `React.Fragment`. React.Fragment can only have `key` and `children` props.
in React.Fragment
Is this supported yet at all? Is there another way to solve this?
Update
Created an issue in the react repo for it if you want to upvote it.
Short Answer
Not possible:
key is the only attribute that can be passed to Fragment. In the
future, we may add support for additional attributes, such as event
handlers.
https://reactjs.org/docs/fragments.html
You may want to chime in and suggest this as a future addition.
https://github.com/facebook/react/issues
In the Meantime
You may want to consider using an HTML parsing library like:
https://github.com/remarkablemark/html-react-parser
Check out this example to see how it will accomplish your goal:
http://remarkablemark.org/blog/2016/10/07/dangerously-set-innerhtml-alternative/
In Short
You'll be able to do this:
<>
{require('html-react-parser')(
'<em>foo</em>'
)}
</>
Update December 2020
This issue (also mentioned by OP) was closed on Oct 2, 2019. - However, stemming from the original issue, it seems a RawHTML component has entered the RFC process but has not reached production, and has no set timeline for when a working solution may be available.
That being said, I would now like to allude to a solution I currently use to get around this issue.
In my case, dangerouslySetInnerHTML was utilized to render plain HTML for a user to download; it was not ideal to have additional wrapper tags included in the output.
After reading around the web and StackOverflow, it seemed most solutions mentioned using an external library like html-react-parser.
For this use-case, html-react-parser would not suffice because it converts HTML strings to React element(s). Meaning, it would strip all HTML that wasn't standard JSX.
Solution:
The code below is the no library solution I opted to use:
//HTML that will be set using dangerouslySetInnerHTML
const html = `<div>This is a div</div>`
The wrapper div within the RawHtml component is purposely named "unwanteddiv".
//Component that will return our dangerouslySetInnerHTML
//Note that we are using "unwanteddiv" as a wrapper
const RawHtml = () => {
return (
<unwanteddiv key={[]}
dangerouslySetInnerHTML={{
__html: html,
}}
/>
);
};
For the purpose of this example, we will use renderToStaticMarkup.
const staticHtml = ReactDomServer.renderToStaticMarkup(
<RawHtml/>
);
The ParseStaticHtml function is where the magic happens, here you will see why we named the wrapper div "unwanteddiv".
//The ParseStaticHtml function will check the staticHtml
//If the staticHtml type is 'string'
//We will remove "<unwanteddiv/>" leaving us with only the desired output
const ParseStaticHtml = (html) => {
if (typeof html === 'string') {
return html.replace(/<unwanteddiv>/g, '').replace(/<\/unwanteddiv>/g, '');
} else {
return html;
}
};
Now, if we pass the staticHtml through the ParseStaticHtml function you will see the desired output without the additional wrapper div:
console.log(ParseStaticHtml(staticHtml));
Additionally, I have created a codesandbox example that shows this in action.
Notice, the console log will throw a warning: "The tag <unwanteddiv> is unrecognized in this browser..." - However, this is fine because we intentionally gave it a unique name so we can easily differentiate and target the wrapper with our replace method and essentially remove it before output.
Besides, receiving a mild scolding from a code linter is not as bad as adding more dependencies for something that should be more simply implemented.
i found a workaround
by using react's ref
import React, { FC, useEffect, useRef } from 'react'
interface RawHtmlProps {
html: string
}
const RawHtml: FC<RawHtmlProps> = ({ html }) => {
const ref = useRef<HTMLDivElement>(null)
useEffect(() => {
if (!ref.current) return
// make a js fragment element
const fragment = document.createDocumentFragment()
// move every child from our div to new fragment
while (ref.current.childNodes[0]) {
fragment.appendChild(ref.current.childNodes[0])
}
// and after all replace the div with fragment
ref.current.replaceWith(fragment)
}, [ref])
return <div ref={ref} dangerouslySetInnerHTML={{ __html: html }}></div>
}
export { RawHtml }
Here's a solution that works for <td> elements only:
type DangerousHtml = {__html:string}
function isHtml(x: any): x is DangerousHtml {
if(!x) return false;
if(typeof x !== 'object') return false;
const keys = Object.keys(x)
if(keys.length !== 1) return false;
return keys[0] === '__html'
}
const DangerousTD = forwardRef<HTMLTableCellElement,Override<React.ComponentPropsWithoutRef<'td'>,{children: ReactNode|DangerousHtml}>>(({children,...props}, ref) => {
if(isHtml(children)) {
return <td dangerouslySetInnerHTML={children} {...props} ref={ref}/>
}
return <td {...props} ref={ref}>{children}</td>
})
With a bit of work you can make this more generic, but that should give the general idea.
Usage:
<DangerousTD>{{__html: "<span>foo</span>"}}</DangerousTD>