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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
classNamedid 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.
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
Add to 'scripts': "dev": "next",
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
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.
256
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
28
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/
20
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