Any nextjs example where I need to use _document over _app - next.js

It seems I can do everything that I need to do in both _app and _document for my application just in _app like
// _app.tsx
import Head from 'next/head';
export default function App({ Component, pageProps }) {
return (
<>
<Head>
<meta
name="viewport"
content="width=device-width, initial-scale=1, shrink-to-fit=no, user-scalable=no"
/>
<title>Payment</title>
</Head>
<Component {...pageProps} />
</>
);
}
Then when should I use _document necessarily? I found _document pointless because:
I shouldn't place viewport meta tags in _document as nextjs compiler warnings about it. (I thought _document is a good place for markups in head because _document gets called only once on server-side and not on client-side) If I can't place everything of a kind like head markup in one place, I'd like to avoid using that way.

You'll need _document if you want to customize a page's <html> and <body> tags. For example...
Adding the global lang attribute:
<Html lang="en">
Adding custom styles:
<body className="bg-white">

_document is where you put third party links and scripts
import Document, { Html, Head, Main, NextScript } from 'next/document'
class MyDocument extends Document {
render() {
return (
<Html>
<Head>
<link
href="https://fonts.googleapis.com/css2?family=Inter&display=optional"
rel="stylesheet"
/>
</Head>
<body>
<Main />
<NextScript />
</body>
</Html>
)
}
}
export default MyDocument
If you are using styled components you need to configure it in _document.jsx file.
https://github.com/massaaki/nextjs-with-styled-component/blob/main/src/pages/_document.tsx

Related

How to get locale in nextjs in document component?

I want to set locale in script google map like this:
<script defer src={`https://maps.googleapis.com/maps/api/js?key=key&libraries=places&language=${locale}`}/>
but how can i get to locale in Document nextJS?
useRouter doesnot work in Document component.
export default function Document() {
return (
<Html>
<Head>
<link rel="preconnect" href="https://fonts.googleapis.com" />
<script defer src={`https://maps.googleapis.com/maps/api/js?key=key&libraries=places&language=${locale}`}/>
</Head>
<body>
<Main />
<NextScript />
</body>
</Html>
);
}
You can access locale in this.props.locale.
In my project this locale uses in this case:
<Html lang={this.props.locale}>
/....
I use class component in _document.
In your variant you can access locale just in props.
import { Html, Head, Main, NextScript } from "next/document";
export default function Document(props: DocumentProps) {
return (
<Html lang={props.locale}>
<Head />
<body>
<Main />
<NextScript />
</body>
</Html>
);
}
It works if you already add i18n config, and inject it to next config.
https://codesandbox.io/p/sandbox/musing-noether-7loye1?file=%2Fpages%2F_document.tsx&selection=%5B%7B%22endColumn%22%3A9%2C%22endLineNumber%22%3A11%2C%22startColumn%22%3A9%2C%22startLineNumber%22%3A11%7D%5D

Importing a css file for a different page in React

I am having an issue where when I try and import css onto each page, it will appear on all pages instead of just one. I have my CSS importing in _document.js
import { Html, Head, Main, NextScript } from 'next/document'
export default function Document() {
return (
<Html>
<Head>
<link rel="stylesheet" href="/styles/index.css" />
<link rel="stylesheet" href="index.css"/>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.1/css/fontawesome.min.css" integrity="sha512-xX2rYBFJSj86W54Fyv1de80DWBq7zYLn2z0I9bIhQG+rxIF6XVJUpdGnsNHWRa6AvP89vtFupEPDP8eZAtu9qA==" crossOrigin="anonymous" referrerPolicy="no-referrer" />
</Head>
<body>
<Main />
<NextScript />
</body>
</Html>
)
}
and I want to know how I can import this CSS on a per-page basis, instead of having all css files on all pages. I have tried importing the css inside of each JS file, but it seems to want to go to /pagehere/styles/settings.css instead of /styles/settings.css even when I put import '../styles/settings.css'. Thanks.
Remove the <Link>s and try using import '../../stryles/settings.css' instead.

Head component from next/head renders into <body> instead of <head>

I am setting up a project in nextjs. I would like to add some global meta tags and title to the project. I used the Head component from next/head in _app.tsx but they are being rendered in the body instead of the head both on localhost and when deployed using vercel. I have used next before and can't remember running into this issue.
Here is my _app.tsx
import { AppProps } from 'next/app'
import Head from 'next/head'
import Footer from '../components/footer'
import MobileNavBar from '../components/mobileNavBar'
import NavBar from '../components/navBar'
import '../styles.scss'
const App = ({ Component, pageProps }: AppProps) => {
return (
<>
<Head>
<html lang="en" />
<title> Erika's Dog Training </title>
<meta
content="width=device-width, initial-scale=1, maximum-scale=5, shrink-to-fit=no"
name="viewport"
></meta>
<script type="text/javascript" src="https://assets.calendly.com/assets/external/widget.js"></script>
</Head>
<MobileNavBar />
<NavBar />
<Component {...pageProps} />
<Footer />
</>
)
}
export default App;
So the meta tag and title here are showing up on the page, but at the top of the <body> tag instead of in <head>
I had the same problem with next: "11.1.2". Removing <html lang="en" /> fixed the problem. I added the lang value back using: (https://melvingeorge.me/blog/set-html-lang-attribute-in-nextjs)
/* next.config.js */
module.exports = {
i18n: {
locales: ["en"],
defaultLocale: "en",
},
};
Consider the structure of this example from the nextjs documentation.
import Document, { Html, Head, Main, NextScript } from 'next/document'
class MyDocument extends Document {
static async getInitialProps(ctx) {
const initialProps = await Document.getInitialProps(ctx)
return { ...initialProps }
}
render() {
return (
<Html>
<Head />
<body>
<Main />
<NextScript />
</body>
</Html>
)
}
}
export default MyDocument
The main differences that I see, is that in the documentation they place both head and body as siblings within <Html> tags. I suspect that is your problem. I would also remove the empty <> and </> tags.
You have the line: <html lang="en" /> Inside the Head tag. This is going to make it challenging for next to generate the correct html as the html tag is generally above both Head and body tags.
Place <html lang="XX"/> as the last child of <Head>.
Example:
<Head>
<title> Erika's Dog Training</title>
<meta content="width=device-width, initial-scale=1, maximum-scale=5, shrink-to-fit=no" name="viewport" />
<html lang="en" />
</Head>

Set default Head for all pages in NextJS?

Can you set a default value for the Head component in NextJS that other pages will extend from?
In my case I need to load a font on every page:
<Head>
<link
href="path-to-font"
rel="stylesheet"
/>
</Head>
I could do this with a custom document file, but a default value for Head seems simpler.
https://nextjs.org/docs/advanced-features/custom-document
If the Head doesn't require change often, you can take the custom document approach. However if you want things to be dynamic like different title for different pages I would suggest keeping the static layout in custome-document and the dynamic layout separate in another component like
in _document.js
// this will define the default layout for the page
render() {
return (
<Html lang="en">
<Head>
<meta httpEquiv="Content-Type" content="text/html; charset=utf-8" />
<meta
name="viewport"
content="width=device-width, initial-scale=1.0"
/>
// links for static assets
</Head>
<body>
<Main />
<NextScript />
</body>
</Html>
);
}
If you want things to be dynamic like the title, create a new Layout component that wraps all the components is a specific page.
const Layout = ({children, title="default title", description="default-description"}) => {
return (
<>
<Head>
<meta name="description" content={description} />
<title>{title}</title>
</Head>
// you can header component here
<main>
{children}
</main>
// you can add your footer component here
</>
);
}
Now you just need to wrap you page with the Layout for things to be dynamic.
const MyPage = (props) => {
return (
<Layout title="the-dynamic-title" description="the-dynamic-description">
// all other components for your page goes here
</Layout>
)
}

Can you have multiple, additive 'HEAD' elements in NextJS?

I want to be able to have a 'master' HEAD element in _document.js and for certain pages have an additional HEAD element that adds to what is in the 'master'. From https://nextjs.org/docs/api-reference/next/head it would seem that this is possible.
However, when searching for the answer in Stack Overflow, I found this post, which seems to indicate that this can lead to unexpected results.
If I can't have multiple HEAD elements, do I need to pass data from the individual page through getInitialProps?
You can simple import next/head into any page/component when you need to do something with it
Example:
import Head from 'next/head'
function IndexPage() {
return (
<div>
<Head>
<title>My page title</title>
<meta name="viewport" content="initial-scale=1.0, width=device-width" />
</Head>
<p>Hello world!</p>
</div>
)
}
export default IndexPage
and also have a default Head within _document.js
import Document, { Head, Main, NextScript } from 'next/document';
export default class MyDocument extends Document {
render() {
return (
<html lang="en">
<Head>
<link rel="shortcut icon" href="/favicon.ico" />
</Head>
<body>
<Main />
<NextScript />
</body>
</html>
);
}
}
I am not experiencing any issue so far.
Something to remember though:
The contents of head get cleared upon unmounting the component, so make sure each page completely defines what it needs in head, without making assumptions about what other pages added.

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