According to next.js documentation, if you want to customize <App>, you have to create a pages/_app.js page, then put your modifications inside.
Still, in their example there is some code, and I don't know what's its purpose:
import React from 'react'
import App, { Container } from 'next/app'
export default class MyApp extends App {
static async getInitialProps({ Component, router, ctx }) {
let pageProps = {}
if (Component.getInitialProps) {
pageProps = await Component.getInitialProps(ctx)
}
return { pageProps }
}
render () {
const { Component, pageProps } = this.props
return (
<Container>
<Component {...pageProps} />
</Container>
)
}
}
Is this the minimal form? Does this example changes the initial behavior?
In other words, is this code sufficient to extends the original app:
import React from 'react'
import App from 'next/app'
export default class MyApp extends App {}
Yes, what you have there won't change anything and is the minimum to extend App (I've tested this).
I think the reason they've included the overridden getInitialProps and render methods in the documentation is because these are likely the places that you'd want to add customizations to and the code in these is needed if you are overriding them.
For example, if you override getInitialProps but don't return the result of Component.getInitialProps(ctx) (in this case Component is the current page component, like ./pages/index.js) then your page components won't have initial props set.
Related
Suppose my URL looks something like this:
/blog/[post_id]/something
What is the recommended way to pass $post_id down to any component anywhere in the tree?
I know how to retrieve route parameters using getInitialProps but passing the values down is always giving me a hard time.
For pages I could technically use React Contexts although this seems a bit oversized for such a trivial use case.
For layouts I am honestly completely lost because pages are children of layouts and the return value of getInitialProps is passed to the page and not the layout.
My components could make use of useRouter but this requires useEffect and would also make my component depend on the route itself...
Any advice would be welcome (:
My components could make use of useRouter but this requires useEffect and would also make my component depend on the route itself...
useRouter seems like the obvious solution here. I'm not exactly understanding your concerns regarding the component depending on the route. I guess it does make the Layout less flexible since it needs to know that the post id is stored in the post_id query variable. But I would do it anyways :) It gives you a nice and simple way to access the query variables which can be used in a Layout that's outside of your BlogPost or in a deeply-nested component that you use inside the BlogPost.
Using the per-page layouts approach:
/components/Layout
import { useRouter } from "next/router";
import { ReactNode } from "react";
export default function Layout({ children }: { children: ReactNode }) {
const router = useRouter();
return (
<div>
<h3>You are viewing post id #{router.query.post_id}</h3>
{children}
</div>
);
}
/pages/blog/[post_id].jsx
import Layout from '../../components/Layout';
export default function BlogPost() {
return <div>Hello World</div>
}
BlogPost.getLayout = function getLayout(page) {
return (
<Layout>
{page}
</Layout>
)
}
/pages/_app.tsx (to support per-page layouts, copied from docs)
export default function MyApp({ Component, pageProps }) {
// Use the layout defined at the page level, if available
const getLayout = Component.getLayout || ((page) => page)
return getLayout(<Component {...pageProps} />)
}
I think the easiest and the cleanest way is to use window.location.pathname. this will give you the part after the domain name. for example for
http://localhost:3001/blog/[post_id]/something
you will get /blog/[post_id]/something
const pathname=window.location.pathname
const splittedPathname=pathname.split("/") // ['', 'blog', '[post_id]', 'something']
const dynamicId=splittedPathname[2]
you can run above code in useEffect and set a state. or you could write a hook and use it in the components that under dynamicId components
import React, { useState, useEffect } from "react";
const usePathname = () => {
const [postId, setPostId] = useState("");
useEffect(() => {
const pathname = window.location.pathname;
const splittedPathname = pathname.split("/");
const dynamicId = splittedPathname[2];
setPostId(dynamicId);
}, []);
return { postId };
};
export default usePathname;
If you are looking for client side rendering, useRouter is the best way to go. If you are looking for SSR or SSG, you should rather use getStaticProps or getServerSideProps.
I am trying to create a simple page which two main parts: Menu and Guide. In my App,tsx, I have:
import React from 'react';
import Guide from './Guide/Guide';
import './App.css';
function App() {
return (
<Guide />
);
}
export default App;
This is fine.
But, in the ./Guide/Guide.tsx, I have:
import React, { Component } from "react";
import Menu from "./Menu/Menu";
export default class Guide extends Component {
constructor(props: {}) {
super(props);
}
return (
<Menu />
);
}
Menu.tsx:
import React, { Component } from "react";
export default class Menu extends Component {
return (
<h1>Test</h1>
);
};
However I'm getting the error 'return', which lacks return-type annotation, implicitly has an 'any' return type..
What's going on here?
You can probably tell I'm very new to React and TypeScript!
In class component (such as your Guide and Menu components), you render some HTML code inside the render function. Insinde functional components (such as your App component), you render some HTML code inside the return function. Here you are mixing those 2 different syntax, that is why you are getting this error.
In order to fix this, simply replace your return function in the Menu and Guide components by the render function
I'm going through this article and I'm trying to figure out how the persistence is supposed to occur in Option 4. From what I can tell, you'd need to redefine the .getLayout for every page. I'm not sure how the logic for nesting is incorporated into further urls.
Here's the code from the article
// /pages/account-settings/basic-information.js
import SiteLayout from '../../components/SiteLayout'
import AccountSettingsLayout from '../../components/AccountSettingsLayout'
const AccountSettingsBasicInformation = () => <div>{/* ... */}</div>
AccountSettingsBasicInformation.getLayout = page => (
<SiteLayout>
<AccountSettingsLayout>{page}</AccountSettingsLayout>
</SiteLayout>
)
export default AccountSettingsBasicInformation
// /pages/_app.js
import React from 'react'
import App from 'next/app'
class MyApp extends App {
render() {
const { Component, pageProps, router } = this.props
const getLayout = Component.getLayout || (page => page)
return getLayout(<Component {...pageProps}></Component>)
}
}
export default MyApp
For example, say AccountSettingsBasicInformation.getLayout is /settings/, how would I use this template to produce something at /settings/username
P.S. If someone has done something in the past they'd recommend over this, I'm open to ideas.
Yes, you have to redefine the getLayout function to every page. As long as the SiteLayout component stays “unchanged” (eg.no props change) the rendered content in that layout component (not the page content itself) stays persistent. This is because React wont rerender that component.
I used Adam’s article when I was building next.js lib for handlin modal routes. You can check the example folder where you can see I am defining the getLayout property on every page which should be rendered with layout.
Example: https://github.com/svobik7/next-bodies/tree/master/example
I have a website built in React Js and the same one on Next Js as well.
The problem which I am facing right now is, the router seems very slow in the nextJs compare to react-router-dom, It's taking almost 2-3 seconds to change the route.
Here are the URLs where you can feel the difference between the performance by moving around different pages.
https://cutt.ly/mhbPkOE (React Router Dom) vs
https://cutt.ly/BhbPvHv (NextJs)
I had read some comments on Github where few experts are saying that It will resolve in production. but It looks same in production too.
Please have a look at the following code
_app.jsx
// import App from 'next/app'
import React from "react"
import Router from 'next/router';
import "../static/sass/application.scss";
import "bootstrap/dist/css/bootstrap.min.css";
import "slick-carousel/slick/slick.css";
import "slick-carousel/slick/slick-theme.css";
import 'semantic-ui-css/semantic.min.css'
import { wrapper } from "../../redux/utils/store"
import App from 'next/app';
// A simple component that we created
import {LoaderOverlay} from '../components/Reusable'
class MyApp extends App {
constructor(props){
super(props)
this.state = {
isLoading: false,
}
Router.onRouteChangeStart = (url) => {
// Some page has started loading
this.setState({
isLoading: true,
}) // set state to pass to loader prop
};
Router.onRouteChangeComplete = (url) => {
// Some page has finished loading
this.setState({
isLoading: false,
}) // set state to pass to loader prop
};
Router.onRouteChangeError = (err, url) => {
this.setState({isLoading: false,})
};
};
render() {
const {Component, pageProps} = this.props
return (
<div>
{this.state.isLoading ? (
<LoaderOverlay/>
) : (
<Component {...pageProps} />
)}
</div>
)
}
}
export default wrapper.withRedux(MyApp);
_document.jsx
import Document, { Html, Head, Main, NextScript } from 'next/document'
class MyDocument extends Document {
static async getInitialProps(ctx) {
const originalRenderPage = ctx.renderPage
ctx.renderPage = () =>
originalRenderPage({
// useful for wrapping the whole react tree
enhanceApp: (App) => App,
// useful for wrapping in a per-page basis
enhanceComponent: (Component) => Component,
})
// Run the parent `getInitialProps`, it now includes the custom `renderPage`
const initialProps = await Document.getInitialProps(ctx)
return initialProps
}
render() {
return (
<Html lang="en">
<Head>
<link async rel="stylesheet" href="//cdn.jsdelivr.net/npm/semantic-ui#2.4.1/dist/semantic.min.css"/>
</Head>
<body>
<div className={'main-wrapper'}>
<Main />
</div>
<NextScript />
</body>
</Html>
)
}
}
export default MyDocument
Development mode (next dev) is much slower because the routes aren't pre-built.
All delay related to routing assuming you don't have any server side blocking data requirements via getInitialProps, getServerSideProps, should not be present when running production mode with next build followed by next start.
Not sure if you have found a fix for this yet, but I came across this article about "shallow routing". I can't see much improvement in my application when using it, but maybe it will help someone else:
https://nextjs.org/docs/routing/shallow-routing
Hey I think you are in your production mode.
That's why it is slow. But if you will host your site it will be pretty much like react only.
But then also if you want to routing fast
Then npm i next#4.2.3 --save will work fine..
to solve this issue followed the commands:
yarn build/nmp build
yarn start/npm start
I hope this will solve this issue
I am new to React. I am trying to build a page and having like 3 button or img on main page. When I click either one, I shall be routed to another class component. You can treat it like click the icon and route you to another category page (just an example). Below is my structure and partial code I tried. I have no idea how to achieve that, and I googled and seems cannot find the stuff I want.
Structure:
/src
.index.js
.App.js
.BookStore.js
.FruitStore.js
.FoodStore.js
index.js
import React from "react";
import { render } from "react-dom";
import App from "./App";
render(
<App />,
document.getElementById('root')
);
App.js:
import React from "react";
import BookStore from "./BookStore";
const AppContainer = () => {
return (
//do the routing
<BookStore/>
)
};
export default AppContainer;
BookStore.js
export default class BookStore extends React.Component {
}
const contentDiv = document.getElementById("root");
const gridProps = window.gridProps || {};
ReactDOM.render(React.createElement(BookStore , gridProps), contentDiv);
First, you could have a look at the/one react router, e.g. https://reactrouter.com/web/guides/quick-start
However, since you're writing you're new to react, this might be a little too much ...
First, I was wondering why you're using the "ReactDOM" in your indexjs (that seems to be correct), but also in the BookStore.js. I would also recommend to write your components as functions, like your "AppContainer" and not use the class components anymore (or do you really need to do that? - why?). You can use hooks instead to have e.g. state in the components.
You would then need any kind of state in your AppContainer which is used for the routing. Maybe like this:
const AppContainer = () => {
const [showDetail, setShowDetail] = useState();
return <>
{!showDetail && <BookStore onDetail={detail => setShowDetail(detail)} />}
{showDetail && <DetailPage detail={showDetail} onBack={() => setShowDetail(undefined)}}
</>
}
Your AppContainer then has a state wheter or not to show the Bookstore (which is shown when "showDetail" is falsy, or a DetailPage which is shown when showDetail is truthy.
For this to work, your Bookstore needs to provide callbacks to let the AppContainer know that something should change. Very simply it could look like this:
const BookStore = ({onDetail}) => {
return <button onClick={() => onDetail("anything")}>Click me</button>
}
Now when someone clicks the button on the bookstore, it calls the "onDetail" callback, which was set in the AppContainer to set the "showDetail" state. So this one will be updated to "anything" in this case. This will result in a rerender on the AppContainer which will now render a DetailPage component instead.