Next JS Layout 组件，将 props 传递给 children

Question

I have found a code that solved my problem in Next JS re rendering when changing pages. But now i need to send props to the children component. I got no idea how i can make it works here, this is my layout.js code. As you can see i can send props to Header component but for children i dont know how, because it is a variable and not a component.

import Header from "../components/header";
import Footer from "../components/footer";
import { Fragment } from "react";

export default function Layout({ children, ...pageProps }) {
  return (
    <Fragment>
      <Header
        isRegisterPage={pageProps.isRegisterPage}
        isLoginPage={pageProps.isLoginPage}
        outHome={pageProps.outHome}
      />
      {children}
      <Footer />
    </Fragment>
  );
}

Thank you for the help

Answer 1

Have you considered using React's Context API? The idea is that when using the Context API your component's state get's lifted, to be managed at a global scale. If a component needs a prop, instead of passing props down manually (prop drilling) you can simply wrap you component in what's known as a context provider. This will allow that Component to access the global state of your application. This is good because, when your application gets bigger, you may need to pass props down through many components which can clutter and add unneeded confusion.

React provides some great documentation to set your React application up to use the Context API. Highly recommend checking it out!

https://reactjs.org/docs/context.html

Answer 2

Try this

import Header from "../components/header";
import Footer from "../components/footer";
import { Fragment } from "react";

export default function Layout({ children, ...pageProps }) {

  function recursiveMap(children, fn) {
    return React.Children.map(children, child => {
      if (!React.isValidElement(child) || typeof child.type == 'string') {
        return child;
      }
  
      if (child.props.children) {
        child = React.cloneElement(child, {
          children: recursiveMap(child.props.children, fn)
        });
      }
  
      return fn(child);
    });
  }

  // Add props to all child elements.
  const childrenWithProps = recursiveMap(children, child => {
    // Checking isValidElement is the safe way and avoids a TS error too.
    if (isValidElement(child)) {
      // Pass additional props here
      return cloneElement(child, { currentUser: { ...user } })
    }

    return child;
  });

  return (
    <Fragment>
      <Header
        isRegisterPage={pageProps.isRegisterPage}
        isLoginPage={pageProps.isLoginPage}
        outHome={pageProps.outHome}
      />
      {childrenWithProps}
      <Footer />
    </Fragment>
  );
}

Answer 3

You can use React's cloneElement to achieve that.

React.cloneElement(children, {
    isRegisterPage: pageProps.isRegisterPage,
    isLoginPage: pageProps.isLoginPage,
    outHome: pageProps.outHome
})

Complete example in your case:

import Header from "../components/header";
import Footer from "../components/footer";
import React, { Fragment } from "react";

export default function Layout({ children, ...pageProps }) {
  return (
    <Fragment>
      <Header
        isRegisterPage={pageProps.isRegisterPage}
        isLoginPage={pageProps.isLoginPage}
        outHome={pageProps.outHome}
      />
      {
          React.cloneElement(children, {
              isRegisterPage: pageProps.isRegisterPage,
              isLoginPage: pageProps.isLoginPage,
              outHome: pageProps.outHome
          })
      }
      <Footer />
    </Fragment>
  );
}

Answer 4

From the answer of Lucas Raza, below is an example that uses Context API to apply themes to different components

1.Create a context File

//ThemeContex.js
import { createContext, useState } from "react";

export const ThemeContext = createContext();

export const withThemeContext = Component => {
    const WrappedComp = props => {
  
        const [darkColor,lightColor] = ["#3b3b3b", "#ddd"]
        const [lightBackgoround,darkBackgoround] = ["#ececec","#1d2a35"]       

        const darkTheme = {
            backgroundColor: darkBackgoround,
            color:lightColor,
        }

        const lightTheme = {
            backgroundColor: lightBackgoround,
            color:darkColor,
        }

        const themes = {
            darkTheme, lightTheme
        }
    
        const [theme, setTheme] = useState(lightTheme)

    
        const children ={
            theme,
            themes, 
            setTheme,
        }
    
        return(
            <StylesContext.Provider value={{...children}} >
                <Component {...props} />    
            </StylesContext.Provider>
        )
    }
    
    return WrappedComp;
}

2. In _app.js, import withThemeContext higher component and wrap MyApp with it when exporting it.

    import { withThemeContext } from '../components' function MyApp({ Component, pageProps }) { return <Component {...pageProps} /> } export default withThemeContext(MyApp)

3. You can know use theme any where in a component

    import { useContext } from 'react' import {ThemeContext} from '../components' export default function Home() { const { theme } =useContext(ThemeContext) return ( <div id="home" style={theme}> // Home logic... </div> ) }