Javascript 服务器端使用React中的Next.js加载全局组件

事实上，我找不到任何人问这个问题，这可能意味着我没有完全理解某些东西，或者我正在用错误的关键字搜索，所以如果这是一个愚蠢的问题，请不要咬我的头

我正在粘贴代码的相关部分，但是如果您想要完整示例的回购。完整的问题将在底部。

---

以下是我的文件夹结构：

server.js
/components
    Layout.js
/pages
    contact.js

---

server.js

// tells next which page to load
server.get("/contact/:id", (req, res) => {
    const actualPage = "/contact"
    const queryParams = {id: req.params.id}
    app.render(req, res, actualPage, queryParams)
})

// api uri for grabbing contacts from the database
server.get("/api/contact/:id", (req, res) => {
    Contact.findOne({first_name: req.params.id}, (error, contact) => {
        if (error) return next(error)
        res.status(200).json(contact)
    })
})

const Contact = props => (
    <Layout>
        <h1>{props.contact.first_name} {props.contact.last_name}</h1>
    </Layout>
)

// a static async call passes fetched data into the props
Contact.getInitialProps = async function (context) {
    const {id} = context.query
    const res = await fetch(`http://localhost:3000/api/contact/${id}`)
    const contact = await res.json()
    return {contact: contact}
}

const Layout = (props) =>
<div>
    <div>
        <Link href="/contact/John">
            <a>John</a>
        </Link>
        <Link href="/contact/Jed">
            <a>Jed</a>
        </Link>
        <Link href="/contact/Fred">
            <a>Fred</a>
        </Link>
    </div>
    {props.children}
</div>

页面/contact.js

// tells next which page to load
server.get("/contact/:id", (req, res) => {
    const actualPage = "/contact"
    const queryParams = {id: req.params.id}
    app.render(req, res, actualPage, queryParams)
})

// api uri for grabbing contacts from the database
server.get("/api/contact/:id", (req, res) => {
    Contact.findOne({first_name: req.params.id}, (error, contact) => {
        if (error) return next(error)
        res.status(200).json(contact)
    })
})

const Contact = props => (
    <Layout>
        <h1>{props.contact.first_name} {props.contact.last_name}</h1>
    </Layout>
)

// a static async call passes fetched data into the props
Contact.getInitialProps = async function (context) {
    const {id} = context.query
    const res = await fetch(`http://localhost:3000/api/contact/${id}`)
    const contact = await res.json()
    return {contact: contact}
}

const Layout = (props) =>
<div>
    <div>
        <Link href="/contact/John">
            <a>John</a>
        </Link>
        <Link href="/contact/Jed">
            <a>Jed</a>
        </Link>
        <Link href="/contact/Fred">
            <a>Fred</a>
        </Link>
    </div>
    {props.children}
</div>

---

---

我试图弄清楚是否可以动态查询数据库来构建数据库中文档的导航。我能想到的唯一方法是用每个组件重新渲染整个导航，但这似乎是非常不必要的。同样，如果您想尝试一下代码，.

我可以想到的一种方法是使用并添加

componentDidMount

方法（只触发一次），在该方法中，您可以获取所有联系人，将其存储在app.js state中，并将其传递给页面和组件

\u app.js

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 };
  }

  // store contacts in the state
  state = {
    contacts: undefined
  };

  componentDidMount() {
    // get contacts and store them in the _app.js state
    fetch('some-api/all-contacts-endpoint').then(contacts => {
       this.setState({ contacts });
    });
  }

  render() {
    const { Component, pageProps } = this.props;

    return (
      <Container>
        <Component {...pageProps} contacts={this.state.contacts} />
      </Container>
    );
  }
}

// contacts will be inside props here
const Contact = props => (
  <Layout contacts={props.contacts}>
    <h1>
      {props.contact.first_name} {props.contact.last_name}
    </h1>
  </Layout>
);

// a static async call passes fetched data into the props
Contact.getInitialProps = async function(context) {
  const { id } = context.query;
  const res = await fetch(`http://localhost:3000/api/contact/${id}`);
  const contact = await res.json();
  return { contact: contact };
};

const Layout = ({ contacts = [] }) => (
  <div>
    <div>
      {contacts.map(contact => (
        <Link key={contact.id} href={`/contact/${contact.id}`}>
          <a>{contact.name}</a>
        </Link>
      ))}
    </div>
    {props.children}
  </div>
);

从“React”导入React；
从“next/App”导入应用程序，{Container}；
导出默认类MyApp扩展应用程序{
静态异步getInitialProps（{Component，router，ctx}）{
让pageProps={}；
if（Component.getInitialProps）{
pageProps=等待组件.getInitialProps（ctx）；
}
返回{pageProps}；
}
//在状态中存储联系人
状态={
联系人：未定义
};
componentDidMount（）{
//获取联系人并将其存储在_app.js状态
fetch（'some-api/all contacts端点'）。然后（contacts=>{
this.setState（{contacts}）；
});
}
render（）{
const{Component，pageProps}=this.props；
返回(
);
}
}

页面/contact.js

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 };
  }

  // store contacts in the state
  state = {
    contacts: undefined
  };

  componentDidMount() {
    // get contacts and store them in the _app.js state
    fetch('some-api/all-contacts-endpoint').then(contacts => {
       this.setState({ contacts });
    });
  }

  render() {
    const { Component, pageProps } = this.props;

    return (
      <Container>
        <Component {...pageProps} contacts={this.state.contacts} />
      </Container>
    );
  }
}

// contacts will be inside props here
const Contact = props => (
  <Layout contacts={props.contacts}>
    <h1>
      {props.contact.first_name} {props.contact.last_name}
    </h1>
  </Layout>
);

// a static async call passes fetched data into the props
Contact.getInitialProps = async function(context) {
  const { id } = context.query;
  const res = await fetch(`http://localhost:3000/api/contact/${id}`);
  const contact = await res.json();
  return { contact: contact };
};

const Layout = ({ contacts = [] }) => (
  <div>
    <div>
      {contacts.map(contact => (
        <Link key={contact.id} href={`/contact/${contact.id}`}>
          <a>{contact.name}</a>
        </Link>
      ))}
    </div>
    {props.children}
  </div>
);

//联系人将位于此处的道具内
const Contact=props=>(
{props.contact.first_name}{props.contact.last_name}
);
//静态异步调用将获取的数据传递到props
Contact.getInitialProps=异步函数（上下文）{
const{id}=context.query；
const res=等待取数(`http://localhost:3000/api/contact/${id}`）；
const contact=wait res.json（）；
返回{contact:contact}；
};

组件/Layout.js

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 };
  }

  // store contacts in the state
  state = {
    contacts: undefined
  };

  componentDidMount() {
    // get contacts and store them in the _app.js state
    fetch('some-api/all-contacts-endpoint').then(contacts => {
       this.setState({ contacts });
    });
  }

  render() {
    const { Component, pageProps } = this.props;

    return (
      <Container>
        <Component {...pageProps} contacts={this.state.contacts} />
      </Container>
    );
  }
}

// contacts will be inside props here
const Contact = props => (
  <Layout contacts={props.contacts}>
    <h1>
      {props.contact.first_name} {props.contact.last_name}
    </h1>
  </Layout>
);

// a static async call passes fetched data into the props
Contact.getInitialProps = async function(context) {
  const { id } = context.query;
  const res = await fetch(`http://localhost:3000/api/contact/${id}`);
  const contact = await res.json();
  return { contact: contact };
};

const Layout = ({ contacts = [] }) => (
  <div>
    <div>
      {contacts.map(contact => (
        <Link key={contact.id} href={`/contact/${contact.id}`}>
          <a>{contact.name}</a>
        </Link>
      ))}
    </div>
    {props.children}
  </div>
);

const布局=（{contacts=[]}）=>(
{contacts.map（contact=>(
{contact.name}
))}
{props.children}
);

---

希望这有帮助

您的意思是要根据DB值构建动态导航，如

/contact/John

、

/contact/Jed

、

/contact/X

和

/contact/Y

？或者你的意思是你想一次预加载所有联系人并通过某个id显示不同的联系人详细信息？我想从DB值构建一个动态nav。