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Server Side Rendering

Server Side Rendering (SSR) can improve the first-load performance of your application. Reactive Data Client takes this one step further by pre-populating the data store. Unlike other SSR methodologies, Reactive Data Client becomes interactive the moment the page is visible, making data mutations instantaneous. Additionally there is no need for additional data fetches that increase server load and slow client hydration, potentially causing application stutters.

NextJS SSR​

App Router​

NextJS 12 includes a new way of routing in the '/app' directory. This allows further performance improvements, as well as dynamic and nested routing.

Root Layout​

Place DataProvider in your root layout

app/layout.tsx
import { DataProvider } from '@data-client/react/nextjs';
import { AsyncBoundary } from '@data-client/react';

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        <DataProvider>
          <header>Title</header>
          <AsyncBoundary>{children}</AsyncBoundary>
          <footer></footer>
        </DataProvider>
      </body>
    </html>
  );
}

Client Components​

To keep your data fresh and performant, you can use client components and useSuspense()

app/todos/[userId]/page.tsx
'use client';
import { useSuspense } from '@data-client/react';
import { TodoResource } from '@/resources/Todo';

export default function InteractivePage({ params }: { params: { userId: number } }) {
  const todos = useSuspense(TodoResource.getList, params);
  return <TodoList todos={todos} />;
}

Note that this is identical to how you would write components without SSR. This makes makes the components usable across platforms.

Server Components​

However, if your data never changes, you can slightly decrease the javascript bundle sent, by using a server component. Simply await the endpoint:

app/todos/[userId]/page.tsx
import { TodoResource } from '@/resources/Todo';

export default async function StaticPage({ params }: { params: { userId: number } }) {
  const todos = await TodoResource.getList(params);
  return <TodoList todos={todos} />;
}

Demo​

More Demos

Class mangling and Entity.key​

NextJS will rename classes for production builds. Due to this, it's critical to define Entity.key as its default implementation is based on the class name.

class User extends Entity {
  id = '';
  username = '';

  static key = 'User';
}

Pages Router​

With NextJS < 14, you might be using the pages router. For this we have Document and NextJS specific wrapper for App

npm install --save @data-client/ssr @data-client/redux redux
pages/_document.tsx
import { DataClientDocument } from '@data-client/ssr/nextjs';

export default DataClientDocument;
pages/_app.tsx
import { AppDataProvider } from '@data-client/ssr/nextjs';
import type { AppProps } from 'next/app';

export default function App({ Component, pageProps }: AppProps) {
  return (
    <AppDataProvider>
      <Component {...pageProps} />
    </AppDataProvider>
  );
}
warning

When fetching from parameters from useRouter(), you will need to add getServerSideProps to avoid NextJS setting router.query to nothing

export default function MyComponent() {
  const id: string; = useRouter().query.id;
  const post = useSuspense(getPost, { id });
  // etc
}
export const getServerSideProps = () => ({ props: {} });

Further customizing Document​

To further customize Document, simply extend from the provided document.

Make sure you use super.getInitialProps() instead of Document.getInitialProps() or the Reactive Data Client code won't run!

pages/_document.tsx
import { Html, Head, Main, NextScript } from 'next/document';
import { DataClientDocument } from '@data-client/ssr/nextjs';

export default class MyDocument extends DataClientDocument {
  static async getInitialProps(ctx) {
    const originalRenderPage = ctx.renderPage;

    // Run the React rendering logic synchronously
    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 super.getInitialProps(ctx);

    return initialProps;
  }

  render() {
    return (
      <Html>
        <Head />
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    );
  }
}

CSP Nonce​

Reactive Data Client Document serializes the store state in a script tag. In case you have Content Security Policy restrictions that require use of a nonce, you can override DataClientDocument.getNonce.

Since there is no standard way of handling nonce in NextJS, this allows you to retrieve any nonce you created in the DocumentContext to use with Reactive Data Client.

pages/_document.tsx
import { DataClientDocument } from '@data-client/ssr/nextjs';
import type { DocumentContext } from 'next/document.js';

export default class MyDocument extends DataClientDocument {
  static getNonce(ctx: DocumentContext & { res: { nonce?: string } }) {
    // this assumes nonce has been added here - customize as you need
    return ctx?.res?.nonce;
  }
}

Express JS SSR​

When implementing your own server using express.

Server side​

import express from 'express';
import { renderToPipeableStream } from 'react-dom/server';
import {
  createPersistedStore,
  createServerDataComponent,
} from '@data-client/react/ssr';

const rootId = 'react-root';

const app = express();
app.get('/*', (req: any, res: any) => {
  const [ServerDataProvider, useReadyCacheState, controller] =
    createPersistedStore();
  const ServerDataComponent =
    createServerDataComponent(useReadyCacheState);

  controller.fetch(NeededForPage, { id: 5 });

  const { pipe, abort } = renderToPipeableStream(
    <Document
      assets={assets}
      scripts={[<ServerDataComponent key="server-data" />]}
      rootId={rootId}
    >
      <ServerDataProvider>{children}</ServerDataProvider>
    </Document>,

    {
      onCompleteShell() {
        // If something errored before we started streaming, we set the error code appropriately.
        res.statusCode = didError ? 500 : 200;
        res.setHeader('Content-type', 'text/html');
        pipe(res);
      },
      onError(x: any) {
        didError = true;
        console.error(x);
        res.statusCode = 500;
        pipe(res);
      },
    },
  );
  // Abandon and switch to client rendering if enough time passes.
  // Try lowering this to see the client recover.
  setTimeout(abort, 1000);
});

app.listen(3000, () => {
  console.log(`Listening at ${PORT}...`);
});

Client​

import { hydrateRoot } from 'react-dom';
import { awaitInitialData } from '@data-client/react/ssr';

const rootId = 'react-root';

awaitInitialData().then(initialState => {
  hydrateRoot(
    document.getElementById(rootId),
    <DataProvider initialState={initialState}>{children}</DataProvider>,
  );
});