The Right Way to Load Dynamic Remotes

getOrLoadRemote.js

import { injectScript } from '@module-federation/utilities';
// example of dynamic remote import on server and client
const isServer = typeof window === 'undefined';
//could also use
// getModule({
//   remoteContainer: {
//     global: 'app2',
//     url: 'http://localhost:3002/remoteEntry.js',
//   },
//   modulePath: './sample'
// }).then((sample) => {
//   console.log(sample)
// });
const dynamicContainer = injectScript({
  global: 'checkout',
  url: `http://localhost:3002/_next/static/${
    isServer ? 'ssr' : 'chunks'
  }/remoteEntry.js`,
}).then((container) => {
  return container.get('./CheckoutTitle').then((factory) => {
    return factory();
  });
});

// if you wanted to use it server side/client side in next.js 
const DynamicComponent = React.lazy(() => dynamicContainer);

// eslint-disable-next-line react/display-name
export default (props) => {
  return (
    <>
      <React.Suspense>
        <DynamicComponent />
      </React.Suspense>
      <p>Code from GSSP:</p>
      <pre>{props.code}</pre>
    </>
  );
};

export async function getServerSideProps() {
  return {
    props: {
      code: (await dynamicContainer).default.toString(),
    },
  };
}

Don’t do manual script injection. Webpack has its own script loading function you can access. Check injectScript function in nextjs-MF repo.

It's a nice improvement🤩, much thanks💜💜💜!!! One more question, can we use injectScript directly through npm package now?

I export it as a utility so you can. I’ll be moving it to module-federation/utilities and pushing to npm in near future

its on npm as module-federation/utilities now, readme needs some love -- but its there if you want it.

Could use a PR or two as I've not tested it as a standalone util

https://github.com/module-federation/nextjs-mf/blob/main/packages/utilities/src/utils/common.ts

wowww😍, thank you very much for your tireless efforts.

Hi, @ScriptedAlchemy I found that injectScript function works in dev env, but it will throw __webpack_require__.l is not a function error in prod env. do you have any thoughts?

Hello. I need your help. I recorded a video (https://www.youtube.com/watch?v=CMA6WciiGso) where I show the problem.

The problem is the following.

I used the function from the post to create a "ComponentLoader" - a special component for loading remote components

export function ComponentLoader(props) {
    console.log('0 ComponentLoader - componentName:', props.componentName);
    const {
        componentName,
        ...restProps
    } = props;

    const system = {
        remote: 'Shared',
        url: 'http://localhost:8081/assets/remoteEntry.js',
        module: `./${componentName}`,
    }
    
    if (typeof window !== 'undefined') {
        const Component = React.lazy(loadComponent(system.remote, 'default', system.module, system.url));

        return (
            <ErrorBoundary errorResetFlag={ componentName } >
                <Suspense fallback="loading !">
                    <Component
                        widgetName={ componentName }
                        {...restProps}
                    />
                </Suspense>
            </ErrorBoundary>
        );
    }

    return null;
}

import { getOrLoadRemote } from './getOrLoadRemote';

export const loadComponent = (remote, sharedScope, module, url) => {
  return async () => {
    await getOrLoadRemote(remote, sharedScope, url);
    const container = window[remote];
    const factory = await container.get(module);
    const Module = factory();
    return Module;
  };
};

export const getOrLoadRemote = (remote, shareScope, remoteFallbackUrl = undefined) =>
 new Promise((resolve, reject) => {
   // check if remote exists on window
   if (!window[remote]) {
     // search dom to see if remote tag exists, but might still be loading (async)
     const existingRemote = document.querySelector(`[data-webpack="${remote}"]`);
     // when remote is loaded..
     const onload = originOnload => async () => {
       // check if it was initialized
       if (!window[remote].__initialized) {
         // if share scope doesnt exist (like in webpack 4) then expect shareScope to be a manual object
         if (typeof __webpack_share_scopes__ === 'undefined') {
           // use default share scope object passed in manually
           await window[remote].init(shareScope.default);
         } else {
           // otherwise, init share scope as usual
           await window[remote].init(__webpack_share_scopes__[shareScope]);
         }
         // mark remote as initialized
         window[remote].__initialized = true;
       }
       // resolve promise so marking remote as loaded
       resolve();
       originOnload && originOnload();
     };
     if (existingRemote) {
       // if existing remote but not loaded, hook into its onload and wait for it to be ready
       existingRemote.onload = onload(existingRemote.onload);
       existingRemote.onerror = reject;
       // check if remote fallback exists as param passed to function
       // TODO: should scan public config for a matching key if no override exists
     } else if (remoteFallbackUrl) {
       // inject remote if a fallback exists and call the same onload function
       var d = document,
         script = d.createElement('script');
       script.type = 'text/javascript';
       // mark as data-webpack so runtime can track it internally
       script.setAttribute('data-webpack', `${remote}`);
       script.async = true;
       script.onerror = reject;
       script.onload = onload(null);
       script.src = remoteFallbackUrl;
       d.getElementsByTagName('head')[0].appendChild(script);
     } else {
       // no remote and no fallback exist, reject
       reject(`Cannot Find Remote ${remote} to inject`);
     }
   } else {
     // remote already instantiated, resolve
     resolve();
   }
 });

I use it here:

const sharedComponentsNames = {
    ExampleSharedComponent1: 'ExampleSharedComponent1',
    ExampleSharedComponent2: 'ExampleSharedComponent2',
}

export function ExternalComponentExample(props) {
    console.log('-1 ExternalComponentExampleContainer:', props);

    const { ComponentLoader } = window;

    const dynamicComponentName = sharedComponentsNames.ExampleSharedComponent2;
    
    return (
        <div>
            <div>
                <h1>
                    { dynamicComponentName }
                </h1><br />
                <ComponentLoader
                    componentName={ dynamicComponentName }
                />
            </div>
        </div>
    );
}

everything works fine when I load components at the same level
but when a downloadable component also has a downloadable component - this leads to a lot of re-rendering
it is worth noting that re-rendering is not infinite and sooner or later we all still see the final result

this is how the downloadable components look like

export default function ExampleSharedComponent1(props) {
  console.log('1 ExampleSharedComponent1:', props);
  return (
    <div>
      ExampleSharedComponent_____________1
    </div>
  );
}

export default function ExampleSharedComponent2(props) {
  console.log('1 ExampleSharedComponent2:', props);

  const { ComponentLoader } = window;

  return (
    <div>
      ExampleSharedComponent________2

      <ComponentLoader
          componentName={ 'ExampleSharedComponent1' }
      />
    </div>
  );
}

I'm new to wmf - so I really hope for your help
@ScriptedAlchemy 😢

I think, i found answer in this article - https://dev.to/omher/lets-dynamic-remote-modules-with-webpack-module-federation-2b9m
At the same time, there is no re-rendering with nested loading of modular components.

@shirly-chen-awx Did you ever find a solution to the __webpack_require__.l is not a function? We are experiencing the same strange behavior.

ensure the file is getting bundled by webpack and not treated as external. @oravecz

that error happens when something is importing it outside webpacks scope

Yes, it was a duplicate of module-federation/core#551

I'm surprised it isn't discussed more, especially on the @module-federation/utilities page. importRemote is the function that is calling __webpack_require__.l(), and I would expect any production build using that package would tree-shake away the function without that plugin.

Is this plugin available as an npm published webpack plugin at this time?