# Dynamic load provider
Modern.js provides [Data Loader](https://modernjs.dev/en/guides/basic-features/data/data-fetch.html#data-loader-recommended) to help For data management, `Data Loader` is only executed on the server side and will not be executed repeatedly on the client side.
This chapter will introduce how to use `Data Loader` to obtain producer information and load it dynamically.
## Create provider
Create a new provider for dynamic load.
### 1. Create configuration file
Create a `module-federation.config.ts` file in the project root directory and write the following content:
```ts title='module-federation.config.ts'
import { createModuleFederationConfig } from '@module-federation/modern-js-v3';
export default createModuleFederationConfig({
name: 'dynamic_provider',
filename: 'remoteEntry.js',
exposes: {
'./Image': './src/components/Image.tsx',
},
shared: {
react: { singleton: true },
'react-dom': { singleton: true },
},
});
```
### 2. Apply plugin
Apply `@module-federation/modern-js-v3` in `modern.config.ts`:
```ts title='modern.config.ts'
import { appTools, defineConfig } from '@modern-js/app-tools';
import { moduleFederationPlugin } from '@module-federation/modern-js-v3';
// https://modernjs.dev/en/configure/app/usage
export default defineConfig({
server: {
ssr: {
mode: 'stream',
},
port: 3008,
},
plugins: [appTools(), moduleFederationPlugin()],
});
```
### 3. Create need to be exposed component
Create the file `src/components/Image.tsx` with the following content:
```tsx title='Image.tsx'
import React from 'react';
import styles from './Image.module.css';
export default (): JSX.Element => (
<div
id="remote-components"
style={{
backgroundColor: '#c0e91e',
color: 'lightgrey',
padding: '1rem',
}}
>
<h2>
<strong>dynamic remote</strong> image
</h2>
<button
id="dynamic-remote-components-button"
style={{ marginBottom: '1rem' }}
onClick={() => alert('[remote-components] Client side Javascript works!')}
>
Click me to test i'm interactive!
</button>
<img
id="dynamic-remote-components-image"
src="https://module-federation.io/module-federation-logo.svg"
style={{ width: '100px' }}
alt="serge"
/>
<button className={styles['button']}>Button from dynamic remote</button>
</div>
);
```
And create the corresponding style file, the content is as follows:
```css title='Image.module.css'
.button {
background: red;
}
```
## Create loader
Create a `.data` file with the same name in the corresponding routing file. Taking the root directory `src/routes/page.tsx` as an example, create `src/routes/page.data.ts`:
```ts title='page.data.ts'
import { LoaderFunctionArgs } from '@modern-js/runtime/router';
export type DataLoaderRes = {
providerList: Array<{
name: string,
entry: string,
id: string;
}>
}
const fetchProviderList = async () => {
const res = await new Promise(resolve => {
setTimeout(() => {
resolve([
{
name: 'dynamic_provider',
entry: 'http://localhost:3008/mf-manifest.json',
id: 'dynamic_provider/Image'
}
])
}, 1000);
});
return res as DataLoaderRes['providerList']
}
export const loader = async ({ request }: LoaderFunctionArgs): Promise<DataLoaderRes> => {
console.log('request params', request);
const providerList = await fetchProviderList();
return {
providerList
}
};
```
## Load dynamic provider
Consume loader data and dynamically load the corresponding producer:
```tsx
import { loadRemote, registerRemotes, getInstance } from '@module-federation/modern-js-v3/runtime';
import { createLazyComponent } from '@module-federation/modern-js-v3/react';
// Use import type to get data loader types
import type { DataLoaderRes } from './page.data';
import { useLoaderData } from '@modern-js/runtime/router';
import './index.css';
const RemoteSSRComponent = createLazyComponent({
instance: getInstance(),
loader: () => import('remote/Image'),
loading: 'loading...',
export: 'default',
fallback: ({ error }) => {
if (error instanceof Error && error.message.includes('not exist')) {
return <div>fallback - not existed id</div>;
}
return <div>fallback</div>;
},
});
const Index = () => {
// get data loader response
const dataLoader = useLoaderData() as DataLoaderRes;
// register dynamic remotes before loading them
registerRemotes(dataLoader.providerList);
const DynamicRemoteSSRComponents = dataLoader.providerList.map(item => {
const { id } = item;
const Com = createLazyComponent({
instance: getInstance(),
loader: () => loadRemote(id),
loading: 'loading...',
fallback: ({ error }) => {
if (error instanceof Error && error.message.includes('not exist')) {
return <div>fallback - not existed id</div>;
}
return <div>fallback</div>;
},
});
return <Com />
})
return (
<div className="container-box">
<RemoteSSRComponent />
{DynamicRemoteSSRComponents}
</div>
);
}
export default Index;
```
