nx/docs/shared/react-tutorial/07-share-code.md
2022-03-16 18:22:54 +00:00

94 lines
2.8 KiB
Markdown

# React Nx Tutorial - Step 7: Share Code
<iframe loading="lazy" width="560" height="315" src="https://www.youtube.com/embed/-zzw4_oT_2I" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture; fullscreen"></iframe>
Awesome! The application is working end to end! However, there is a problem. Both the backend and the frontend define the `Todo` interface. The interface is in sync now, but in a real application, over time, it diverges, and, as a result, runtime errors creep in. You should share this interface between the backend and the frontend. In Nx, you do this by creating a library.
**Run the following generator to create a library:**
```bash
npx nx g @nrwl/workspace:lib data
```
The result should look like this:
```treeview
myorg/
├── apps/
│ ├── todos/
│ ├── todos-e2e/
│ └── api/
├── libs/
│ └── data/
│ ├── src/
│ │ ├── lib/
│ │ │ └── data.ts
│ │ └── index.ts
│ ├── jest.config.js
│ ├── project.json
│ ├── tsconfig.json
│ ├── tsconfig.lib.json
│ └── tsconfig.spec.json
├── tools/
├── nx.json
├── package.json
└── tsconfig.base.json
```
**Copy the interface into `libs/data/src/lib/data.ts`.**
```typescript
export interface Todo {
title: string;
}
```
### A note about VS Code :
If you're using [VS Code](https://code.visualstudio.com/) it may be necessary at this point to restart the TS server so that the new `@myorg/data` package is recognised. This may need to be done **every time a new workspace library is added**. If you install the [Nx Console](/using-nx/console) extension you won't need to take this step.
## Refactor the API
**Now update `apps/api/src/app/todos.ts` to import the interface:**
```typescript
import { Express } from 'express';
import { Todo } from '@myorg/data';
const todos: Todo[] = [{ title: 'Todo 1' }, { title: 'Todo 2' }];
export function addTodoRoutes(app: Express) {
app.get('/api/todos', (req, resp) => resp.send(todos));
app.post('/api/addTodo', (req, resp) => {
const newTodo = {
title: `New todo ${Math.floor(Math.random() * 1000)}`,
};
todos.push(newTodo);
resp.send(newTodo);
});
}
```
## Update the React application
**Next import the interface in `apps/todos/src/app/app.tsx`:**
```typescript
import { useEffect, useState } from 'react';
import { Todo } from '@myorg/data';
export const App = () => {
...
};
export default App;
```
Every time you add a new library, you have to restart `npx nx serve`.
**So restart both `npx nx serve api` and `npx nx serve todos` and you should see the application running.**
## What's Next
- Continue to [Step 8: Create Libraries](/react-tutorial/08-create-libs)