gwuiinkim / react16

React 16

4가지 feature

Fragment

불필요하게 span등의 태그로 감쌀 필요가 없어졌다. 그리고 <> 이런식으로 감쌀 수도 있게 됨. ( 별로 사용되지 않을 수도 있지만 string을 return할 수도 있다.)

Portal. #root 이외의 element도 react를 통해서 변경할 수 있다.

Error Boundaries

자식 Component의 error를 handle 할 수 있게 되었다. error가 발생해도 전체 react app이 다 죽어버리는 것이 아니라, 에러가 난 부분만 isolate해서 처리할 수 있다. 하지만 각 Component 마다 다 customize 하기 보다는 아래와 같은 형태로 한 곳으로 묶어주는 것이 좋다.

const BoundaryHOC = ProtectedComponent =>
  class Boundary extends Component {
    state = {
      hasError: false
    };
    componentDidCatch = () => {
      this.setState({
        hasError: true
      });
    };
    render() {
      const { hasError } = this.state;
      if (hasError) {
        return <ErrorFallback />;
      } else {
        return <ProtectedComponent />;
      }
    }
  };

this.setState(null)

state에 null을 return함으로써, Component가 더 이상 update 되는 것을 막는다! Component를 변경하는 것이 아니라, Component가 update되는 것을 막는것.

This project was bootstrapped with Create React App.

Available Scripts

In the project directory, you can run:

npm start

Runs the app in the development mode.
Open http://localhost:3000 to view it in the browser.

The page will reload if you make edits.
You will also see any lint errors in the console.

npm test

Launches the test runner in the interactive watch mode.
See the section about running tests for more information.

npm run build

Builds the app for production to the build folder.
It correctly bundles React in production mode and optimizes the build for the best performance.

The build is minified and the filenames include the hashes.
Your app is ready to be deployed!

See the section about deployment for more information.

npm run eject

Note: this is a one-way operation. Once you eject, you can’t go back!

If you aren’t satisfied with the build tool and configuration choices, you can eject at any time. This command will remove the single build dependency from your project.

Instead, it will copy all the configuration files and the transitive dependencies (Webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except eject will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.

You don’t have to ever use eject. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.

Learn More

You can learn more in the Create React App documentation.

To learn React, check out the React documentation.

Code Splitting

This section has moved here: https://facebook.github.io/create-react-app/docs/code-splitting

Analyzing the Bundle Size

This section has moved here: https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size

Making a Progressive Web App

This section has moved here: https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app

Advanced Configuration

This section has moved here: https://facebook.github.io/create-react-app/docs/advanced-configuration

Deployment

This section has moved here: https://facebook.github.io/create-react-app/docs/deployment

npm run build fails to minify

This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify