Directly Training Frontend

Directly training app, is an application with webpack, react and redux to make additions, deletions, and modifications from users.

Prerequisites

Ubuntu

install npm version, node >= 8

• sudo apt-get update
• sudo apt-get install nodejs
• sudo apt-get install npm

Also, you can use nvm node version management tool

install yarn latest

• curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
• echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
• sudo apt-get update && sudo apt-get install yarn

Windows

• Install npm
• Install yarn

Start application

• Install packages npm install or yarn install
• Run app: npm start or yarn start
• By default, the application starts on http://localhost:8080
• The backend is integrated with the API MS BE with heroku you can check the repo here: MS BE Repository
• You can point to the local backend with the file app/constants.js

For now don't commit this .env.development or constants.js file changes

Commands

install packages

npm install

start app

npm start

Dev tools

run tests

npm test

run test with watch

test:dev

linter rules

npm run lint

sass rules

npm run sass-lint

build from production

npm run build

High Order Components

A higher-order component (HOC) is an advanced technique in React for reusing component logic. HOCs are not part of the React API, per se. They are a pattern that emerges from React’s compositional nature.

Documentation about HOC pattern

How does it work?

Concretely, a higher-order component is a function that takes a component and returns a new component.

const EnhancedComponent = higherOrderComponent(WrappedComponent);

Use HOCs For Cross-Cutting Concerns

Components are the primary unit of code reuse in React. However, you’ll find that some patterns aren’t a straightforward fit for traditional components.

Subscriber

class CommentList extends React.Component {
  constructor(props) {
    super(props);
    this.handleChange = this.handleChange.bind(this);
    this.state = {
      // "DataSource" is some global data source
      comments: DataSource.getComments()
    };
  }

  componentDidMount() {
    // Subscribe to changes
    DataSource.addChangeListener(this.handleChange);
  }

  componentWillUnmount() {
    // Clean up listener
    DataSource.removeChangeListener(this.handleChange);
  }

  handleChange() {
    // Update component state whenever the data source changes
    this.setState({
      comments: DataSource.getComments()
    });
  }

  render() {
    return (
      <div>
        {this.state.comments.map((comment) => (
          <Comment comment={comment} key={comment.id} />
        ))}
      </div>
    );
  }
}

Subscriptor

// This function takes a component...
function withSubscription(WrappedComponent, selectData) {
  // ...and returns another component...
  return class extends React.Component {
    constructor(props) {
      super(props);
      this.handleChange = this.handleChange.bind(this);
      this.state = {
        data: selectData(DataSource, props)
      };
    }

    componentDidMount() {
      // ... that takes care of the subscription...
      DataSource.addChangeListener(this.handleChange);
    }

    componentWillUnmount() {
      DataSource.removeChangeListener(this.handleChange);
    }

    handleChange() {
      this.setState({
        data: selectData(DataSource, this.props)
      });
    }

    render() {
      // ... and renders the wrapped component with the fresh data!
      // Notice that we pass through any additional props
      return <WrappedComponent data={this.state.data} {...this.props} />;
    }
  };
}

Consumer

const CommentListWithSubscription = withSubscription(
  CommentList,
  (DataSource) => DataSource.getComments()
);

For now don't commit this .env.development or constants.js file changes

If you need to work with the current ms-labs-be app request access to

Mariano Ravinale

Emanuel Pereyra