Extract Local State into Redux

JavaScript
1 
// Redux:
const ADD = 'ADD';

const addMessage = (message) => {
  return {
    type: ADD,
    message: message
  }
};

const messageReducer = (state = [], action) => {
  switch (action.type) {
    case ADD:
      return [
        ...state,
        action.message
      ];
    default:
      return state;
  }
};

const store = Redux.createStore(messageReducer);

// React:
const Provider = ReactRedux.Provider;
const connect = ReactRedux.connect;

// Change code below this line
class Presentational extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      input: '',
    }
    this.handleChange = this.handleChange.bind(this);
    this.submitMessage = this.submitMessage.bind(this);
  }
  handleChange(event) {
    this.setState({
      input: event.target.value
    });
  }
  submitMessage() {

    // get the dispatch funtion from props and execute with input value
        this.props.submitNewMessage(this.state.input)

    //clear the input value
    this.setState((state) => ({
      input: '',
    }));
  }
  render() {
    return (
      <div>
        <h2>Type in a new Message:</h2>
        <input
          value={this.state.input}
          onChange={this.handleChange}/><br/>
        <button onClick={this.submitMessage}>Submit</button>
        <ul>
        {/*change the state.messages for store state messages*/}
          {store.getState().map( (message, idx) => {
              return (
                 <li key={idx}>{message}</li>
              )
            })
          }
        </ul>
      </div>
    );
  }
};
// Change code above this line

const mapStateToProps = (state) => {
  return {messages: state}
};

const mapDispatchToProps = (dispatch) => {
  return {
    submitNewMessage: (message) => {
      dispatch(addMessage(message))
    }
  }
};

const Container = connect(mapStateToProps, mapDispatchToProps)(Presentational);

class AppWrapper extends React.Component {
  render() {
    return (
      <Provider store={store}>
        <Container/>
      </Provider>
    );
  }
};
2

Please Tell us what’s happening in your own words.

Learning to describe problems is hard, but it is an important part of learning how to code.

Also, the more you say, the more we can help!

1 Like
3

i just comment the line that i working on because the parctice give to you the rest .

4

Do you have a question about this code?

5

yes about mapDispatchToProps i don’t understand when i get the dispatch method

6

Not sure I understand what you mean by “when i get the dispatch method”.

connect passes it to the mapDispatchToProps function, dispatch is on the store. In the component you now have access to the submitNewMessage (instead of dispatch).

7

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