mapStateToProps not updating

Question

I am just beginning to play with react/redux. I just want to input some text and hit submit and then pass that to another component that will display whatever was input.

I know I can get the data from point A to B because if I use store.subscribe than I can access the state and it is always accurate. I am trying to use mapStateToProps though and I am not having any luck.

I am not using mapDispatchToProps so maybe that is an issue? I cant seem to find a good simple example. mapStateToProps also only seems to run when I refresh the page (using webpack-dev-server) since it only logs one time on page load and never again.

_______________ Input.js _________________

import React from 'react';
import store from '../redux/store';
import { connect } from 'react-redux';
import { addSearchParam } from '../redux/actions';

export default class Input extends React.Component {

  constructor(props) {
    super(props);
    this.state = {
      player: ''
    };

    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  handleChange(event) {
    this.setState({
      player: event.target.value
    });
  }

  handleSubmit(event) {
    event.preventDefault();
    store.dispatch(addSearchParam(this.state.player))
  }

  render() {
    return ( <form onSubmit = {this.handleSubmit} >
      <label>
          <input type="text" value={this.state.player} 
          onChange={this.handleChange}/> 
      </label> 
      <input type="submit" value="Submit" />
      </form>
    );
  }
}


_______________ Info.js _________________


import React from 'react';
import store from '../redux/store';
import { connect } from 'react-redux';

class Info extends React.Component {

  constructor(props) {
    super(props);
  }

  render() {
    return ( 
        <h2> {this.props.player}</h2>
    )
  }
}

function mapStateToProps(state) {
  console.log("mapStateToPropsInfo: ", state)
  return {
    player: state.player
  }
}

export default connect(mapStateToProps, null)(Info);


_______________ reducers.js _________________

'use strict';

import {
  combineReducers
} from 'redux';

const SEARCH_PARAM = 'SEARCH_PARAM';

const searchReducer = (state = '', action) => {
  if (action.type === SEARCH_PARAM) {
    return action.text;
  }
  return state;
}

export const reducers = combineReducers({
  searchReducer
})

export default reducers;


_______________ actions.js _________________

'use-strict';

export const addSearchParam = input => {
  return {
    type: 'SEARCH_PARAM',
    id: 'player',
    text: input
  }
}

_______________ index.js _________________
'use-strict';

import React from 'react';
import ReactDOM from 'react-dom';
import App from './js/App';
import { Provider } from 'react-redux';
import { createStore } from 'redux';
import reducers from './js/redux/reducers'

let store = createStore(reducers)

ReactDOM.render(
    <Provider store={store}>
        <App />
  	    </Provider>, document.getElementById('root')
);

Those seem to be the most important files related to this problem but I can provide more if necessary. Thanks for any help. Hopefully im just missing something simple.

Answer 1

I think the issue is that you have written actions but never used/connected it. You need to use mapDispatchToProps in Input.js.

First import the action in input.js like this:

import { addSearchParam } from './actions';

Write mapDispatchToProps function like this:

function mapDispatchToProps(dispatch){
    return bindActionCreators({addSearchParam}, dispatch);
}

Then, inside Input.js in handleSubmit function do this:

this.props.addSearchParam(this.state.player)                

Also, instead of exporting class while declearing, change export statement of Input.js to also bind the mapDispatchToProps :

export default connect(null, mapDispatchToProps)(Input);