--description--
In the last challenge, you created a Redux store to handle the messages array and created an action for adding new messages. The next step is to provide React access to the Redux store and the actions it needs to dispatch updates. React Redux provides its react-redux
package to help accomplish these tasks.
React Redux provides a small API with two key features: Provider
and connect
. Another challenge covers connect
. The Provider
is a wrapper component from React Redux that wraps your React app. This wrapper then allows you to access the Redux store
and dispatch
functions throughout your component tree. Provider
takes two props, the Redux store and the child components of your app. Defining the Provider
for an App component might look like this:
<Provider store={store}>
<App/>
</Provider>
--instructions--
The code editor now shows all your Redux and React code from the past several challenges. It includes the Redux store, actions, and the DisplayMessages
component. The only new piece is the AppWrapper
component at the bottom. Use this top level component to render the Provider
from ReactRedux
, and pass the Redux store as a prop. Then render the DisplayMessages
component as a child. Once you are finished, you should see your React component rendered to the page.
Note: React Redux is available as a global variable here, so you can access the Provider with dot notation. The code in the editor takes advantage of this and sets it to a constant Provider
for you to use in the AppWrapper
render method.
--hints--
The AppWrapper
should render.
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(AppWrapper));
return mockedComponent.find('AppWrapper').length === 1;
})()
);
The Provider
wrapper component should have a prop of store
passed to it, equal to the Redux store.
(getUserInput) =>
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(AppWrapper));
return __helpers
.removeWhiteSpace(getUserInput('index'))
.includes('<Providerstore={store}>');
})()
);
DisplayMessages
should render as a child of AppWrapper
.
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(AppWrapper));
return (
mockedComponent.find('AppWrapper').find('DisplayMessages').length === 1
);
})()
);
The DisplayMessages
component should render an h2
, input
, button
, and ul
element.
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(AppWrapper));
return (
mockedComponent.find('div').length === 1 &&
mockedComponent.find('h2').length === 1 &&
mockedComponent.find('button').length === 1 &&
mockedComponent.find('ul').length === 1
);
})()
);
--seed--
--after-user-code--
ReactDOM.render(<AppWrapper />, document.getElementById('root'))
--seed-contents--
// Redux:
const ADD = 'ADD';
const addMessage = (message) => {
return {
type: ADD,
message
}
};
const messageReducer = (state = [], action) => {
switch (action.type) {
case ADD:
return [
...state,
action.message
];
default:
return state;
}
};
const store = Redux.createStore(messageReducer);
// React:
class DisplayMessages extends React.Component {
constructor(props) {
super(props);
this.state = {
input: '',
messages: []
}
this.handleChange = this.handleChange.bind(this);
this.submitMessage = this.submitMessage.bind(this);
}
handleChange(event) {
this.setState({
input: event.target.value
});
}
submitMessage() {
this.setState((state) => {
const currentMessage = state.input;
return {
input: '',
messages: state.messages.concat(currentMessage)
};
});
}
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>
{this.state.messages.map( (message, idx) => {
return (
<li key={idx}>{message}</li>
)
})
}
</ul>
</div>
);
}
};
const Provider = ReactRedux.Provider;
class AppWrapper extends React.Component {
// Render the Provider below this line
// Change code above this line
};
--solutions--
// Redux:
const ADD = 'ADD';
const addMessage = (message) => {
return {
type: ADD,
message
}
};
const messageReducer = (state = [], action) => {
switch (action.type) {
case ADD:
return [
...state,
action.message
];
default:
return state;
}
};
const store = Redux.createStore(messageReducer);
// React:
class DisplayMessages extends React.Component {
constructor(props) {
super(props);
this.state = {
input: '',
messages: []
}
this.handleChange = this.handleChange.bind(this);
this.submitMessage = this.submitMessage.bind(this);
}
handleChange(event) {
this.setState({
input: event.target.value
});
}
submitMessage() {
this.setState((state) => {
const currentMessage = state.input;
return {
input: '',
messages: state.messages.concat(currentMessage)
};
});
}
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>
{this.state.messages.map( (message, idx) => {
return (
<li key={idx}>{message}</li>
)
})
}
</ul>
</div>
);
}
};
const Provider = ReactRedux.Provider;
class AppWrapper extends React.Component {
// Change code below this line
render() {
return (
<Provider store = {store}>
<DisplayMessages/>
</Provider>
);
}
// Change code above this line
};